GPS/XM Weather Question

[Kyle Boatright]

For those of you who have XM weather integrated with your GPS.

Do you use the weather information to paint a big picture of what's going on
around you. I.E. "If I fly 50 miles thataway, it looks like I'll be able to
circumvent this line of storms."

Or, do you us it on a more detailed level. E.G. "There is a two mile
corridor between these two cells, I'm gonna buzz right between 'em."

Realistically, since there is a delay between when the radar picture was
taken and when you got the information, how close are you comfortable
cutting things when relying on XM weather?

[Peter R.]

Kyle Boatright > wrote:

> For those of you who have XM weather integrated with your GPS.

What about those of us who have WSI downlinked NEXRAD displayed on moving
maps? Are we qualified to answer or are you specifically interested in XM
users only?

--
Peter

[Andrew Sarangan[_1_]]

Nexrad XM datalink could be as much as 10 minutes old. So, no, you
cannot use it to buzz between cells. It is a strategic tool, not a
tactical tool. Flying 50 miles thataway is a much better plan.


Kyle Boatright wrote:
> For those of you who have XM weather integrated with your GPS.
>
> Do you use the weather information to paint a big picture of what's going on
> around you. I.E. "If I fly 50 miles thataway, it looks like I'll be able to
> circumvent this line of storms."
>
> Or, do you us it on a more detailed level. E.G. "There is a two mile
> corridor between these two cells, I'm gonna buzz right between 'em."
>
> Realistically, since there is a delay between when the radar picture was
> taken and when you got the information, how close are you comfortable
> cutting things when relying on XM weather?

[Mark Manes]

Kyle,

I have XM via the Garmin 396 and in the panel mounted Avidyne EX 500. They
both display the same nexrad but with the 396 I get more useful information
(cloud cover, storm cell heights & direction of movement, airmet & sigmet /w
text and more). The ideal use is to avoid the areas of bad stuff, which is
how I always intend to use the information. That being said, it has gotten
me thru some tight spots and around cells while in IMC. I would have been in
those situations even without the XM weather, so I was very glad to have it
available. I would never suggest that downloaded NEXRAD be used to pick a
2 mile corridor between 2 cells but it is a nice thing to have when things
do get nasty. I did a lot of observation of storm cells while in VMC and the
NEXRAD was quite accurate (all this was done before paying any attention to
it while in IMC). It's just another tool but only to be relied on to avoid
bad areas not to pick your way around bad things.

Mark
N28409
WC5I

"Kyle Boatright" > wrote in message
...
> For those of you who have XM weather integrated with your GPS.
>
> Do you use the weather information to paint a big picture of what's going
> on around you. I.E. "If I fly 50 miles thataway, it looks like I'll be
> able to circumvent this line of storms."
>
> Or, do you us it on a more detailed level. E.G. "There is a two mile
> corridor between these two cells, I'm gonna buzz right between 'em."
>
> Realistically, since there is a delay between when the radar picture was
> taken and when you got the information, how close are you comfortable
> cutting things when relying on XM weather?
>
>
>

[Kyle Boatright]

"Peter R." > wrote in message
...
> Kyle Boatright > wrote:
>
>> For those of you who have XM weather integrated with your GPS.
>
> What about those of us who have WSI downlinked NEXRAD displayed on moving
> maps? Are we qualified to answer or are you specifically interested in XM
> users only?
>
> --
> Peter

All answers are welcome. I'm simply trying to get a feel for the usefulness
of this kind of technology.

KB

[Ron Natalie]

Kyle Boatright wrote:
> For those of you who have XM weather integrated with your GPS.

I've got XM on the MX20
>
> Do you use the weather information to paint a big picture of what's going on
> around you. I.E. "If I fly 50 miles thataway, it looks like I'll be able to
> circumvent this line of storms."

I frequently zoom out to see "if it's bad out there" however, trying
to use NEXRAD to pick your way through things is folly. In military
sense, it's more STRATEGIC than TACTICAL.

>
> Or, do you us it on a more detailed level. E.G. "There is a two mile
> corridor between these two cells, I'm gonna buzz right between 'em."
>
Two miles would be cutting it close (especially if they were t-storms).

[Viperdoc[_3_]]

I have on board radar as well as Nexrad. As all of the others have said, the
XM is good for the big picture, but on board radar is more useful for
avoiding cells up close.

This is particularly true at night, when the radar becomes more important in
IMC. Both of them have important information, but separate applications.

[Peter R.]

Ron Natalie > wrote:

> I've got XM on the MX20

Ron, what are you using for your XM receiver, a Garmin x96 or some other
receiver?

Also, what weather products are available on the MX20 using the XM
receiver? NEXRAD, TAFs, and METARs, obviously, but what about lightning,
satellite images, winds aloft, and pireps?

Since WSI reversed engineered weather into the Garmin GNS430/530, Garmin
stopped offering MX20 software updates for WSI weather, which prevented the
display of the newer WSI weather features such as lightning, pireps, winds
aloft, etc.

--
Peter

[Peter R.]

Kyle Boatright > wrote:


> I'm simply trying to get a feel for the usefulness
> of this kind of technology.

I had the WSI receiver displaying graphical and textual weather on the MX20
moving map installed in my Bonanza two years ago and have been using the
aircraft heavily to commute for my business, flying at least twice a week
for the last two years (about 95% of the total time) in the Northeast US.

Disregarding for a moment my belief that I chose the "Betamax" of the
downlinked weather technology, I am continually impressed with how
downlinked NEXRAD allows me to launch more confidentially. As long as the
refresh rates remain within the 4 minute period (the WSI sometimes doesn't,
especially on long x/c's across the US mainland), the big weather picture
is accurate enough to give me the information to make proper decisions.

Last year, I was about 20 minutes outside my home airport when two t-storm
cells merged into one large one right over the airport. I could see the
tops of the storm up ahead, but the NEXRAD provided me with the fact that
the cell actually sat right over the airport (as opposed to being east or
west of it).

In watching a few refreshed screens, it was clear that the cell was not
moving that fast, so I requested a diversion to an airport to the south (I
was IFR), where I landed and waited about 30 minutes for the cell to
finally move northwest of my home airport.

I have plenty of similar experiences but in summary, if you want more
utility out of your aircraft, the confidence to have the big weather
picture and you fly outside your local traffic pattern, you should
seriously consider installing downlinked NEXRAD (IMOandE, of course).

--
Peter

[Jim Burns]

I compare the XM big picture with our stormscope and my eyeballs (if I can).
I'd never use any of the above to buzz between two "cells". I will use it,
to a point and in non convective situations, to direct me towards lower
levels of rain intensity. It is a great tool for inflight decision making.

Recently on a flight from MI to WI across LM, a storm was working it's way
from south western WI northeast up through the Madison area. As we left MI,
we saw it developing and noted how slow it was traveling. ATC was
announcing Airmets and Sigmets for our entire route due to the approaching
storm. The XM weather not only let us avoid it, but showed us that we
wouldn't even need to deviate our course due to the slow movement. The
storm stayed south long enough for us to get home and we never came within
30 miles of it. The storm dumped over 3" of rain on Madison while we flew
ahead of it through layered CU. Without XM we probably would have sat in MI
watching the Weather Channel and waiting for that monster to pass.

My experience is that XM makes more flights possible and manageable, but it
is in no way an excuse to get any closer to thunderstorms than you would
when you can see them out your window.
Jim

"Kyle Boatright" > wrote in message
...
> For those of you who have XM weather integrated with your GPS.
>
> Do you use the weather information to paint a big picture of what's going
> on around you. I.E. "If I fly 50 miles thataway, it looks like I'll be
> able to circumvent this line of storms."
>
> Or, do you us it on a more detailed level. E.G. "There is a two mile
> corridor between these two cells, I'm gonna buzz right between 'em."
>
> Realistically, since there is a delay between when the radar picture was
> taken and when you got the information, how close are you comfortable
> cutting things when relying on XM weather?
>
>
>

[Ron Natalie]

Peter R. wrote:
> Ron Natalie > wrote:
>
>> I've got XM on the MX20
>
> Ron, what are you using for your XM receiver, a Garmin x96 or some other
> receiver?

It's a GDL69A. XM weather plus XM radio audio (gotta have something to
listen to the ball games on now that I ditched the ADF).

>
> Also, what weather products are available on the MX20 using the XM
> receiver? NEXRAD, TAFs, and METARs, obviously, but what about lightning,
> satellite images, winds aloft, and pireps?

It's got Lightning and winds aloft for sure. I'm pretty sure it
doesn't have satellite images. I've not dirlled down into the text
screens too much other than METAR, but I know it has METAR, TAF, and
TFR's (there's maybe a half dozen things in the list).

[Dan Luke]

"Kyle Boatright" wrote:

> For those of you who have XM weather integrated with your GPS.
>
> Do you use the weather information to paint a big picture of what's going
> on around you. I.E. "If I fly 50 miles thataway, it looks like I'll be
> able to circumvent this line of storms."

Yep.

> Or, do you us it on a more detailed level. E.G. "There is a two mile
> corridor between these two cells, I'm gonna buzz right between 'em."

Maybe not that tight. It depends on the size and movement of the cells and
whether they're growing ir dying.

> Realistically, since there is a delay between when the radar picture was
> taken and when you got the information, how close are you comfortable
> cutting things when relying on XM weather?

The best I can tell you is "it depends." I've used XM to do a lot of
zig-zagging among air mass CBs. I would not use it to try to sneak through
a hole in a squall line.

--
Dan
C172RG at BFM

[Dan Luke]

"Jim Burns" wrote:

> My experience is that XM makes more flights possible and manageable, but
> it is in no way an excuse to get any closer to thunderstorms than you
> would when you can see them out your window.

Well put.

But I would add that XM's best advantage is giving you a picture of the CBs
you *can't* see out your window.

--
Dan
C172RG at BFM

[Jim Burns]

Agreed. I also think that it's much more beneficial in IFR to have a second
source of weather such as a Stormscope or such to help delineate between
rain and actual thunderstorms.
Jim

"Dan Luke" > wrote in message
...
>
> "Jim Burns" wrote:
>
>> My experience is that XM makes more flights possible and manageable, but
>> it is in no way an excuse to get any closer to thunderstorms than you
>> would when you can see them out your window.
>
> Well put.
>
> But I would add that XM's best advantage is giving you a picture of the
> CBs you *can't* see out your window.
>
> --
> Dan
> C172RG at BFM
>

[Dan Luke]

"Kyle Boatright" wrote:

> All answers are welcome. I'm simply trying to get a feel for the
> usefulness of this kind of technology.

It would be difficult to overestimate it, IMO.

I tend to gush about it, because I live in one of the most
thunderstorm-afflicted areas of the U. S. To me, it is the greatest thing
since GPS. Put the two together, and the cross country utility of a light
airplane takes a quantum jump.

--
Dan
C172RG at BFM

[Viperdoc[_3_]]

I am fortunate to have XM Nexrad, stormscope, and onboard radar. I have used
these in combination, including night IMC. They all provide valuable
information, and in combination give a lot of information.

In particular, the combination of Stormscope and Nexrad overlayed are
especially useful. However, up close and for use for navigating between
cells, especially at night or in IMC, nothing beats the on board radar for
real time situational awareness.

[Ron Natalie]

Dan Luke wrote:
> "Andrew Sarangan" wrote:
>
>> Nexrad XM datalink...is a strategic tool, not a
>> tactical tool.
>
> That is the conventional wisdom, but I suspect it comes more from lawyers
> than from pilots experienced with using datalinked NEXRAD.

I used the same wording and I have XM weather and have used it.

>
> I use XM NEXRAD tactically all the time. If there's a growing cell 15 miles
> ahead, I will use the NEXRAD picture to decide whether to go left or right
> around it based on its history and the location of other cells beyond it.
> That's tactical, to me, and it's the best thing about having satellite
> weather aboard.
>

That's strategy not tactics.

[Jonathan Goodish]

In article >,
Ron Natalie > wrote:
> >> Nexrad XM datalink...is a strategic tool, not a
> >> tactical tool.
> >
> > That is the conventional wisdom, but I suspect it comes more from lawyers
> > than from pilots experienced with using datalinked NEXRAD.
>
> I used the same wording and I have XM weather and have used it.

I believe you're not an instrument pilot? I suspect you use it quite
differently than Dan, or other instrument pilots who are often engaged
in weather flying.

That being said, I certainly wouldn't rely on NEXRAD alone to weave my
way through a line of cells. NEXRAD + Echo Tops + Sferics would get me
closer, but I'm not sure that I'd take the risk of close-in deviations
without the live picture (sferics + airborne radar).





> > I use XM NEXRAD tactically all the time. If there's a growing cell 15
> > miles
> > ahead, I will use the NEXRAD picture to decide whether to go left or right
> > around it based on its history and the location of other cells beyond it.
> > That's tactical, to me, and it's the best thing about having satellite
> > weather aboard.
> >
>
> That's strategy not tactics.

Making enroute decisions to deviate based on uplinked information?
Sounds like tactics to me.





JKG

[.Blueskies.]

"Andrew Sarangan" > wrote in message oups.com...
:
: Nexrad XM datalink could be as much as 10 minutes old. So, no, you
: cannot use it to buzz between cells. It is a strategic tool, not a
: tactical tool. Flying 50 miles thataway is a much better plan.
:


Is there some sort of time marker on the screen to indicate the time the last data was updated, or to indicate how old
it is?

[.Blueskies.]

"Jim Burns" > wrote in message ...
: Agreed. I also think that it's much more beneficial in IFR to have a second
: source of weather such as a Stormscope or such to help delineate between
: rain and actual thunderstorms.
: Jim
:
:

Yes the lightening strikes tell the tale. What is the difference between Stormscope strikes and ones displayed from XM?

[Dan Luke]

"Ron Natalie" wrote:

>>
>> I use XM NEXRAD tactically all the time. If there's a growing cell 15
>> miles ahead, I will use the NEXRAD picture to decide whether to go left
>> or right around it based on its history and the location of other cells
>> beyond it. That's tactical, to me, and it's the best thing about having
>> satellite weather aboard.
>>
>
> That's strategy not tactics.

You have your definition; I have mine.

--
Dan
C172RG at BFM

[Dan Luke]

".Blueskies." wrote:

> : Nexrad XM datalink could be as much as 10 minutes old. So, no, you
> : cannot use it to buzz between cells. It is a strategic tool, not a
> : tactical tool. Flying 50 miles thataway is a much better plan.
> :
>
>
> Is there some sort of time marker on the screen to indicate the time the
> last data was updated, or to indicate how old
> it is?

Yes.

[Dan Luke]

".Blueskies." wrote:

> Yes the lightening strikes tell the tale. What is the difference between
> Stormscope strikes and ones displayed from XM?

Luggage left on the ramp tells the lightening tale ;) (sorry)

Lightning depicted on XM is triangulated from ground sensors. It is very
accurate, but it is not real-time like spherics and does not display all
cloud discharges.

A stormscope--properly installed and interpreted--may tip you off about a
cell that is getting convective a bit before XM will. On the other hand, XM
lightning display is not subject to spurious signals or radial spread.

In practice I have found the XM lightning feature quite useful. It would be
nice to have both, but if I have to pick just one, I prefer the XM.

--
Dan
C172RG at BFM

[Ron Natalie]

..Blueskies. wrote:
> "Andrew Sarangan" > wrote in message oups.com...
> :
> : Nexrad XM datalink could be as much as 10 minutes old. So, no, you
> : cannot use it to buzz between cells. It is a strategic tool, not a
> : tactical tool. Flying 50 miles thataway is a much better plan.
> :
>
>
> Is there some sort of time marker on the screen to indicate the time the last data was updated, or to indicate how old
> it is?
>
>
On the MX20 XM FIS display the time is on the right side bottom of the
display for NEXAD (and if you have it overlaid, the METAR flags).

[Jonathan Goodish]

In article >,
".Blueskies." > wrote:

> "Jim Burns" > wrote in message
> ...
> : Agreed. I also think that it's much more beneficial in IFR to have a
> : second
> : source of weather such as a Stormscope or such to help delineate between
> : rain and actual thunderstorms.
> : Jim
> :
> :
>
> Yes the lightening strikes tell the tale. What is the difference between
> Stormscope strikes and ones displayed from XM?

I hate to disagree with Dan, who otherwise provides excellent comments
on XM weather, but in my personal experience the Lightning product is
not that impressive. I have a StrikeFinder and a Garmin 396, and the
StrikeFinder MOST DEFINITELY picks up quite a bit that the Lightning
product misses. I'm not just talking about stuff that's building, I'm
talking about established cells which show as RED on NEXRAD but with no
XM lightning depiction.

The comments about real-time versus delayed data are also accurate. If
I recall correctly, the StrikeFinder cost me around $4500 installed
several years ago. Today, I'm not sure that I'd spend that money on
sferics now that I have XM weather, based upon the type of flying that I
do. However, having both devices, it has been quite illuminating as to
how much the XM lightning product misses.



JKG

[Jay Honeck]

> For those of you who have XM weather integrated with your GPS.
>
> Do you use the weather information to paint a big picture of what's going on
> around you. I.E. "If I fly 50 miles thataway, it looks like I'll be able to
> circumvent this line of storms."

Mary and I are very new to XM, but have already used it on several
x-country flights, including one today that highlighted some weaknesses
in the system.

We flew from Racine, WI to Iowa City, IA, about a 1.5 hour flight,
depending on winds. A cold front was approaching from the north, with
a very juicy airmass in place to the south. Flight service indicated
good VFR all the way, leaving Racine around 7 PM. This would put us on
the ground right around sunset, which was our goal.

Using the airport's computer, the satellite pic showed no cloud-cover
over our route of flight at all. This, of course, was contradicted by
our Mark V eyeballs, and METARs that indicated a broken to overcast
layer at around 2800 feet, all the way from the Mississippi east to our
position on the western shore of Lake Michigan. Visibilities ranged
from 7 to 10 miles along the route of flight when we launched.

The XM weather on the 496 takes around ten minutes to upload, which
meant that we were already airborne by the time we were getting useful
weather. Although this is something we will learn to work around, I
find this time lag to be a bother. (I know, much wants more!) We're
going to have to get in the habit of turning on the 496 before engine
start, to allow time for downloading.

We were soon buzzing along under the overcast in smooth air but really
crappy visibility (especially when the sun would occasionally break
through and hit that moist, tropical air), and we were really glad when
the METARs finally downloaded into the Garmin.

We've mounted the 496 on the co-pilot's yoke, so Mary was working the
GPS for the first time, but had only minimal difficulties navigating
Garmin's excellent menus. She laughed when she was able to look at the
"live" satellite photo, which (like the one in the airport) showed
nothing but clear, blue skies ahead, while we were obviously under a
pretty thick overcast.

Strike one for XM. Apparently with a thin-but-solid overcast, the
satellite photo data is worse than useless. In fact, it shows perfectly
clear skies where none exist. (Given the same faulty presentation on
the airport's computer, I'm prepared to accept that this is not a flaw
in XM weather -- but it *is* a flaw, nonetheless.)

She then started checking METAR data ahead, to make sure that things
weren't falling apart along our route of flight. Having this data on
board is priceless, IMHO, and it showed that conditions were stable
until the Mississippi, and then improved dramatically to the west.
Obtaining this data is as easy as running your cursor over a little
triangle next to each reporting station, and having it in the plane was
a major reason for purchasing the 496.

However, after 30 minutes in the air, she noticed that the METAR data
had not updated. The NEXRAD radar and satellite data were updating
every 6 minutes or so, but the METARs remained the same as when they
initially uploaded.

Obviously, in changing flight conditions this slow rate of change is
simply unacceptable, and we quickly reverted to listening to AWOS's
ahead on the radio.

Strike two for XM.

By the time we hit the Big Muddy, we were able to climb on top of the
layer, which rapidly diminished to a thick haze layer. The rest of the
flight was uneventful, and we didn't refer to the 496 again.

IMHO, the jury is still out on the unit. It's wonderful for
watching/avoiding precipitation and storms, to be sure, but it
certainly proved to be less than useful on this flight. And I can
assure you that we fly in these kinds of fuzzy VFR conditions FAR more
often than we do when thunderstorms are threatening.

I'm going to contact Garmin about the update rate on METARs, and hope
there's some setting or software update I can install to improve the
rate of change. If it can't be improved, the unit will end up being far
less useful than expected.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Peter Duniho]

"Jay Honeck" > wrote in message
oups.com...
> [...]
> Strike one for XM. Apparently with a thin-but-solid overcast, the
> satellite photo data is worse than useless. In fact, it shows perfectly
> clear skies where none exist. (Given the same faulty presentation on
> the airport's computer, I'm prepared to accept that this is not a flaw
> in XM weather -- but it *is* a flaw, nonetheless.)

I'd say that's a pretty sure indication that the satellite imagery itself
was defective. I don't know what might have caused that, but normally it
should be reliable, and I don't think you can blame that on the XM weather
stuff. They can't give you information that's not available.

> [...]
> However, after 30 minutes in the air, she noticed that the METAR data
> had not updated. The NEXRAD radar and satellite data were updating
> every 6 minutes or so, but the METARs remained the same as when they
> initially uploaded.

When you called the FSS on the radio to obtain the latest METARs, were you
able to get more recent information (by a significant time period) than was
available from the XM weather? As I'm sure you know, METARs are only
updated once an hour at airports with an ATIS (unless conditions change
significantly), and where an automated observation system is used, the
updates may or may not happen frequently.

If the FSS doesn't have information that is significantly more recent than
that available from XM weather, then again I don't think you can blame that
on XM weather.

In both of these cases, the obvious comparison is between the XM weather and
what the FSS can tell you. They have the same satellite imagery, so if
their computers show clouds when XM doesn't, that'd be a problem. Likewise,
if they have METARs more recent than XM does, that'd be a problem.

Otherwise, it seems to me that XM is giving you the best information
available, and the problem lies in what information is actually available.
The real value for the XM weather is to provide a nice graphical description
of the data that the FSS can provide, and without having to use the radio.
Not having the most up-to-date information would be the fault of the FSS,
NOAA, NWS, etc.

If you didn't call the FSS on the radio to compare the information, then it
must not have been that important to you in the first place and so I'd
wonder why it's such a problem for XM to not provide it.

Pete

[Jay Honeck]

> > Strike one for XM. Apparently with a thin-but-solid overcast, the
> > satellite photo data is worse than useless. In fact, it shows perfectly
> > clear skies where none exist. (Given the same faulty presentation on
> > the airport's computer, I'm prepared to accept that this is not a flaw
> > in XM weather -- but it *is* a flaw, nonetheless.)
>
> I'd say that's a pretty sure indication that the satellite imagery itself
> was defective. I don't know what might have caused that, but normally it
> should be reliable

Actually, I've noticed this many times in the past. Satellite photos
will show clear skies while we are actually beneath a solid overcast.
I don't know if the operators can selectively set the sensitivity of
the camera to not show thin layers, or what, but this isn't the first
time that satellite imagery of cloud cover has been 100% wrong.

> > However, after 30 minutes in the air, she noticed that the METAR data
> > had not updated. The NEXRAD radar and satellite data were updating
> > every 6 minutes or so, but the METARs remained the same as when they
> > initially uploaded.
>
> When you called the FSS on the radio to obtain the latest METARs, were you
> able to get more recent information (by a significant time period) than was
> available from the XM weather?

We reverted to listening to AWOS and ASOS reporting stations, which
update every minute or so. I don't expect the 496 to be THAT quick or
accurate, but I would hope that XM could update METARs more often than
hourly.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Ron Natalie]

Peter Duniho wrote:

>
> I'm not sure what "operators" you think are there. The data comes in from a
> satellite as a photographic image, and that image is relayed as the
> satellite photo. There's not some guy sitting there tweaking the brightness
> and contrast or something.
>
There aren't operators intervening most likely, but the data is far from
a simple "photographic image." The thing is intensity adjusted, noised
filtered, and geometrically remapped before it comes out in the format
that you see it in weathermation or whatever.

> The METARs are not within XM's control\

Yes, I'm not sure what the filter is, but there seems to be some
filter on the thing just watching it at our local field. The
weather gets listed on the external sites hourly unless something
changes a lot, but I haven't figured out what it is, and how long
it waits after it thinks things have changed it waits to see if
the change was transient or worth reporting.

[Bob Noel]

In article . com>,
"Jay Honeck" > wrote:

> Using the airport's computer, the satellite pic showed no cloud-cover
> over our route of flight at all. This, of course, was contradicted by
> our Mark V eyeballs, and METARs that indicated a broken to overcast
> layer at around 2800 feet,

IIRC visible satellite images will show low clouds as very dark... the bright
clouds are higher. Are you sure it showed no cloud-cover?

--
Bob Noel
Looking for a sig the
lawyers will hate

[Rich Badaracco]

Jay Honeck wrote:

> However, after 30 minutes in the air, she noticed that the METAR data
> had not updated. The NEXRAD radar and satellite data were updating
> every 6 minutes or so, but the METARs remained the same as when they
> initially uploaded.

According to XM the update rate for the Metars is 12 minutes. In my
experience using the system if the airport has an ATIS the weather info
that is displayed will the the ATIS info and not the current conditions.
I'm not sure if that is what you were seeing. This was one of the
shortcomings I found with the system when it first came out. It's good
for monitoring trends in the weather but not actual conditions. To
answer the original question this is why I use it as a strategic tool
and not tactical.

[Jay Honeck]

> IIRC visible satellite images will show low clouds as very dark... the bright
> clouds are higher. Are you sure it showed no cloud-cover?

Both Mary and I looked at the same picture on the Weathermation
computer at Racine's Batten Field, which showed clear skies from
Michigan to Iowa, when, in fact, the entire area was under a relatively
low (2500 - 3000 foot) thin (500 - 1000 foot thick) overcast.

The info on the 496 displayed the same way.

I suppose the low clouds happened to display in the same color as the
ground, but that would seem to be less than helpful.

;-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[karl gruber[_1_]]

"Jay Honeck" > wrote in message
oups.com...
>> For those of you who have XM weather integrated with your GPS.
>>
>> Do you use the weather information to paint a big picture of what's going
>> on
>> around you. I.E. "If I fly 50 miles thataway, it looks like I'll be able
>> to
>> circumvent this line of storms."

The satellite image is an infrared image with all the limitations infrared
has, but it works at night............thus a night image is still available.

METAR is just that. A METAR only gets updated every hour unless there is a
special. Complain to the FAA.

Karl
"Curator" N185KG

[Jose[_1_]]

> which showed clear skies from
> Michigan to Iowa, when, in fact, the entire area was under a relatively
> low (2500 - 3000 foot) thin (500 - 1000 foot thick) overcast.

Maybe it was thin enough to be transparant when looked at from above,
but not when looked at lengthwise.

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.

[Casey Wilson[_1_]]

"Jay Honeck" > wrote in message
ps.com...
>> > Strike one for XM. Apparently with a thin-but-solid overcast, the
>> > satellite photo data is worse than useless. In fact, it shows perfectly
>> > clear skies where none exist. (Given the same faulty presentation on
>> > the airport's computer, I'm prepared to accept that this is not a flaw
>> > in XM weather -- but it *is* a flaw, nonetheless.)
>>
>> I'd say that's a pretty sure indication that the satellite imagery itself
>> was defective. I don't know what might have caused that, but normally it
>> should be reliable
>
> Actually, I've noticed this many times in the past. Satellite photos
> will show clear skies while we are actually beneath a solid overcast.
> I don't know if the operators can selectively set the sensitivity of
> the camera to not show thin layers, or what, but this isn't the first
> time that satellite imagery of cloud cover has been 100% wrong.

Hi Jay and Mary,

Without appearing to defend the XM Weather technology, here's my put on
what you are seeing based on my experiences in another life working with
some sophisticated and 'spooky' equipment.
Satellite "images" used to construct Wx displays are generally collected
with LWIR [Long Wavelength InfraRed -- 8 to 13 microns] imaging radiometers.
Water vapor [cloud] is generally transparent in the LWIR while percipitation
[rain, snow, etc.] is not. That's why the Wx images displayed can show rain
but not the clouds that drop it. Same with the microwave displays, i.e.
RADAR.
Here's the first hint: you can get the same type of displays on a full
dark night.

What is Atlas' tail number again? I might be coming your way next month.

Regards,

Casey Wilson
Freelance Writer
and Photographer

[Jon Kraus]

As much as you fly you (or the little woman) should really think about
finally getting your Instrument Ratings. This way you won't have to
worry about any overcast's and go happily on your way. Just a thought.

As far as METARS go I believe that unless there is a significant change
they only update once an hour. XM doesn't create METAR's they just
display the information.

Sounds a little bit like you were expecting the 496 to be a panacea for
all things weather and it turns out to be just a system of displaying
information you could get from other sources.

Jon Kraus
'79 Mooney 201
4443H @ UMP

Jay Honeck wrote:
>>For those of you who have XM weather integrated with your GPS.
>>
>>Do you use the weather information to paint a big picture of what's going on
>>around you. I.E. "If I fly 50 miles thataway, it looks like I'll be able to
>>circumvent this line of storms."
>
>
> Mary and I are very new to XM, but have already used it on several
> x-country flights, including one today that highlighted some weaknesses
> in the system.
>
> We flew from Racine, WI to Iowa City, IA, about a 1.5 hour flight,
> depending on winds. A cold front was approaching from the north, with
> a very juicy airmass in place to the south. Flight service indicated
> good VFR all the way, leaving Racine around 7 PM. This would put us on
> the ground right around sunset, which was our goal.
>
> Using the airport's computer, the satellite pic showed no cloud-cover
> over our route of flight at all. This, of course, was contradicted by
> our Mark V eyeballs, and METARs that indicated a broken to overcast
> layer at around 2800 feet, all the way from the Mississippi east to our
> position on the western shore of Lake Michigan. Visibilities ranged
> from 7 to 10 miles along the route of flight when we launched.
>
> The XM weather on the 496 takes around ten minutes to upload, which
> meant that we were already airborne by the time we were getting useful
> weather. Although this is something we will learn to work around, I
> find this time lag to be a bother. (I know, much wants more!) We're
> going to have to get in the habit of turning on the 496 before engine
> start, to allow time for downloading.
>
> We were soon buzzing along under the overcast in smooth air but really
> crappy visibility (especially when the sun would occasionally break
> through and hit that moist, tropical air), and we were really glad when
> the METARs finally downloaded into the Garmin.
>
> We've mounted the 496 on the co-pilot's yoke, so Mary was working the
> GPS for the first time, but had only minimal difficulties navigating
> Garmin's excellent menus. She laughed when she was able to look at the
> "live" satellite photo, which (like the one in the airport) showed
> nothing but clear, blue skies ahead, while we were obviously under a
> pretty thick overcast.
>
> Strike one for XM. Apparently with a thin-but-solid overcast, the
> satellite photo data is worse than useless. In fact, it shows perfectly
> clear skies where none exist. (Given the same faulty presentation on
> the airport's computer, I'm prepared to accept that this is not a flaw
> in XM weather -- but it *is* a flaw, nonetheless.)
>
> She then started checking METAR data ahead, to make sure that things
> weren't falling apart along our route of flight. Having this data on
> board is priceless, IMHO, and it showed that conditions were stable
> until the Mississippi, and then improved dramatically to the west.
> Obtaining this data is as easy as running your cursor over a little
> triangle next to each reporting station, and having it in the plane was
> a major reason for purchasing the 496.
>
> However, after 30 minutes in the air, she noticed that the METAR data
> had not updated. The NEXRAD radar and satellite data were updating
> every 6 minutes or so, but the METARs remained the same as when they
> initially uploaded.
>
> Obviously, in changing flight conditions this slow rate of change is
> simply unacceptable, and we quickly reverted to listening to AWOS's
> ahead on the radio.
>
> Strike two for XM.
>
> By the time we hit the Big Muddy, we were able to climb on top of the
> layer, which rapidly diminished to a thick haze layer. The rest of the
> flight was uneventful, and we didn't refer to the 496 again.
>
> IMHO, the jury is still out on the unit. It's wonderful for
> watching/avoiding precipitation and storms, to be sure, but it
> certainly proved to be less than useful on this flight. And I can
> assure you that we fly in these kinds of fuzzy VFR conditions FAR more
> often than we do when thunderstorms are threatening.
>
> I'm going to contact Garmin about the update rate on METARs, and hope
> there's some setting or software update I can install to improve the
> rate of change. If it can't be improved, the unit will end up being far
> less useful than expected.
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"
>

[Dan Luke]

"Jon Kraus" wrote:

> As much as you fly you (or the little woman) should really think about
> finally getting your Instrument Ratings. This way you won't have to worry
> about any overcast's and go happily on your way. Just a thought.

Indeed. I've got the satellite image feature turned off because I don't need
it; the clouds just get in the way of other stuff on the screen.

--
Dan
C-172RG at BFM

[.Blueskies.]

"Peter Duniho" > wrote in message ...

:
: As I already said, all that XM does for you is show you the data in a
: friendlier way, and avoid the radio call to the FSS. Expecting more from
: them is unreasonable and will guarantee disappointment on your part.
:
: Pete
:
:

All said and done, I still consider the monthly ~$30 charge to be a user fee of sorts. You can call FSS on the radio or
pay the fee and receive the same info. More convenient to use the GPS? Maybe for some...

[Ron Natalie]

..Blueskies. wrote:
> "Peter Duniho" > wrote in message ...
>
> :
> : As I already said, all that XM does for you is show you the data in a
> : friendlier way, and avoid the radio call to the FSS. Expecting more from
> : them is unreasonable and will guarantee disappointment on your part.
> :
> : Pete
> :
> :
>
> All said and done, I still consider the monthly ~$30 charge to be a user fee of sorts. You can call FSS on the radio or
> pay the fee and receive the same info. More convenient to use the GPS? Maybe for some...
>
>
>
I dunno, I have much better luck loading weather on the MX20 than
I have communicating with Flight Watch/FSS over the radio. And
the graphical presentation is much easier.

[.Blueskies.]

"Ron Natalie" > wrote in message m...
: .Blueskies. wrote:
: > "Peter Duniho" > wrote in message ...
: >
: > :
: > : As I already said, all that XM does for you is show you the data in a
: > : friendlier way, and avoid the radio call to the FSS. Expecting more from
: > : them is unreasonable and will guarantee disappointment on your part.
: > :
: > : Pete
: > :
: > :
: >
: > All said and done, I still consider the monthly ~$30 charge to be a user fee of sorts. You can call FSS on the radio
or
: > pay the fee and receive the same info. More convenient to use the GPS? Maybe for some...
: >
: >
: >
: I dunno, I have much better luck loading weather on the MX20 than
: I have communicating with Flight Watch/FSS over the radio. And
: the graphical presentation is much easier.

I agree about the graphical representation... picture says a thousand words...

[Peter Duniho]

"Ron Natalie" > wrote in message
m...
> There aren't operators intervening most likely, but the data is far from
> a simple "photographic image." The thing is intensity adjusted, noised
> filtered, and geometrically remapped before it comes out in the format
> that you see it in weathermation or whatever.

I understand that there is image processing to make it suitable for
presentation in a given format. But that doesn't mean that there's someone
dropping clouds from the picture when they are there originally.

[Peter Duniho]

".Blueskies." > wrote in message
t...
> All said and done, I still consider the monthly ~$30 charge to be a user
> fee of sorts. You can call FSS on the radio or
> pay the fee and receive the same info. More convenient to use the GPS?
> Maybe for some...

Well, I don't do enough cross-country flying these days to justify the cost,
but certainly back when I did, I would have loved the convenience and
probably would've found $30 to be reasonable. It can sometimes be a hassle
just getting the FSS to reply on either Flight Watch or an RCO, depending on
how busy they are, and even once you do, you are basically relying on them
to be able to describe in words the situation.

For some things, like METARs and TAFs, the language barrier isn't a problem,
but when dealing with graphical depictions of things like rain, lightning,
or even clouds (as non-useful as I think the cloud picture is most of the
time :) ), there's no substitute for a good picture. To be able to present
the picture in real-time relative to your course (planned or current) is
even better, and something you just can't get using the FSS directly.

I guess it depends on your definition of "user fee", but I don't see it that
way. First, the fee isn't being paid to the government...it's being paid to
a commercial service offering something that the government doesn't provide,
even if the underlying data is from the government. Second, we pay the
government for a variety of other services now, mostly related to charting.
I've never heard anyone complain about "user fees" when buying sectionals,
A/FDs, WACs, IFR charts or approach plates, nor have I ever heard anyone
describe Jeppesen's product as being paid for with "user fees".

Pete

[Peter Duniho]

"Bob Noel" > wrote in message
...
> IIRC visible satellite images will show low clouds as very dark... the
> bright
> clouds are higher. Are you sure it showed no cloud-cover?

Visible satellite should not vary in brightness according to altitude. But
infrared does. Perhaps the XM images are from the infrared satellite, as
Casey suggests.

[Jonathan Goodish]

In article . com>,
"Jay Honeck" > wrote:
> Obviously, in changing flight conditions this slow rate of change is
> simply unacceptable, and we quickly reverted to listening to AWOS's
> ahead on the radio.
>
> Strike two for XM.

I suspect that the METAR data was being updated as expected, but the
METARs don't change but once an hour, unless there's a SPECI issued.
Same data as is available from flight service or DUATS.



JKG

[Jonathan Goodish]

In article >,
".Blueskies." > wrote:
> : As I already said, all that XM does for you is show you the data in a
> : friendlier way, and avoid the radio call to the FSS. Expecting more from
> : them is unreasonable and will guarantee disappointment on your part.
> :
> : Pete
> :
> :
>
> All said and done, I still consider the monthly ~$30 charge to be a user fee
> of sorts. You can call FSS on the radio or
> pay the fee and receive the same info. More convenient to use the GPS? Maybe
> for some...

It isn't the same information. There is no substitute for having all
data front of you, and not having to waste time trying to figure out
what you're about to fly into, praying that someone will answer you on
Flight Watch, and then having to rely on that person's interpretation of
the weather. There's just no comparison whatsoever.

And your notion of the XM subscription cost being a "user fee" is
ridiculous, as I've pointed out previously.



JKG

[Bob Noel]

In article >,
"Peter Duniho" > wrote:


> Visible satellite should not vary in brightness according to altitude. But
> infrared does. Perhaps the XM images are from the infrared satellite, as
> Casey suggests.

hmmm. Looking at sat pictures from http://adds.aviationweather.gov/satellite/,
the visible sat picture sure seems like the brightness varies with altitude,
if only because the higher clouds can catch more sunlight.

But the B&W infrared images don't seem as good at showing low clouds
as the visible sat images.

The color infrared and the water vapor images are definitely better
at showing lower clouds.

--
Bob Noel
Looking for a sig the
lawyers will hate

[Jay Honeck]

> What is Atlas' tail number again? I might be coming your way next month.

No need for it, but here it is:

We'll look forward to your (potential) visit!

:-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Jay Honeck]

> Sounds a little bit like you were expecting the 496 to be a panacea for
> all things weather and it turns out to be just a system of displaying
> information you could get from other sources.

This is true to some degree. I had hoped that the airport information
from AWOS's and ASOS's would update at the same rate as the NEXRAD
(every 6 - 10 minutes), rather than just once per hour -- but I never
really inquired about this, so I have only myself to blame.

The main purpose for purchasing the unit -- weather avoidance and
awareness -- is still 100% valid when it comes to precip and convective
activity. I'm just not going to be able to use XM to avoid skanky
visibilities or ceilings, as I had hoped.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Casey Wilson[_1_]]

"Bob Noel" > wrote in message
news:ihatessppaamm-
> hmmm. Looking at sat pictures from
> http://adds.aviationweather.gov/satellite/,
> the visible sat picture sure seems like the brightness varies with
> altitude,
> if only because the higher clouds can catch more sunlight.
>
> But the B&W infrared images don't seem as good at showing low clouds
> as the visible sat images.
>
> The color infrared and the water vapor images are definitely better
> at showing lower clouds.
>
> --
> Bob Noel
> Looking for a sig the
> lawyers will hate

Hmmmm, first, you are not going to see any clouds or water vapor with
the infrared -- they are transparent to the photon energy being emitted by
the stuff below.
Second, any color other than a shade of grey in an infrared image is a
false color assigned to a discrete slice of the grey range. While the true
grey range may be 2**8, the false color range will (usually) only be 2**3.
The only reason to use false color is that the eye discerns adjacent 2**3
colors easier than 2**8 shades of grey.
Which brings up a third point. When you see varying color overlays --
like red for the center of a cell, then expanding out to orange, yellow and
eventually green -- it is unlikely they are infrared images. The infrared
image is derived by apparent differences in temperature. In a typical
rainstorm, the temperatures are close to equilibrium.

It is time now for me to waffle a bit. Sure as the sun came up this
morning, somebody will find a paper contradicting me. So, I confess, clouds
and water vapor are not 100% transparent to LWIR. But (there's always a big
butt), the emissivity is so low, it can't be detected with the relatively
crude instruments in the satellites as compared to a high-resolution, FFT
based, infrared spectrometer in a laboratory.

[Morgans[_3_]]

I figured you wuld be a good person to ask, so here goes.

I'm heading to Washington, (by car) and am going to be staying at a Regan
airport hotel.

What is the best way to get from there to Udvar-Hazy Annex? Is there a
shuttle, or train, or something?
--
Jim in NC

[Andrew Sarangan[_1_]]

Taken from the Miriam-Wester:
tactical: made or carried out with only a limited or immediate end in
view
strategy: a careful plan or method

So, if you are maneuvering around inidividual cells looking only a few
miles ahead, you are flying tactically. If you are looking at a larger
picture, devise a careful plan and deviate around the entire weather
front you are flying stretegically.




Jonathan Goodish wrote:
> In article >,
> Ron Natalie > wrote:
> > >> Nexrad XM datalink...is a strategic tool, not a
> > >> tactical tool.
> > >
> > > That is the conventional wisdom, but I suspect it comes more from lawyers
> > > than from pilots experienced with using datalinked NEXRAD.
> >
> > I used the same wording and I have XM weather and have used it.
>
> I believe you're not an instrument pilot? I suspect you use it quite
> differently than Dan, or other instrument pilots who are often engaged
> in weather flying.
>
> That being said, I certainly wouldn't rely on NEXRAD alone to weave my
> way through a line of cells. NEXRAD + Echo Tops + Sferics would get me
> closer, but I'm not sure that I'd take the risk of close-in deviations
> without the live picture (sferics + airborne radar).
>
>
>
>
>
> > > I use XM NEXRAD tactically all the time. If there's a growing cell 15
> > > miles
> > > ahead, I will use the NEXRAD picture to decide whether to go left or right
> > > around it based on its history and the location of other cells beyond it.
> > > That's tactical, to me, and it's the best thing about having satellite
> > > weather aboard.
> > >
> >
> > That's strategy not tactics.
>
> Making enroute decisions to deviate based on uplinked information?
> Sounds like tactics to me.
>
>
>
>
>
> JKG

[Peter Duniho]

"Bob Noel" > wrote in message
...
> hmmm. Looking at sat pictures from
> http://adds.aviationweather.gov/satellite/,
> the visible sat picture sure seems like the brightness varies with
> altitude,
> if only because the higher clouds can catch more sunlight.

It's nighttime in the US right now, so I can't really see what you're
talking about. Maybe you could copy an image you think illustrates your
point (during the daytime, of course) and post it somewhere so we're on the
same page.

The only thing that might allow "higher clouds to catch more sunlight" is if
the lower clouds are being shaded by some other higher clouds. Absent some
occlusion, it's not like there's "more sun" at higher altitudes. Near
sunset or sunrise, higher clouds will be brighter, but it's not a gradual
thing...it's just a matter of where the Earth's shadow falls on the cloud
layers, and the effect is very transient (lasting minutes for any given
area).

Pete

[Peter Duniho]

"Casey Wilson" <N2310D @ gmail.com> wrote in message
news:TSTBg.10080$l95.2392@trnddc08...
> Hmmmm, first, you are not going to see any clouds or water vapor with
> the infrared -- they are transparent to the photon energy being emitted by
> the stuff below.

You've written this twice, and I still don't believe it (with respect to
clouds). I see non-rain clouds in infrared satellite images all the time.
Right this moment, looking at the Northwest area radar images, I see a large
cell of light rain in the Yakima area, a smaller cell of light rain near
Hood River, and basically nothing else. Yet, on the infrared satellite
image, clouds obscure the entire middle third of the southern half of
Washington, the entire northwest corner of Oregon, with some spottier areas
in the northeast and southwest corners of Oregon. MUCH broader areas than
are shown on the radar.

This is just one example, but it is consistent with dozens of other
observations of the infrared satellite image (there'd probably be more, but
frankly I don't use that imagery very often anyway, so I don't bother to
look at it very much).

Note that ADDS presents an 11 micron wavelength infrared image, smack in the
range you claim won't show clouds. ADDS also specifically says that the 11
micron wavelength image shows clouds, just as the images there appear to do.

I'm curious if you have any reliable reference that supports the statement
that infrared in the 8-12 micron wavelength range will not show clouds. On
the face of it, the statement appears to be incorrect. I can believe that
*some* particularly thin clouds may not be visible in infrared images, but
it's clear to me that a general statement that clouds don't show up is
wrong. I see clouds on the infrared all the time.

Pete

[Frank Ch. Eigler]

> > hmmm. Looking at sat pictures from
> > http://adds.aviationweather.gov/satellite/,
> > the visible sat picture sure seems like the brightness varies with
> > altitude, if only because the higher clouds can catch more
> > sunlight.

It seems some people are missing the point of the IR images. The
color/brightness corresponds to cloud *temperature*, which is a
function of their *altitude*. So, beyond simply indicating cloud
coverage, they encode cloud top heights.

- FChE

[Dan Luke]

"Jay Honeck" wrote:

> skanky visibilities or ceilings

That is the main reason I got the I-rating. I got tired of sweating this
stuff out.

We left OSH VFR knowing that our first fuel stop was iffy. When we got
there, sure enough there was a cloud deck for at least 50 miles in every
direction.

Problem? No; requested a local IFR clearance from Approach, flew the
localizer approach to get under the deck, filed IFR while they were fueling
the plane and got back out above the deck and on our way home. Absolutely no
sweat.

I know it's a pain to get, but the rating is a great investment in future
pain avoidance.

--
Dan
C-172RG at BFM

[Jonathan Goodish]

Thanks for supporting my point.


JKG


In article . com>,
"Andrew Sarangan" > wrote:

> Taken from the Miriam-Wester:
> tactical: made or carried out with only a limited or immediate end in
> view
> strategy: a careful plan or method
>
> So, if you are maneuvering around inidividual cells looking only a few
> miles ahead, you are flying tactically. If you are looking at a larger
> picture, devise a careful plan and deviate around the entire weather
> front you are flying stretegically.
>
>
>
>
> Jonathan Goodish wrote:
> > In article >,
> > Ron Natalie > wrote:
> > > >> Nexrad XM datalink...is a strategic tool, not a
> > > >> tactical tool.
> > > >
> > > > That is the conventional wisdom, but I suspect it comes more from
> > > > lawyers
> > > > than from pilots experienced with using datalinked NEXRAD.
> > >
> > > I used the same wording and I have XM weather and have used it.
> >
> > I believe you're not an instrument pilot? I suspect you use it quite
> > differently than Dan, or other instrument pilots who are often engaged
> > in weather flying.
> >
> > That being said, I certainly wouldn't rely on NEXRAD alone to weave my
> > way through a line of cells. NEXRAD + Echo Tops + Sferics would get me
> > closer, but I'm not sure that I'd take the risk of close-in deviations
> > without the live picture (sferics + airborne radar).
> >
> >
> >
> >
> >
> > > > I use XM NEXRAD tactically all the time. If there's a growing cell 15
> > > > miles
> > > > ahead, I will use the NEXRAD picture to decide whether to go left or
> > > > right
> > > > around it based on its history and the location of other cells beyond
> > > > it.
> > > > That's tactical, to me, and it's the best thing about having satellite
> > > > weather aboard.
> > > >
> > >
> > > That's strategy not tactics.
> >
> > Making enroute decisions to deviate based on uplinked information?
> > Sounds like tactics to me.
> >
> >
> >
> >
> >
> > JKG

[Kyle Boatright]

".Blueskies." > wrote in message
. ..
>
> "Ron Natalie" > wrote in message
> m...
> : .Blueskies. wrote:
> : > "Peter Duniho" > wrote in message
> ...
> : >
<<<snip>>
> : >
> : I dunno, I have much better luck loading weather on the MX20 than
> : I have communicating with Flight Watch/FSS over the radio. And
> : the graphical presentation is much easier.
>
> I agree about the graphical representation... picture says a thousand
> words...

Agreed totally. Especially when I'm flying in an unfamiliar area, I have to
work very hard to translate much of the information (particulary weather
boundaries) the FSS is giving out into something useful for me.

FSS:"We have convective activity from the middle of nowhere, stretching
northwest to an abyss on the other side of nowhere".

Me: "I'm unfamiliar with the area, can you give me another point of
reference, like a major city".

In the end, it all works out, but it takes a lot longer than necessary. For
instance, on the way to Oshkosh a couple of weeks ago, I was trying to work
around some convective activity in the South Indiana/Illinois/North Kentucky
area. I asked the FSS for the southwestern extent of the convective stuff
and they gave me the name of a small town in (I think) Illinois. A little
back and forth ensued along with lots of map folding, unfolding, and
searching. Eventually, I asked them to relate the weather to Evansville and
they said the SW corner of the weather was 50 miles North of Evansville. I
understood that and was on my way. A picture would have made things so much
easier...

KB

[Casey Wilson[_1_]]

"Peter Duniho" > wrote in message
...
> "Casey Wilson" <N2310D @ gmail.com> wrote in message
> news:TSTBg.10080$l95.2392@trnddc08...
>> Hmmmm, first, you are not going to see any clouds or water vapor with
>> the infrared -- they are transparent to the photon energy being emitted
>> by the stuff below.
>
> You've written this twice, and I still don't believe it (with respect to
> clouds). I see non-rain clouds in infrared satellite images all the time.
> Right this moment, looking at the Northwest area radar images, I see a
> large cell of light rain in the Yakima area, a smaller cell of light rain
> near Hood River, and basically nothing else. Yet, on the infrared
> satellite image, clouds obscure the entire middle third of the southern
> half of Washington, the entire northwest corner of Oregon, with some
> spottier areas in the northeast and southwest corners of Oregon. MUCH
> broader areas than are shown on the radar.
>
> This is just one example, but it is consistent with dozens of other
> observations of the infrared satellite image (there'd probably be more,
> but frankly I don't use that imagery very often anyway, so I don't bother
> to look at it very much).
>
> Note that ADDS presents an 11 micron wavelength infrared image, smack in
> the range you claim won't show clouds. ADDS also specifically says that
> the 11 micron wavelength image shows clouds, just as the images there
> appear to do.
>
> I'm curious if you have any reliable reference that supports the statement
> that infrared in the 8-12 micron wavelength range will not show clouds.
> On the face of it, the statement appears to be incorrect. I can believe
> that *some* particularly thin clouds may not be visible in infrared
> images, but it's clear to me that a general statement that clouds don't
> show up is wrong. I see clouds on the infrared all the time.
>
> Pete

I'm sure you'll especially like this one, Pete, since figure (2) would seem
to uphold your aside of the discussion:

(a) ams.confex.com/ams/pdfpapers/98919.pdf



However, you must also go to:

(b) http://en.wikipedia.org/wiki/Cirrus_cloud

then venture back to example (a) above and go down to figure (5).



I will concede that cirrus are considered clouds but on the other hand
defend my position by saying they are not true clouds but masses of ice
crystals and my argument is based on the "true" cloud being visible water
vapor. I contend my argument fits both examples and does not contradict my
earlier statements.



Additionally, cirrus "clouds" (sic) are not the meddlesome phenoms that
create hazards to flying -- ever.

[Jose[_1_]]

> and my argument is based on the "true" cloud being visible water
> vapor.

Clouds are not "visible water vapor". Water vapor is invisible, and if
the water stayed as vapor, there would be no clouds. Clouds are
=condensed= water vapor, that is, liquid water droplets, or solid ice
particles, in such density as they impede light.

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.

[Peter Duniho]

"Casey Wilson" <N2310D @ gmail.com> wrote in message
news:31cCg.71541$Lh4.25482@trnddc02...
> [...]
> I will concede that cirrus are considered clouds but on the other hand
> defend my position by saying they are not true clouds but masses of ice
> crystals and my argument is based on the "true" cloud being visible water
> vapor. I contend my argument fits both examples and does not contradict my
> earlier statements.
> [...]

Your reply doesn't make any sense to me. In addition to the specific
statements within the reply being disjointed and without context, even what
is apparently comprehensible doesn't seem to be relevant to this discussion.

I wasn't talking about cirrus clouds. I'm talking about regular cloud
clouds, the kind we pilots worry about on a regular basis.

I'm not saying that cirrus clouds show up on infrared, I'm saying that
regular low- and middle-level clouds show up on infrared.

As far as your references go, you posted a link to a 20-page, single-spaced,
small-print document. If there's something in there that you think is
relevant, please feel free to quote it. The Wikipedia cirrus clouds
reference doesn't appear to be relevant at all, since I'm not talking about
cirrus clouds.

Try again?

Pete

p.s. It's cloudy here in the Pacific Northwest right now. No rain to speak
of anywhere near here. Satellite imagery shows our clouds just as I'd
expect...they are relatively dark in the picture, indicating that they are
lower-level clouds, which is consistent with the actual clouds I see.

[Casey Wilson[_1_]]

"Jose" > wrote in message
t...
>> and my argument is based on the "true" cloud being visible water vapor.
>
> Clouds are not "visible water vapor". Water vapor is invisible, and if
> the water stayed as vapor, there would be no clouds. Clouds are
> =condensed= water vapor, that is, liquid water droplets, or solid ice
> particles, in such density as they impede light.
>
> Jose

Picky, picky

[Dan Luke]

"Casey Wilson" <N2310D @ gmail.com> wrote:

>>> and my argument is based on the "true" cloud being visible water vapor.
>>
>> Clouds are not "visible water vapor". Water vapor is invisible, and if
>> the water stayed as vapor, there would be no clouds. Clouds are
>> =condensed= water vapor, that is, liquid water droplets, or solid ice
>> particles, in such density as they impede light.
>>
>> Jose
>
> Picky, picky

What's picky about it? Calling clouds "vapor" is the same order-of-magnitude
mistake as calling ice cubes "liquid."

--
Dan
C-172RG at BFM

[Matt Whiting]

Dan Luke wrote:
> "Casey Wilson" <N2310D @ gmail.com> wrote:
>
>
>>>> and my argument is based on the "true" cloud being visible water vapor.
>>>
>>>Clouds are not "visible water vapor". Water vapor is invisible, and if
>>>the water stayed as vapor, there would be no clouds. Clouds are
>>>=condensed= water vapor, that is, liquid water droplets, or solid ice
>>>particles, in such density as they impede light.
>>>
>>>Jose
>>
>>Picky, picky
>
>
> What's picky about it? Calling clouds "vapor" is the same order-of-magnitude
> mistake as calling ice cubes "liquid."
>

I don't see this definition implying invisibility at all, quite the
opposite if it "impairs transparency", then it isn't invisible.

http://www.meriam-webster.com/dictionary/vapor

Matt

[Jose[_1_]]

> I don't see this definition implying invisibility at all, quite the opposite if it "impairs transparency", then it isn't invisible.
>
> http://www.meriam-webster.com/dictionary/vapor

There are four definitions there, the fourth obviously does not apply.
The third is certainly invisible, but it doesn't apply either. The
second ("a substance in the gaseous state...") is the one that applies
here. The word "vapor" itself, even in this definition, does not mean
"an invisible substance", however, water vapor (gaseous water) is
invisible in macrosocopic amounts. While it is visible in megascopic
amounts, (a planet made entirely of water vapor would not be invisible),
that's more water vapor than what we fly in.

The first definition "diffused matter, (as smoke or fog)", since it is
found in the dictionary, is a definition that was meant at least once.
I am surprised that it is the first entry; in fact I think this says a
lot for the state of science education in this country. In a technical
discussion (such as a piloting newsgroup) and referring to the makeup of
clouds, I would find the first entry to be inappropriate, and the second
one is the definittion I would expect a speaker or writer would mean in
this context.

But if it's on the computer, it must be right. :)

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.

[.Blueskies.]

"Jonathan Goodish" > wrote in message
...
: In article >,
: ".Blueskies." > wrote:
: > : As I already said, all that XM does for you is show you the data in a
: > : friendlier way, and avoid the radio call to the FSS. Expecting more from
: > : them is unreasonable and will guarantee disappointment on your part.
: > :
: > : Pete
: > :
: > :
: >
: > All said and done, I still consider the monthly ~$30 charge to be a user fee
: > of sorts. You can call FSS on the radio or
: > pay the fee and receive the same info. More convenient to use the GPS? Maybe
: > for some...
:
: It isn't the same information. There is no substitute for having all
: data front of you, and not having to waste time trying to figure out
: what you're about to fly into, praying that someone will answer you on
: Flight Watch, and then having to rely on that person's interpretation of
: the weather. There's just no comparison whatsoever.
:
: And your notion of the XM subscription cost being a "user fee" is
: ridiculous, as I've pointed out previously.
:
:
:
: JKG

Taken out of context I see your confusion. The data that is the same is the METAR and other text based info that is
available via XM. The painted radar stuff is the thousand word picture.

Also, if you are just now "trying to figure out what you're about to fly into, praying that someone will answer you on
Flight Watch", you did a poor job on your preflight and other decisions up to that point.

Ridiculous maybe, but not much different from the FAA wanting to charge for a flight plan or a weather briefing - the
data is already generated and crunched by the gov't, and it is being delivered for a fee. You are a user, and you are
paying...

Dan D.

[.Blueskies.]

"Jonathan Goodish" > wrote in message
...
: In article . com>,
: "Jay Honeck" > wrote:
: > Obviously, in changing flight conditions this slow rate of change is
: > simply unacceptable, and we quickly reverted to listening to AWOS's
: > ahead on the radio.
: >
: > Strike two for XM.
:
: I suspect that the METAR data was being updated as expected, but the
: METARs don't change but once an hour, unless there's a SPECI issued.
: Same data as is available from flight service or DUATS.
:
:
:
: JKG

I see you get it now...

[Peter Duniho]

".Blueskies." > wrote in message
m...
> Taken out of context I see your confusion. The data that is the same is
> the METAR and other text based info that is
> available via XM. The painted radar stuff is the thousand word picture.

Yes, it is. Though, even the other data is presented more conveniently,
which is worth perhaps at least 100 words. It's superior to having to call
someone on the radio and have them relay the information verbally. The
radar image is invaluable.

> Also, if you are just now "trying to figure out what you're about to fly
> into, praying that someone will answer you on
> Flight Watch", you did a poor job on your preflight and other decisions up
> to that point.

IMHO, that's an unfair assumption. A pilot can do everything by the book,
with complete due diligence, and still wind up in that situation.

For example, on one flight I made across the country, one leg from Fort
Collins, CO to Springfield, MO involved a significant FSS-involved detour.
There had been no mention of convective activity when I got my pre-departure
briefing. But by the time I was enroute, I could clearly see a large mass
of clouds ahead, a couple of hours or so out of Springfield. I called up
the FSS and discovered a convective cell had popped up, and a fairly large
one at that. Fortunately, I got in touch with the FSS early enough that the
deviation required was minor (I only had to adjust course by 20 degrees or
so to safely bypass the convection).

It was still somewhat of a close one...the cell was moving east, catching up
to me at Springfield. I had to keep the fuel stop short and get back in the
air, otherwise I would have been engulfed and grounded until it passed. The
cell itself was quite large...at least 100 miles across, with lots of heavy
rain and other thunderstorm goings-on.

I admit, I wasn't exactly "praying" for the FSS to answer me on the radio,
but it certainly could have been a more stressful situation if I hadn't been
able to get in touch with them promptly (and that is sometimes the case,
when they are busy).

> Ridiculous maybe, but not much different from the FAA wanting to charge
> for a flight plan or a weather briefing - the
> data is already generated and crunched by the gov't, and it is being
> delivered for a fee. You are a user, and you are
> paying...

The fee proposed to be charged by the government in these cases is not
necessarily for the data itself. It seems to me that what the pro-user-fee
people are claiming is that it's the human involvement to receive, activate,
monitor, close, and initiate search & rescue if necessary that costs money.
The flight plan itself is actually constructed by the pilot, so it doesn't
make any sense to claim that the FAA is charging for the data in that case.
The "data", such as it is was compiled by the pilot, not the FAA, and if all
that the pilot needed was the data, they would not need to actually file the
flight plan at all.

Likewise the weather briefing. Yes, the data is already generated. The fee
is to cover the cost of providing a briefer to provide and interpret the
data to the pilot. I can't guarantee that a fee wouldn't be charged for an
entirely automated briefing (ie DUAT), but it's clear to me that the
user-fee folks are using the human-powered component as justification for
the fee.

All that aside, I don't really have any problem at all with you calling
these costs "user fees", so long as you are willing to be consistent. As I
mentioned before, we already pay for a variety of data compiled by the
government. Are these costs user fees? Is it a user fee when I purchase an
aviation chart or approach plates? By your estimation, that's what they
ought to be called.

If you're happy calling those things "user fees" as well, then more power to
you. I don't agree, but it's just semantics and frankly I don't find that a
useful debate. But at the very least, you need to stay consistent in order
for your viewpoint to have any validity.

Pete

[Jose[_1_]]

> Is it a user fee when I purchase an
> aviation chart or approach plates?

IF it were illegal to reuse charts, yes. But it's not. So no.

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.

[Jonathan Goodish]

In article >,
".Blueskies." > wrote:

> "Jonathan Goodish" > wrote in message
> ...
> : In article . com>,
> : "Jay Honeck" > wrote:
> : > Obviously, in changing flight conditions this slow rate of change is
> : > simply unacceptable, and we quickly reverted to listening to AWOS's
> : > ahead on the radio.
> : >
> : > Strike two for XM.
> :
> : I suspect that the METAR data was being updated as expected, but the
> : METARs don't change but once an hour, unless there's a SPECI issued.
> : Same data as is available from flight service or DUATS.
> :
> :
> :
> : JKG
>
> I see you get it now...

Excuse me? I see that you still don't.


JKG

[Jonathan Goodish]

In article >,
".Blueskies." > wrote:
> : It isn't the same information. There is no substitute for having all
> : data front of you, and not having to waste time trying to figure out
> : what you're about to fly into, praying that someone will answer you on
> : Flight Watch, and then having to rely on that person's interpretation of
> : the weather. There's just no comparison whatsoever.
> :
> : And your notion of the XM subscription cost being a "user fee" is
> : ridiculous, as I've pointed out previously.
> :
> :
> :
> : JKG
>
> Taken out of context I see your confusion. The data that is the same is the
> METAR and other text based info that is
> available via XM. The painted radar stuff is the thousand word picture.

I've flown many years without weather uplink, then with a StrikeFinder,
and now with a StrikeFinder and weather uplink. I may be confused about
many things, but the value of weather uplink isn't one of them.



> Also, if you are just now "trying to figure out what you're about to fly
> into, praying that someone will answer you on
> Flight Watch", you did a poor job on your preflight and other decisions up to
> that point.

So the weather picture doesn't change between the preflight planning and
the arrival at your destination?

The reality is that the weather picture has changed before you even
leave the flight briefing computer, or by the time or FSS briefing is
completed. It has certainly changed by the time that you're ready to
depart. Without weather uplink (or continuous updates from Flight
Watch), you have no idea HOW it's changed.




>
> Ridiculous maybe, but not much different from the FAA wanting to charge for a
> flight plan or a weather briefing - the
> data is already generated and crunched by the gov't, and it is being
> delivered for a fee. You are a user, and you are
> paying...

No. The data is gathered by NWS and private sites, and is processed by
Baron Services. It's Baron's algorithms, forecasts, etc. that go into
the products. I suspect that most of the $30 or $50 per month goes to
Baron and not XM, for Baron is a private weather provider (not unlike
AccuWeather, Weather Channel, WSI, etc.)

Information such as lightning strikes is 100% private, as the government
doesn't operate a lightning detection network.

In any case, it's not like charging for filing a flight plan because you
don't have to buy it to fly in the system. Since you seem to feel that
weather uplink has little value, it should impact you even less. Having
to pay for flight plans, or to use ATC services, would have a noticeable
impact everyone. Not so with weather uplink.



JKG

[Peter Duniho]

"Jose" > wrote in message
t...
>> Is it a user fee when I purchase an aviation chart or approach plates?
>
> IF it were illegal to reuse charts, yes. But it's not. So no.

What does that have to do with whether it's a user fee or not? Anyway, it's
certainly illegal to not be familiar with the current charts and airport
information. You can reuse old charts, but you ARE responsible for being
aware of the information on the current ones.

Besides, it's not illegal to not use XM weather. I appreciate it if you're
agreeing with my point, but I find that much less interesting than a valid
but opposing viewpoint.

Do you have a valid but opposing viewpoint? If so, I can't see it.

Pete

[Ron Natalie]

Kyle Boatright wrote:

>
> FSS:"We have convective activity from the middle of nowhere, stretching
> northwest to an abyss on the other side of nowhere".
>

The ones I love are the six minute missives that go something like

"We have a general area of activity *static* from just north of
*static* to *static* level 5 *static* ...

[Jose[_1_]]

>>>Is it a user fee when I purchase an aviation chart or approach plates?
>> IF it were illegal to reuse charts, yes. But it's not. So no.
> What does that have to do with whether it's a user fee or not?

Call it what you wish; what you call it is more semantics than anything
else. The difference I am bringing up is that when you purchase a
chart, you are not purchasing "the right to use the chart for a
specified time". It is like purchasing a book. You can read it any
time you want, you can lend it out, you can share it with friends. If
you download a tune on some services, you are most emphatically =not=
allowed to listen to it anywhere you want. You may not share it with
friends, and after you've played it a certain number of times, it
evaporates. You are paying for the "use" of the tune, but you are
paying for the =book= itself.

This is a non-trivial difference in the music world.

Something similar operates here simply due to the timeliness of the data
being used. A radar picture is not very useful a day later, so you
really are essentially paying for the =use= of the image. And,
impractical as it may be, you are probably not allowed to re-transmit
the data to the plane behind you. A similar issue exists with (say) the
Jepp subscription. You can hand your paper approach plates to another
pilot, who can use it in another plane. However, you can't do the same
with the subscription data in your GPS. And you can buy plates a state
at a time, but if you want to update your GPS, it's the whole country or
nothing. These are also non-trivial differences.

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.

[ET]

Jose > wrote in news:wFGCg.8331$uo6.3623
@newssvr13.news.prodigy.com:

> Call it what you wish; what you call it is more semantics than anything
> else. The difference I am bringing up is that when you purchase a
> chart, you are not purchasing "the right to use the chart for a
> specified time". It is like purchasing a book. You can read it any
> time you want, you can lend it out, you can share it with friends. If
> you download a tune on some services, you are most emphatically =not=
> allowed to listen to it anywhere you want. You may not share it with
> friends, and after you've played it a certain number of times, it
> evaporates. You are paying for the "use" of the tune, but you are
> paying for the =book= itself.
>

Your description of the music download senerio flies in the face of the
"fair use" doctrine.

--
-- ET >:-)

"A common mistake people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools."---- Douglas Adams

[Jose[_1_]]

> Your description of the music download senerio flies in the face of the
> "fair use" doctrine.

Maybe so. Wanna be the test case?

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.

[ET]

Jose > wrote in
m:

>> Your description of the music download senerio flies in the face of
>> the "fair use" doctrine.
>
> Maybe so. Wanna be the test case?
>
> Jose

I guarantee, if your interpretation was true, you would have seen many
many "test cases" in the media already. Every single, without an
exception, case in the media has been against people "holding out" or
"sharing" songs with the expectation that others will reciprocate. In
other words "swapping" or "bartering" songs. The headline may SAY
"illegal downloader sued" or some such, but when you read the article,
it's always an illegal "barterer".

If you find a case of someone being sued or prosecuted for "giving" a
cd(even a burned CD), or an ipod full of music to someone, I'd like to
know about it.

(Sorry about the OT deviation)

-- ET >:-)

"A common mistake people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools."---- Douglas Adams

[Jose[_1_]]

> Every single, without an
> exception, case in the media has been against people "holding out" or
> "sharing" songs with the expectation that others will reciprocate. In
> other words "swapping" or "bartering" songs.

But I can "swap" or "barter" books, CDs, and aviation charts. I can't
"swap" or "barter" songs or Jepp updates.

That is a significant difference. It is a difference I believe is
relevant to whether or not one might reasonably call something a "user fee".

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.

[Peter Duniho]

"Jose" > wrote in message
m...
> Call it what you wish; what you call it is more semantics than anything
> else.

I'm not the one proposing to call them user fees and I already pointed out
that this is purely a semantic question.

> The difference I am bringing up is that when you purchase a chart, you are
> not purchasing "the right to use the chart for a specified time".

You are, at least as much as you are purchasing the right to use weather
information for a specified time. That is, while you are permitted to keep
the chart, the chart is not useful for legally required purposes beyond a
certain time. Likewise, as far as I know there are no contractual
prohibitions against retaining the weather information provided by XM
weather...it's just that the data goes out of date, just as a chart goes out
of date.

> [...]
> Something similar operates here simply due to the timeliness of the data
> being used. A radar picture is not very useful a day later, so you really
> are essentially paying for the =use= of the image.

The radar and charts are equally time-limited in their usefulness, other
than the exact time period during which they are useful.

> And, impractical as it may be, you are probably not allowed to re-transmit
> the data to the plane behind you.

First of all, I'm not aware of any such prohibition. If you don't have
specific knowledge of one, I don't see how it's a relevant point.

> A similar issue exists with (say) the Jepp subscription. You can hand
> your paper approach plates to another pilot, who can use it in another
> plane. However, you can't do the same with the subscription data in your
> GPS.

Sure you can. You can pass a GPS receiver around just like you could
approach plates.

> And you can buy plates a state at a time, but if you want to update your
> GPS, it's the whole country or nothing. These are also non-trivial
> differences.

They are trivial differences. They pertain only to the specific
subscription model, and have nothing to do with the question of "user fees"
as that phrase has been applied to aviation products.

Pete

[Jose[_1_]]

> You can pass a GPS receiver around just like you could
> approach plates.

Not an installed one.

At least not without passing the entire plane around... which sort of
defeats the purpose.

> The radar and charts are equally time-limited in their usefulness, other
> than the exact time period during which they are useful.

This is non-trivial when it comes time to actually re-use them.

> [It has] nothing to do with the question of "user fees"
> as that phrase has been applied to aviation products.

You are right inasmuch as they differ from "FAA user fees", but if they
effectively accomplish the same thing, then it makes little difference
that an end run has been made around the dictionary.

Jose
--
The monkey turns the crank and thinks he's making the music.
for Email, make the obvious change in the address.

[ET]

Jose > wrote in
:

>> Every single, without an
>> exception, case in the media has been against people "holding out" or
>> "sharing" songs with the expectation that others will reciprocate.
>> In other words "swapping" or "bartering" songs.
>
> But I can "swap" or "barter" books, CDs, and aviation charts. I can't
> "swap" or "barter" songs or Jepp updates.
>
> That is a significant difference. It is a difference I believe is
> relevant to whether or not one might reasonably call something a "user
> fee".
>
> Jose

Sure you can, as long as the song or update you swaped was your only
copy.

But back to the original subject, it's a "convienience fee" leveled by
an individual company. For it to be a "user fee' in the same context of
"user fees" discussed by the FAA it would come from the gov't or a gov't
contractor.

--
-- ET >:-)

"A common mistake people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools."---- Douglas Adams