Air traffic detection question

[FISHnFLY]

Has anyone flown with any of these new "portable tcas" devices? I
recently got a Monroy ATD-300, which is the lowest price, that gives
range and altitude, but have been very disappointed in the
performance. My experience is that the altitude and range of aircraft
it is reporting are constantly changing drastically.

[Darrel Toepfer]

FISHnFLY wrote:

> Has anyone flown with any of these new "portable tcas" devices? I
> recently got a Monroy ATD-300, which is the lowest price, that gives
> range and altitude, but have been very disappointed in the
> performance. My experience is that the altitude and range of aircraft
> it is reporting are constantly changing drastically.

Thats sad news, I've been interested in the purchase of that model,
mainly because of its "best deal" pricing as well...

[James M. Knox]

(FISHnFLY) wrote in
om:

> Has anyone flown with any of these new "portable tcas" devices? I
> recently got a Monroy ATD-300, which is the lowest price, that gives
> range and altitude, but have been very disappointed in the
> performance. My experience is that the altitude and range of aircraft
> it is reporting are constantly changing drastically.

I haven't had a chance yet to put an ATD-300 through it's paces, nor to
compare it to the latest new crop that have come out in the last few
months. I do have an ATD-200 in my plane and find it somewhere between
useful and toy. Toy, because it probably only identifies about 30% of
the traffic in a useful fashion (has a habit of not lighting up until
the traffic has passed <G>). Useful, because it sometimes does alert me
to look for traffic out in the boonies, when there hasn't been another
aircraft within 100 nm for the last 2 hours (hard to keep a good scan
going under those conditions). A large percentage of the time it gives
false alarms.

None of these are going to give you anything more than a very loose idea
of range. Any appearance of good range information is a lie -- a big
smoothing algorithm that makes it look like good data, but still may be
grossly inaccurate.

The older units did NOT do a real decode on altitude and hence might
trigger on a jet 30,000 feet above you, and fail to detect a '172 flying
200 feet below. The newer ones are supposed to pick up the transponder
altitude, but probably have trouble keeping it matched to the
appropriate target. [I develop algorithms for the military to track
airborne threat targets and it can get complicated.] Does it vary the
altitude substantially when you are pretty sure there is only one threat
nearby?



-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------

[Darrel Toepfer]

James M. Knox wrote:

> I haven't had a chance yet to put an ATD-300 through it's paces, nor to
> compare it to the latest new crop that have come out in the last few
> months. I do have an ATD-200 in my plane and find it somewhere between
> useful and toy. Toy, because it probably only identifies about 30% of
> the traffic in a useful fashion (has a habit of not lighting up until
> the traffic has passed <G>). Useful, because it sometimes does alert me
> to look for traffic out in the boonies, when there hasn't been another
> aircraft within 100 nm for the last 2 hours (hard to keep a good scan
> going under those conditions). A large percentage of the time it gives
> false alarms.

Are you using the included antenna or an external one?

I like the fact that the new model allows you to check your own
equipments ouputted signals...

> None of these are going to give you anything more than a very loose idea
> of range. Any appearance of good range information is a lie -- a big
> smoothing algorithm that makes it look like good data, but still may be
> grossly inaccurate.
>
> The older units did NOT do a real decode on altitude and hence might
> trigger on a jet 30,000 feet above you, and fail to detect a '172 flying
> 200 feet below. The newer ones are supposed to pick up the transponder
> altitude, but probably have trouble keeping it matched to the
> appropriate target. [I develop algorithms for the military to track
> airborne threat targets and it can get complicated.] Does it vary the
> altitude substantially when you are pretty sure there is only one threat
> nearby?

I'm sure the plane itself will always act as a shield, depending on
where the target aircraft might be located...

[CriticalMass]

James M. Knox wrote:

>I do have an ATD-200 in my plane and find it somewhere between
>useful and toy. Toy, because it probably only identifies about 30% of
>the traffic in a useful fashion (has a habit of not lighting up until
>the traffic has passed <G>). Useful, because it sometimes does alert me
>to look for traffic out in the boonies, when there hasn't been another
>aircraft within 100 nm for the last 2 hours (hard to keep a good scan
>going under those conditions). A large percentage of the time it gives
>false alarms.
>


That just about NAILS it for what mine does for me.

I'm starting to get curious about what the newer ones can do, but to act
on that curiosity, I need to sell my ATD-200.

If anyone's interested, email me. I'd sacrifice it for $250 plus shipping.

[FISHnFLY]

I couldn't speak for the 200 model to be honest with you. The model I
got is the ATD-300. I watched it closely for a while and it was very
hard to understand what it was tracking. The NM half would show
anywhere between 5 to 0 and the altitude would jump around a lot. At
times it would appear to be functioning correctly, but then it would
go back into a very random cycle of range and altitude. If I turn off
my transponder it appears to settle down a bit. It may be having a
hard time trying to hear my transponder, but I can't tell for sure.
At one point I watched a twin Cessna fly within a half mile of me and
about 200-400 feet above me, but the only thing I got on the display
was that it was somewhere between 4 miles and 0 miles and above me 100
feet, then it would report below me 300, then show *my* altitude with
no range. Most of the time the range would change from 4 or 5 miles
to 0-1 miles within 5 to maybe 10 seconds. I think the ATD-300 is the
lest expensive out there, doesn't appear to be very accurate in WHAT
it displays.


"James M. Knox" > wrote in message >...
> (FISHnFLY) wrote in
> om:
>[i]
> > Has anyone flown with any of these new "portable tcas" devices? I
> > recently got a Monroy ATD-300, which is the lowest price, that gives
> > range and altitude, but have been very disappointed in the
> > performance. My experience is that the altitude and range of aircraft
> > it is reporting are constantly changing drastically.
>
> I haven't had a chance yet to put an ATD-300 through it's paces, nor to
> compare it to the latest new crop that have come out in the last few
> months. I do have an ATD-200 in my plane and find it somewhere between
> useful and toy. Toy, because it probably only identifies about 30% of
> the traffic in a useful fashion (has a habit of not lighting up until
> the traffic has passed <G>). Useful, because it sometimes does alert me
> to look for traffic out in the boonies, when there hasn't been another
> aircraft within 100 nm for the last 2 hours (hard to keep a good scan
> going under those conditions). A large percentage of the time it gives
> false alarms.
>
> None of these are going to give you anything more than a very loose idea
> of range. Any appearance of good range information is a lie -- a big
> smoothing algorithm that makes it look like good data, but still may be
> grossly inaccurate.
>
> The older units did NOT do a real decode on altitude and hence might
> trigger on a jet 30,000 feet above you, and fail to detect a '172 flying
> 200 feet below. The newer ones are supposed to pick up the transponder
> altitude, but probably have trouble keeping it matched to the
> appropriate target. Does it vary the
> altitude substantially when you are pretty sure there is only one threat
> nearby?
>
>
>
> -----------------------------------------------
> James M. Knox
> TriSoft ph 512-385-0316
> 1109-A Shady Lane fax 512-366-4331
> Austin, Tx 78721
> -----------------------------------------------

[Brian Sponcil]

Indeed sad. I've been interested in an extra set of "eyes" ever since what
initially appeared to be a bird turned into a mooney faster than you can say
Ovation Dx. I can't tell you how many times I've watched planes fly by me
without a peep from flight following.

Anyone had experience with the SureCheck RX series transponder detectors?

I guess I'll have to just buck up and get a mode-s transponder w/MFD.


-Brian


"Darrel Toepfer" > wrote in message
.. .
> FISHnFLY wrote:
>
> > Has anyone flown with any of these new "portable tcas" devices? I
> > recently got a Monroy ATD-300, which is the lowest price, that gives
> > range and altitude, but have been very disappointed in the
> > performance. My experience is that the altitude and range of aircraft
> > it is reporting are constantly changing drastically.
>
> Thats sad news, I've been interested in the purchase of that model,
> mainly because of its "best deal" pricing as well...

[James M. Knox]

Darrel Toepfer > wrote in
:

> Are you using the included antenna or an external one?

I'm using the included antenna still. There is no doubt that a dual
(high-low) antenna would be a big help. However, I often see the threat
aircraft pass directly in front of my plane and nothing from the ATD
until it is well past. The ATD antenna had a clear view - so I suspect
the problem is more with shadowing of the transmitting antenna.
Unfortunately, there is nothing that can be done about this on the ATD-
equipped aircraft.

> I like the fact that the new model allows you to check your own
> equipments ouputted signals...

True. Even the ATD-200 had a light to alert you that you were
responding to a ping. And my GPS tells me what my xpndr encoder is
saying. That still leaves faults in the xpndr itself (transmitting
false information) but not a big problem.

> I'm sure the plane itself will always act as a shield, depending on
> where the target aircraft might be located...

True. I know aircraft with Skywatch installed, complete with the top
and bottom antennas. That's a $20K+ system, and still they see aircraft
"appear and disappear" in certain quadrants. Heck, even ATC (which
typically has a better geometry) will see aircraft drop the Mode-C when
the plane is turning, or when some other part of the plane intervenes.
That could be fixed with a more sophisticated xpndr system, but no one
is going to propose that much money to upgrade the entire fleet.

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------

[James M. Knox]

(FISHnFLY) wrote in
om:

> I couldn't speak for the 200 model to be honest with you. The model I
> got is the ATD-300. I watched it closely for a while and it was very
> hard to understand what it was tracking. The NM half would show
> anywhere between 5 to 0 and the altitude would jump around a lot.

Can you define "a lot"? The range problem is something I would expect.
But the altitude (if there is only one target anywhere near) should be
accurate. Having said that, both your altitude and that of the threat
aircraft can be jumping around by at least 100 feet (for a minimum
"jitter" of a couple of hundred feet).

So... Are you only seeing it "jump around a lot" +/- maybe 300 feet? Or is
the altitude readout REALLY varying massively?

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------

[Darrel Toepfer]

James M. Knox wrote:
> Darrel Toepfer wrote:
>
>>Are you using the included antenna or an external one?
>
> I'm using the included antenna still. There is no doubt that a dual
> (high-low) antenna would be a big help. However, I often see the threat
> aircraft pass directly in front of my plane and nothing from the ATD
> until it is well past. The ATD antenna had a clear view - so I suspect
> the problem is more with shadowing of the transmitting antenna.
> Unfortunately, there is nothing that can be done about this on the ATD-
> equipped aircraft.

But did they have a working transponder? <g>

Thanks for the reply...

[BHelman]

I have the vrx and have been very satisfied so far. The vrx has it's
own altimeter to back up my transponder's altitude, which probably
makes all the difference in accuracy. The traffic it reports is
usually right on the mark with what ATC reports, and has many times
pointed out aircraft I can see and vrx can see, but for some reason
ATC can not. It cost more obviously, but probably because it has the
technology to do the job right IMO. I think it is a much more
professional product overall in terms of accuracy and features.




"Brian Sponcil" > wrote in message >...
> Indeed sad. I've been interested in an extra set of "eyes" ever since what
> initially appeared to be a bird turned into a mooney faster than you can say
> Ovation Dx. I can't tell you how many times I've watched planes fly by me
> without a peep from flight following.
>
> Anyone had experience with the SureCheck RX series transponder detectors?
>
> I guess I'll have to just buck up and get a mode-s transponder w/MFD.
>
>
> -Brian
>
>
> "Darrel Toepfer" > wrote in message
> .. .
> > FISHnFLY wrote:
> >
> > > Has anyone flown with any of these new "portable tcas" devices? I
> > > recently got a Monroy ATD-300, which is the lowest price, that gives
> > > range and altitude, but have been very disappointed in the
> > > performance. My experience is that the altitude and range of aircraft
> > > it is reporting are constantly changing drastically.
> >
> > Thats sad news, I've been interested in the purchase of that model,
> > mainly because of its "best deal" pricing as well...

[Thierry]

Hello,
Sorry to jump into your exchange ... You may consider trying a Prox
alert R5 which monitors up to three threats simultaneously.

Don't ask me to elaborate online on other devices since i work for
Prox alert.

As we are an honest company we have no problem to offer a 30 days
money back
guarantee. www.prox alert.com (HQ in Phoenix AZ)

We will be happy to answer your technical questions about affordable
collision avoidance devices.

Thierry

(FISHnFLY) wrote in message >...
> I couldn't speak for the 200 model to be honest with you. The model I
> got is the ATD-300. I watched it closely for a while and it was very
> hard to understand what it was tracking. The NM half would show
> anywhere between 5 to 0 and the altitude would jump around a lot. At
> times it would appear to be functioning correctly, but then it would
> go back into a very random cycle of range and altitude. If I turn off
> my transponder it appears to settle down a bit. It may be having a
> hard time trying to hear my transponder, but I can't tell for sure.
> At one point I watched a twin Cessna fly within a half mile of me and
> about 200-400 feet above me, but the only thing I got on the display
> was that it was somewhere between 4 miles and 0 miles and above me 100
> feet, then it would report below me 300, then show *my* altitude with
> no range. Most of the time the range would change from 4 or 5 miles
> to 0-1 miles within 5 to maybe 10 seconds. I think the ATD-300 is the
> lest expensive out there, doesn't appear to be very accurate in WHAT
> it displays.
>
>
> "James M. Knox" > wrote in message >...
> > (FISHnFLY) wrote in
> > om:
> >[i]
> > > Has anyone flown with any of these new "portable tcas" devices? I
> > > recently got a Monroy ATD-300, which is the lowest price, that gives
> > > range and altitude, but have been very disappointed in the
> > > performance. My experience is that the altitude and range of aircraft
> > > it is reporting are constantly changing drastically.
> >
> > I haven't had a chance yet to put an ATD-300 through it's paces, nor to
> > compare it to the latest new crop that have come out in the last few
> > months. I do have an ATD-200 in my plane and find it somewhere between
> > useful and toy. Toy, because it probably only identifies about 30% of
> > the traffic in a useful fashion (has a habit of not lighting up until
> > the traffic has passed <G>). Useful, because it sometimes does alert me
> > to look for traffic out in the boonies, when there hasn't been another
> > aircraft within 100 nm for the last 2 hours (hard to keep a good scan
> > going under those conditions). A large percentage of the time it gives
> > false alarms.
> >
> > None of these are going to give you anything more than a very loose idea
> > of range. Any appearance of good range information is a lie -- a big
> > smoothing algorithm that makes it look like good data, but still may be
> > grossly inaccurate.
> >
> > The older units did NOT do a real decode on altitude and hence might
> > trigger on a jet 30,000 feet above you, and fail to detect a '172 flying
> > 200 feet below. The newer ones are supposed to pick up the transponder
> > altitude, but probably have trouble keeping it matched to the
> > appropriate target. Does it vary the
> > altitude substantially when you are pretty sure there is only one threat
> > nearby?
> >
> >
> >
> > -----------------------------------------------
> > James M. Knox
> > TriSoft ph 512-385-0316
> > 1109-A Shady Lane fax 512-366-4331
> > Austin, Tx 78721
> > -----------------------------------------------

[Darrel Toepfer]

Thierry wrote:

> Hello,
> Sorry to jump into your exchange ... You may consider trying a Prox
> alert R5 which monitors up to three threats simultaneously.
>
> Don't ask me to elaborate online on other devices since i work for
> Prox alert.
>
> As we are an honest company we have no problem to offer a 30 days
> money back guarantee. www.proxalert.com (HQ in Phoenix AZ)
>
> We will be happy to answer your technical questions about affordable
> collision avoidance devices.

Thierry, I like the target squawk code readout as well, but it comes
at more than double the price... Still alot cheaper than the $19k
units that are out there too... <G>

[FISHnFLY]

"A lot" being + 300 for about 1 seconds then - 600 for another half
second to +700 then it will stick for a while, only to go back to very
odd changes. If I read this right I would have had 60 aircraft around
me between 5 to 0 miles and one at just about every altitude.
Occasionally it will resort to showing what appears to be actual
altitude, but I can't tell for sure when it switches. My overall
opinion is that it doesn't seem to be able to "lock" onto any one
particular aircraft, but instead will swing between many, or be
misreading them all together. I flew with it again this evening and
it did basically the same thing, only this time I had a low wing piper
pass directly above me, not more than 100 to 200 feet, and it kept
telling me someone was way below me at "0 NM to 3 NM"

I am starting to think that the ATD-300 is still in a "beta-test"
mode, and perhaps not ready for prime time. I got one of these right
out of the release along with three other guys, and we have all had
about the same results. I am considering trying their competitor
trafficscope while I still have the ATD to see side by side for myself
how they compare in accuracy. I was going to get another competitor
called proxalrt into the ring as well, but the only place that carried
it said they don't keep it in stock.

We'll see.




"James M. Knox" > wrote in message >...
> (FISHnFLY) wrote in
> om:
>
> > I couldn't speak for the 200 model to be honest with you. The model I
> > got is the ATD-300. I watched it closely for a while and it was very
> > hard to understand what it was tracking. The NM half would show
> > anywhere between 5 to 0 and the altitude would jump around a lot.
>
> Can you define "a lot"? The range problem is something I would expect.
> But the altitude (if there is only one target anywhere near) should be
> accurate. Having said that, both your altitude and that of the threat
> aircraft can be jumping around by at least 100 feet (for a minimum
> "jitter" of a couple of hundred feet).
>
> So... Are you only seeing it "jump around a lot" +/- maybe 300 feet? Or is
> the altitude readout REALLY varying massively?
>
> -----------------------------------------------
> James M. Knox
> TriSoft ph 512-385-0316
> 1109-A Shady Lane fax 512-366-4331
> Austin, Tx 78721
> -----------------------------------------------

[James M. Knox]

Darrel Toepfer > wrote in
:

>> However, I often see the
>> threat aircraft pass directly in front of my plane and nothing from
>> the ATD until it is well past. The ATD antenna had a clear view - so
>
> But did they have a working transponder? <g>

Had to, or it wouldn't have picked them up at about a mile and just passed
my centerline. [Yes, if it only happened once in my lifetime, I would
think that maybe they say me, and that somehow made them realized they
hadn't turned their transponder on. But I have seen nearly identical
reactions on several occasions.]

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------

[James M. Knox]

(FISHnFLY) wrote in
om:

> "A lot" being + 300 for about 1 seconds then - 600 for another half
> second to +700 then it will stick for a while, only to go back to very
> odd changes. If I read this right I would have had 60 aircraft around
> me between 5 to 0 miles and one at just about every altitude.

Yeah, I'd call that "a lot". <G> It's certainly more than could be
accounted for by normal encoder "quantization" error.

Your guess about what may be happening sounds like a good possibility.
Having developed a lot of this software for the military, it *is* difficult
to keep multiple threat tracks identified uniquely. Of course, that is
with all the aircraft involved possibly undergoing high-G high speed
maneuvering. The ATD-300 has less sensor data available than I have in the
typical fighter aircraft, but the targets are also doing a LOT less
maneuvering.

> I am starting to think that the ATD-300 is still in a "beta-test"
> mode, and perhaps not ready for prime time.

The ATD-200 had similar problems, and a bunch of them had to be sent back
for "adjustment." They kept picking up the host aircraft as a threat.

[BHelman]

This could explain the behavior in regards to the altitude with the
Monroy unit, which does not use any altimeters.

http://www.surecheck.net/avionics/altimeter.html

I think it was the Ryan series of tcas that when first launched only
used altitude from the "host" transponder, rather than directly from
the encoder, and found it was not a 100% reliable way to get altitude.
The squawk code apparently is the major problem, and with no "second
opinion" from an additional altimeter, I can see how the Monroy unit
might get confused.



Re:

(FISHnFLY) wrote in message >...
> "A lot" being + 300 for about 1 seconds then - 600 for another half
> second to +700 then it will stick for a while, only to go back to very
> odd changes. If I read this right I would have had 60 aircraft around
> me between 5 to 0 miles and one at just about every altitude.
> Occasionally it will resort to showing what appears to be actual
> altitude, but I can't tell for sure when it switches. My overall
> opinion is that it doesn't seem to be able to "lock" onto any one
> particular aircraft, but instead will swing between many, or be
> misreading them all together. I flew with it again this evening and
> it did basically the same thing, only this time I had a low wing piper
> pass directly above me, not more than 100 to 200 feet, and it kept
> telling me someone was way below me at "0 NM to 3 NM"
>
> I am starting to think that the ATD-300 is still in a "beta-test"
> mode, and perhaps not ready for prime time. I got one of these right
> out of the release along with three other guys, and we have all had
> about the same results. I am considering trying their competitor
> trafficscope while I still have the ATD to see side by side for myself
> how they compare in accuracy. I was going to get another competitor
> called proxalrt into the ring as well, but the only place that carried
> it said they don't keep it in stock.
>
> We'll see.

[Thierry]

Darrel,
The Prox alert R5 new low price is 1045 USD. We sell direct.
The R5 outperforms everything available at similar price range.
It a real bargain.
Thanks,
Thierry

Darrel Toepfer > wrote in message >...
> Thierry wrote:
>
> > Hello,
> > Sorry to jump into your exchange ... You may consider trying a Prox
> > alert R5 which monitors up to three threats simultaneously.
> >
> > Don't ask me to elaborate online on other devices since i work for
> > Prox alert.
> >
> > As we are an honest company we have no problem to offer a 30 days
> > money back guarantee. www.proxalert.com (HQ in Phoenix AZ)
> >
> > We will be happy to answer your technical questions about affordable
> > collision avoidance devices.
>
> Thierry, I like the target squawk code readout as well, but it comes
> at more than double the price... Still alot cheaper than the $19k
> units that are out there too... <G>

[Loran]

If you read the aviation consumer they mention 2 other traffic
products that perfrom even better.


(Thierry) wrote in message >...
> Darrel,
> The Prox alert R5 new low price is 1045 USD. We sell direct.
> The R5 outperforms everything available at similar price range.
> It a real bargain.
> Thanks,
> Thierry
>
> Darrel Toepfer > wrote in message >...
> > Thierry wrote:
> >
> > > Hello,
> > > Sorry to jump into your exchange ... You may consider trying a Prox
> > > alert R5 which monitors up to three threats simultaneously.
> > >
> > > Don't ask me to elaborate online on other devices since i work for
> > > Prox alert.
> > >
> > > As we are an honest company we have no problem to offer a 30 days
> > > money back guarantee. www.proxalert.com (HQ in Phoenix AZ)
> > >
> > > We will be happy to answer your technical questions about affordable
> > > collision avoidance devices.
> >
> > Thierry, I like the target squawk code readout as well, but it comes
> > at more than double the price... Still alot cheaper than the $19k
> > units that are out there too... <G>

[Thierry]

Aviation consumer never tested the R5. They got one an will soon post a follow up.
Customers using the R5 said it's far better than the 2 other products.

(Loran) wrote in message >...
> If you read the aviation consumer they mention 2 other traffic
> products that perfrom even better.
>
>
> (Thierry) wrote in message >...
> > Darrel,
> > The Prox alert R5 new low price is 1045 USD. We sell direct.
> > The R5 outperforms everything available at similar price range.
> > It a real bargain.
> > Thanks,
> > Thierry
> >
> > Darrel Toepfer > wrote in message >...
> > > Thierry wrote:
> > >
> > > > Hello,
> > > > Sorry to jump into your exchange ... You may consider trying a Prox
> > > > alert R5 which monitors up to three threats simultaneously.
> > > >
> > > > Don't ask me to elaborate online on other devices since i work for
> > > > Prox alert.
> > > >
> > > > As we are an honest company we have no problem to offer a 30 days
> > > > money back guarantee. www.proxalert.com (HQ in Phoenix AZ)
> > > >
> > > > We will be happy to answer your technical questions about affordable
> > > > collision avoidance devices.
> > >
> > > Thierry, I like the target squawk code readout as well, but it comes
> > > at more than double the price... Still alot cheaper than the $19k
> > > units that are out there too... <G>