What can a PDA do for me?

[BJen]

I've got a late '80's model flight computer with an
integrated non-GPS final glide calculator and an IGC GPS
logger. I'm thinking about upgrade options to minimize the
mental workload for these items that I currently have
trouble with:

What's the current wind speed and direction?

What altitude do I need to final glide upwind to airport X
and turn back downwind to home at airport Y?

What airport is easiest to get to when I'm low given
different airport field elevations and current wind
direction.

When should I turn to get home 3 hours after I started this
task?

I'm not really sure what options I have. More generally,
I'm wondering what the PDA's can do. I presume they have no
airspeed/pitot input, no TE input and only GPS altitude.
Is that correct? Can they perform vario/TE/STF/final glide
functions?

I realize they can do GPS moving map, flight track
recording. I suspect they can figure wind from a circling
algorithm, but without TE or airspeed can they replace my
old flight computer? If not, can they supplement it (with
my GPS/pressure logger) so I can avoid the expense of a new
flight computer?

Anyone want to give me some comments here? Thanks.

[WilLiscomb]

go to:
http://www.winpilot.com



williscomb

[Andrew Warbrick]

Or go to:
http://www.seeyou.ws

At 14:12 14 April 2004, Williscomb wrote:
>go to:
> http://www.winpilot.com
>
>
>
>williscomb
>
>

[BJen]

I've been to both, but they are both trying to put the best
face on their products. No one says; We don't have any way
to connect to pitot, or TE probes, so the PDA does this or
can't do that. I see combinations of PDAs, varios, flight
computers, GPS units, IGC loggers, etc., but it's hard to
figure out what data they have coming in and what's doing
what.

Anyone else want to comment on the relationship between a
PDA vs a flight computer and what the PDA can do vs. what it
can't and why?


>Or go to:
>http://www.seeyou.ws
>
>>go to:
>> http://www.winpilot.com

[Jim Vincent]

Go here:

http://www.soarmn.com/cumulus/gn.htm

or here:

www.soaringpilot.com

or here:
http://www.ccsi.com/~inadas/



Jim Vincent
CFIG
N483SZ

[Brian Iten]

As far as I am concerned, my PDA is my verification
for the math I am doing in my head. I use Glide Navigator
II software linked to my Cambridge Model 20 and GPS-Nav
display. The PDA acts like a moving map and will give
you pretty close to exact distances to turnpoints,
airports and so on. It also tells me if I am with in
final glide to a safe landing area. It also comes in
handy while in thermals as it shows x's every few seconds
which can help you stay in a thermal or other forms
of lift.
Granted, I have a great deal of respect for the pilots
who were competing pre PDA's. The work loads during
a contest must have been insane at times.....
Also, the PDA is only as good as the equipment and
software you are using so do a lot of research. It
is also best to download as many of the programs to
demo them as possible. I also recommend speaking with
other pilots in your group about what they are using
and the pro's and con's that they have come across.
Best of luck,
Brian
17

[303pilot]

The one I've been using for a few years, CEGlide, can do all but the TAT
optimization--your last question. It may be able to do that w/the upgrade
now available, dunno.

I've found the final glide STF to be amazingly accurate, even w/out TE
input.

I'd recommend adding a handheld to your existing set-up for all the reasons
you mention.

Brent

"BJen" > wrote in message
...
> I've got a late '80's model flight computer with an
> integrated non-GPS final glide calculator and an IGC GPS
> logger. I'm thinking about upgrade options to minimize the
> mental workload for these items that I currently have
> trouble with:
>
> What's the current wind speed and direction?
>
> What altitude do I need to final glide upwind to airport X
> and turn back downwind to home at airport Y?
>
> What airport is easiest to get to when I'm low given
> different airport field elevations and current wind
> direction.
>
> When should I turn to get home 3 hours after I started this
> task?
>
> I'm not really sure what options I have. More generally,
> I'm wondering what the PDA's can do. I presume they have no
> airspeed/pitot input, no TE input and only GPS altitude.
> Is that correct? Can they perform vario/TE/STF/final glide
> functions?
>
> I realize they can do GPS moving map, flight track
> recording. I suspect they can figure wind from a circling
> algorithm, but without TE or airspeed can they replace my
> old flight computer? If not, can they supplement it (with
> my GPS/pressure logger) so I can avoid the expense of a new
> flight computer?
>
> Anyone want to give me some comments here? Thanks.

[Henryk Birecki]

What a PDA can do for you depends on how you interact with a computer.
Every program you would get will get you the necessary basic
information, so the most important part for you is the user interface.
You need to make your own decisions based on trying (or at least
looking at a program). A good place to start is
http://www.soaringpilotsoftware.com look for the GPS_LOG WinCE (it is
free) program, download version that runs on a PC and play with it to
see what it can do for you (oh and yes..., bring your brain with you
:) )
Remember also that PC user interface is always a different from that
on a PDA.

Henryk Birecki

BJen > wrote:

>I've got a late '80's model flight computer with an
>integrated non-GPS final glide calculator and an IGC GPS
>logger. I'm thinking about upgrade options to minimize the
>mental workload for these items that I currently have
>trouble with:
>............

[Hans L. Trautenberg]

It will kill you, if it requires to much attention to operate.

So carefully think about the features you need and then get one that
requires no attention during flight and that has an audio output.

Best Regards

Hans

[Paul Remde]

Hi,

I created a spreadsheet comparing several soaring flight computer and
software systems. I also created a presentation comparing soaring software
and flight computer systems. They are available as links on my Cumulus
homepage at: http://www.cumulus-soaring.com

My presentation segments the soaring instrument market into low cost (PDA
with GPS), medium cost (IGC Approved GPS/Logger), and high cost
(GPS/Logger/Vario/Speed-to-fly).

I put a lot of work into them. If you appreciate it, please consider buying
from me.

I sell Glide Navigator II and pocket*StrePla programs for Pocket PCs. They
are both very nice in their own way. I also sell Cambridge products.

I'll have to look into what pocket*StrePla offers in regard to using data
from a vario or GPS. Glide Navigator II can use wind data from either a
GPS-NAV/L-NAV combination or a 302. It uses the airspeed data for more
accurate wind information. It uses the pressure altitude data for accurate
altitude information.

All soaring Pocket PC software programs can calculate wind speed while
circling.

I'm pretty sure they can all calculate final glide around multiple
turnpoints - taking wind speed and direction into account.

I believe pocket*StrePla, SeeYou Mobile and WinPilot can display average
vario readings from some varios such as the Cambridge 302.

Another resource for example systems is my "Example Systems" page at:
http://www.cumulus-soaring.com/systems.htm

I hope the data is helpful.

Good Soaring,

Paul Remde
Cumulus Soaring Supplies

"BJen" > wrote in message
...
> I've been to both, but they are both trying to put the best
> face on their products. No one says; We don't have any way
> to connect to pitot, or TE probes, so the PDA does this or
> can't do that. I see combinations of PDAs, varios, flight
> computers, GPS units, IGC loggers, etc., but it's hard to
> figure out what data they have coming in and what's doing
> what.
>
> Anyone else want to comment on the relationship between a
> PDA vs a flight computer and what the PDA can do vs. what it
> can't and why?
>
>
> >Or go to:
> >http://www.seeyou.ws
> >
> >>go to:
> >> http://www.winpilot.com
>

[Rod]

Yeah, with most flight computers you spend too much time looking at the
screen or turning a knob to reach a menu, etc., while you should spend more
time looking outside. Most of the programs available for PDA's require no
more than a quick glance to get all the information you need.

Regards,
Rod

[Jim Phoenix]

I use a PDA (iPaq) and an SN-10 and I like the SN-10 because is has big
knobs and I hate poking at the PDA screen in flight with the stylus. If you
go with a PDA, set it up so you only need look at it during cruise, minimize
the finger-poking by programming the buttons on the unit. I NEVER have time
to mess with any of my instruments or even my radio knobs while thermaling -
for some reason I'm always been concentrating solely on climbing in the
core - I normally glance occasionally at whatever screen is up, but poke or
turn knobs? Not very successful with that unless I'm straight and level (or
close to it).

The lady I bought my Nimbus 3 from flew did her 1000km using a sectional
encased in two pieces of plexiglass with a string over the top tensioned by
a rubber band. It apparently worked very well for her - I've had no luck
tapping on it with my finger or even my iPaq stylus - damn thing doesn't
respond at all ;-)

Of course she flys farther in her 1-26 than I do in her old Nimbus...

Jim

"BJen" > wrote in message
...
> I've got a late '80's model flight computer with an
> integrated non-GPS final glide calculator and an IGC GPS
> logger. I'm thinking about upgrade options to minimize the
> mental workload for these items that I currently have
> trouble with:
>
> What's the current wind speed and direction?
>
> What altitude do I need to final glide upwind to airport X
> and turn back downwind to home at airport Y?
>
> What airport is easiest to get to when I'm low given
> different airport field elevations and current wind
> direction.
>
> When should I turn to get home 3 hours after I started this
> task?
>
> I'm not really sure what options I have. More generally,
> I'm wondering what the PDA's can do. I presume they have no
> airspeed/pitot input, no TE input and only GPS altitude.
> Is that correct? Can they perform vario/TE/STF/final glide
> functions?
>
> I realize they can do GPS moving map, flight track
> recording. I suspect they can figure wind from a circling
> algorithm, but without TE or airspeed can they replace my
> old flight computer? If not, can they supplement it (with
> my GPS/pressure logger) so I can avoid the expense of a new
> flight computer?
>
> Anyone want to give me some comments here? Thanks.

[BJen]

Thanks for the info Paul. It helps. Let me try to
summarize, and anyone who wants to chime in on where I'm
wrong, or right, feel free:

All PDAs connected to a GPS know location, ground speed and
track from the GPS. That lets them calculate wind speed and
direction from circling algorithms. There are some
straight line wind calculation algorithms used by flight
computers, but that requires an airspeed input, and since my
flight computer won't output any airspeed info to a PDA, I'd
have to buy one that does.

With wind and location data, a PDA can calculate altitude
required for final glide, glide to emergency fields and
glide around a TP before going home in wind. Presumably
this would have to be displayed as "altitude required"
unless it know current altitude somehow.

If the PDA knows altitude from an input, it can display
which fields you can reach, and whether you are high or low
on final glide. GPS altitude is relatively poor, but is one
option for getting current altitude info to the PDA. I
suppose you could input it manually, but that doesn't sound
practical. The best is a pressure sensor, but that would
mean getting altitude info from either a flight computer
(same as the airspeed problem above) or a Flight Recorder
that outputs its pressure altitude. Does the Volkslogger
give pressure alt to the PDA? Reading between the lines on
the PDA summaries I think it does.

For vario functions, it looks like it would need access to
TE. That's only available from a vario or flight computer.
I suppose it could fake it with altitude info for non-TE or
pseudo TE using wind and ground speed info. Do any do this?

For STF, it again needs TE from a vario or flight computer,
but I suppose it could fake it as above.

Does that sound right?


"Paul Remde" > wrote:

>Hi,
>
>I created a spreadsheet comparing several soaring flight computer and
>software systems. I also created a presentation comparing soaring software
>and flight computer systems. They are available as links on my Cumulus
>homepage at: http://www.cumulus-soaring.com
>
>My presentation segments the soaring instrument market into low cost (PDA
>with GPS), medium cost (IGC Approved GPS/Logger), and high cost
>(GPS/Logger/Vario/Speed-to-fly).
>
>I put a lot of work into them. If you appreciate it, please consider buying
>from me.
>
>I sell Glide Navigator II and pocket*StrePla programs for Pocket PCs. They
>are both very nice in their own way. I also sell Cambridge products.
>
>I'll have to look into what pocket*StrePla offers in regard to using data
>from a vario or GPS. Glide Navigator II can use wind data from either a
>GPS-NAV/L-NAV combination or a 302. It uses the airspeed data for more
>accurate wind information. It uses the pressure altitude data for accurate
>altitude information.
>
>All soaring Pocket PC software programs can calculate wind speed while
>circling.
>
>I'm pretty sure they can all calculate final glide around multiple
>turnpoints - taking wind speed and direction into account.
>
>I believe pocket*StrePla, SeeYou Mobile and WinPilot can display average
>vario readings from some varios such as the Cambridge 302.
>
>Another resource for example systems is my "Example Systems" page at:
>http://www.cumulus-soaring.com/systems.htm
>
>I hope the data is helpful.
>
>Good Soaring,
>
>Paul Remde
>Cumulus Soaring Supplies
>
>"BJen" > wrote in message
...
>> I've been to both, but they are both trying to put the best
>> face on their products. No one says; We don't have any way
>> to connect to pitot, or TE probes, so the PDA does this or
>> can't do that. I see combinations of PDAs, varios, flight
>> computers, GPS units, IGC loggers, etc., but it's hard to
>> figure out what data they have coming in and what's doing
>> what.
>>
>> Anyone else want to comment on the relationship between a
>> PDA vs a flight computer and what the PDA can do vs. what it
>> can't and why?
>>
>>
>> >Or go to:
>> >http://www.seeyou.ws
>> >
>> >>go to:
>> >> http://www.winpilot.com
>>
>

[Marc Ramsey]

BJen wrote:
> GPS altitude is relatively poor, but is one
> option for getting current altitude info to the PDA. I
> suppose you could input it manually, but that doesn't sound
> practical. The best is a pressure sensor, but that would
> mean getting altitude info from either a flight computer
> (same as the airspeed problem above) or a Flight Recorder
> that outputs its pressure altitude. Does the Volkslogger
> give pressure alt to the PDA? Reading between the lines on
> the PDA summaries I think it does.

GPS altitude is a more accurate indication of your actual (geometric)
altitude above sea level, so a lot of people use GPS altitude for final
glide, even if they have a flight computer or recorder that outputs
pressure altitude. Pressure altitude provides a more accurate short
term (a few minutes or less) indication of change in altitude.

BTW, some of the newer versions of PDA programs contain an internal map
of the ground elevation, so they can display your altitude above ground.
Some now figure your final glide altitude needed with consideration of
the ground elevations (i.e. mountains) between your current position and
the destination.

> For vario functions, it looks like it would need access to
> TE. That's only available from a vario or flight computer.
> I suppose it could fake it with altitude info for non-TE or
> pseudo TE using wind and ground speed info. Do any do this?

Using GPS altitude only, the climb rate averaged over 30 seconds or so
is fairly accurate most of the time. Some PDA programs do this, some
also try to account for total energy as you suggest, most calculate an
average thermal climb rate, which is usually quite accurate.

> For STF, it again needs TE from a vario or flight computer,
> but I suppose it could fake it as above.
>
> Does that sound right?

Yes.

Marc

[303pilot]

Check your assumptions on GPS altitude. In my experience, it is very
similar to pressure altitude and doesn't suffer from the problems of
pressure altitude. I believe GPS altitude to be as good or better than
pressure altitude for all practical purposes.
Re: STF I get very good STF info from my handheld. If it says to fly 80kts
around the last turnpoint and on home, I fly 80 and arrive home at pattern
altitude, just as programmed.

Brent
"BJen" > wrote in message
...
> glide around a TP before going home in wind. Presumably
> this would have to be displayed as "altitude required"
> unless it know current altitude somehow.
>
> If the PDA knows altitude from an input, it can display
> which fields you can reach, and whether you are high or low
> on final glide. GPS altitude is relatively poor, but is one
> option for getting current altitude info to the PDA. I
> suppose you could input it manually, but that doesn't sound
> practical. The best is a pressure sensor, but that would
> mean getting altitude info from either a flight computer
> (same as the airspeed problem above) or a Flight Recorder
> that outputs its pressure altitude. Does the Volkslogger
> give pressure alt to the PDA? Reading between the lines on
> the PDA summaries I think it does.
>
> For vario functions, it looks like it would need access to
> TE. That's only available from a vario or flight computer.
> I suppose it could fake it with altitude info for non-TE or
> pseudo TE using wind and ground speed info. Do any do this?
>
> For STF, it again needs TE from a vario or flight computer,
> but I suppose it could fake it as above.
>
> Does that sound right?

[Martin Gregorie]

On 15 Apr 2004 08:48:06 -0500, BJen >
wrote:

>Thanks for the info Paul. It helps. Let me try to
>summarize, and anyone who wants to chime in on where I'm
>wrong, or right, feel free:
>
>All PDAs connected to a GPS know location, ground speed and
>track from the GPS. That lets them calculate wind speed and
>direction from circling algorithms. There are some
>straight line wind calculation algorithms used by flight
>computers, but that requires an airspeed input, and since my
>flight computer won't output any airspeed info to a PDA, I'd
>have to buy one that does.
>
>With wind and location data, a PDA can calculate altitude
>required for final glide, glide to emergency fields and
>glide around a TP before going home in wind. Presumably
>this would have to be displayed as "altitude required"
>unless it know current altitude somehow.
>
>If the PDA knows altitude from an input, it can display
>which fields you can reach, and whether you are high or low
>on final glide. GPS altitude is relatively poor, but is one
>option for getting current altitude info to the PDA. I
>suppose you could input it manually, but that doesn't sound
>practical. The best is a pressure sensor, but that would
>mean getting altitude info from either a flight computer
>(same as the airspeed problem above) or a Flight Recorder
>that outputs its pressure altitude. Does the Volkslogger
>give pressure alt to the PDA? Reading between the lines on
>the PDA summaries I think it does.
>
>For vario functions, it looks like it would need access to
>TE. That's only available from a vario or flight computer.
>I suppose it could fake it with altitude info for non-TE or
>pseudo TE using wind and ground speed info. Do any do this?
>
You may be over-complicating things. The following assumes you prefer
cheap toys to expensive ones.

A simple GPS + PDA system can handle all your navigation and glide
calculations independently of the rest of your instruments. Granted,
the GPS altitude is less accurate than position, but probably still
good enough for FG calculations given all the other uncertainties and
happenstances during the final glide.

All you really need on top of that is a simple audio vario such as a
B.40, Tasman, or even an ancient Cambridge Mk 4. These are all
stand-alone instruments, so no additional interconnection is needed.

>For STF, it again needs TE from a vario or flight computer,
>but I suppose it could fake it as above.
>
If you have room for a second vario, fit a mechanical unit with a
Macready ring.

A club mate uses exactly this type of rig for club class competition
in his ASW-19.

===============

Why I think this is a good way to go
-------------------------------------------
For the last two seasons I flew my club's Pegase 90 with a Garmin GPS
II+, Cambridge Mk 4 audio vario, Winter vario w/MaCready ring and EW
model D logger. The only additional thing I would have liked was some
sort of moving map display to show airspace restrictions, etc.

This season I was planned to buy a glider and intended to install an
iPAQ 3630 running XCsoar, Garmin GPS 2+, Tasman or B.40, Winter
mechanical and the EW logger. However, I bought an ASW-20 which turned
out to have an SDI C4 already installed. In addition I installed my
GPS II+ and my EW logger. I'd previously acquired an iPAQ 3630 and am
thinking (slowly) about where to fit it so as to add the moving map
capability, but am short of panel real estate: the only really
suitable space is occupied by my GPS II+.

=========

If you need anything more complex than the GPS+PDA and separate varios
be aware that there are interconnect issues. In particular, a lot of
glide computers require the turn points to be fed to them from the GPS
but many? all? PDA programs don't accept turnpoints from the GPS, so
immediately you're into double task entry. My immediate thought was to
bypass this by using a blind GPS and put the task into the PDA:
however, most of the free-standing PDA programs don't output the
route-related GPS sentences needed by the SDI glide computer.

If you use the simple set-up I outlined above you'll avoid this sort
of nonsense and can, if you want, install a blind GPS to feed the PDA.
This is a good idea because the GPS doesn't then take up panel space
(it can be invisible behind a panel-top compass) or need any inputs,
freeing up panel space for the PDA. The other way to avoid
connectivity problems is to go with a complete set of kit from the
likes of Borgelt or Cambridge but that's more expensive.

Anything else is likely to result in the sort of connectivity issues I
described.

HTH
Martin

--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

[Janos Bauer]

I do agree with Martin. I use my PDA (Palm M515 with soaringpilot sw.)
as a short time averager (1-1.5 sec delay) also and it has GPS input
only.
I don't think anyone really follows speed to fly values so accurately
that it would worth to build such a complex system (feed PDA with TE).
At least for me it's enough to to know if I should slow down to 120km/h
ot push over 160km/h in a stdCirrus:)
Regards,

/Janos



Martin Gregorie wrote:

> You may be over-complicating things. The following assumes you prefer
> cheap toys to expensive ones.
>
> A simple GPS + PDA system can handle all your navigation and glide
> calculations independently of the rest of your instruments. Granted,
> the GPS altitude is less accurate than position, but probably still
> good enough for FG calculations given all the other uncertainties and
> happenstances during the final glide.
>
> All you really need on top of that is a simple audio vario such as a
> B.40, Tasman, or even an ancient Cambridge Mk 4. These are all
> stand-alone instruments, so no additional interconnection is needed.
>
> >For STF, it again needs TE from a vario or flight computer,
> >but I suppose it could fake it as above.
> >
> If you have room for a second vario, fit a mechanical unit with a
> Macready ring.
>
> A club mate uses exactly this type of rig for club class competition
> in his ASW-19.