TPAS Airplane Detector-03 Nissan Altima

**thx1138** · 09-11-2010 12:18 AM

TPAS unit installed tonight. Provides distance readout and visual/audio warnings when you are in proximity of an aircraft.

Two modes: Enroute and TCA...roughly equivalent to Highway and city settings on a radar detector.

Thanks Switch626 for the idea.

**Google Adsense** · 09-11-2010 12:18 AM

**Akosikojak** · 09-11-2010 01:21 AM

How's the Aircraft Detector working out for ya so far? I know you just installed it but have you had any chance to test/use it?

**switch626** · 09-11-2010 01:25 AM

In a word, Awesome! I'm thrilled to see that you were able to acquire a TPAS. Now you will always know if there is a plane overhead when you see the white lines in the road.

Where did you mount your antenna? Did you patch the audio into your stereo?

**thx1138** · 09-11-2010 08:06 AM

Tests went well. It has correctly identified aircraft and alerted as they approached. I ran a BNC cable and placed the antenna behind my rear view mirror. Previously I had a external speaker mounted for my CB, but I connected the TPAS audio to that (My new Galaxy CB needs no external speaker)

With the antenna in it new location, it seems a bit sensitive. I may need to experiment with antenna mounting locations. Looking forward to a real encounter on the highway.

**OpenRoad** · 09-11-2010 12:54 PM

Sounds great, but isn't it called TCAS = Traffic Collision Avoidance System? (I'm a pilot, and never heard of TPAS)

http://adsb.tc.faa.gov/TCAS.htm

Ok, just zoomed in on photo - looks like TPAS is a brand name?

Edit - Ok, just found the manufacturer pdf - "TPAS" is a Trademark of SureCheck...
http://www.surecheck.net/library/TPAS_2-2_Full.pdf

From the TPAS manual - "Please note that TPAS is not designed to operate properly on the ground."

**OpenRoad** · 09-11-2010 01:14 PM

Just read the manual, looks interesting. I don't think many pilots use this, since regular TCAS offers more benefit (like direction and distance to other aircraft), but seems like something I should look into as well (for cars). Let us know how it works out for you. Great stuff.

Not sure how they are pulling this off. Aircraft transponders reply back to interrogation from ground based radar antennas. The returned signal time delay is converted to distance, but only from the fixed ground radar antenna. However, embedded in the signal is a timestamp, so maybe they are doing some tricky math to do this.. A transponder may reply to more than one ground based antenna, especially if you are in a metro area. The typical sweep time for a single interrogation is about 7 seconds.

Seems to me this setup should work. (Now, if the LEO turns off his transponder, you are out of luck - but likely he would get in trouble for doing so).

If you were located out west, I could help you test it by renting a plane and doing a few overflys in some out of the way rural area... Oh well....

Here is what looks like a better option. No external antenna, runs on batteries.
http://www.aviationpilotsupplies.com...fic-alert.html

**OpenRoad** · 09-11-2010 01:46 PM

Other thread about traffic patrol at 2200 feet above ground - too high for the TPAS which, according to the manual, only reaches up to 1,800 feet.
WA - Airborne trooper spots I-90 speeders

In hindsight, what would be much better is a police/aircraft scanner. The air-to-ground frequencies are easy to find online, or by doing a pre scan.
And a CB

**switch626** · 09-11-2010 01:48 PM

If I understand correctly, the transponder will respond to interrogation from the ground or also from other aircraft. The TPAS will tell you whether the plane in question is responding to interrogation from air or ground and whether you're in an area that has ground radar present. In your car, none of this means very much to you though. You only care about the proximity of an aircraft to you when you are about to cross VASCAR lines in the road.

The TPAS and similar systems judge distance by virtue of the signal strength of the airplane's transponder. It is also worth noting that this method is not extremely accurate, but is close enough for our purposes.

Thx and I did some testing on the viability of using a TPAS as a CM with good enough results that we now both have them installed in our cars. You can read more about that here Airborne Speed Trap Countermeasures - Revisited

I also had a real world encounter that sealed it for me. It was staged in the sense that I know the trap was there and active (Thanks to 'The Invisible Vervet', Trapster, and my CB). My experience in the live trap was that I would easily have had enough time to slow down and avoid a ticket if I were speeding as normal.

IMO, This method is tested and confirmed to be effective. In time, we will have unstaged real world encounters to talk about here as well.

Sorry if I'm writing too much here, I get very excited about this topic. This type of trap is a long standing problem for some folks, and we now have a practical solution.

**switch626** · 09-11-2010 01:52 PM

Originally Posted by OpenRoad

Other thread about traffic patrol at 2200 feet above ground - too high for the TPAS which, according to the manual, only reaches up to 1,800 feet.
WA - Airborne trooper spots I-90 speeders

In hindsight, what would be much better is a police/aircraft scanner. The air-to-ground frequencies are easy to find online, or by doing a pre scan.

We tested at 2500' and I had no problem detecting the aircraft. The newer PCAS and similar systems are altitude aware (which presents a problem as far as audible alerts). Still they do track the plaanes. The PCAS's older cousin, the TPAS, is not smart enough to know about altitude, making it perfect for this application.

The problem is that Surecheck has not made TPAS for quote some time. The only way to get one is to buy it on Ebay when you get the opportunity.

**OpenRoad** · 09-11-2010 01:56 PM

Originally Posted by switch626

Originally Posted by OpenRoad

Other thread about traffic patrol at 2200 feet above ground - too high for the TPAS which, according to the manual, only reaches up to 1,800 feet.
WA - Airborne trooper spots I-90 speeders

In hindsight, what would be much better is a police/aircraft scanner. The air-to-ground frequencies are easy to find online, or by doing a pre scan.

We tested at 2500' and I had no problem detecting the aircraft. The newer PCAS and similar systems are altitude aware (which presents a problem as far as audible alerts). Still they do track the plaanes. The PCAS's older cousin, the TPAS, is not smart enough to know about altitude, making it perfect for this application.

The problem is that Surecheck has not made TPAS for quote some time. The only way to get one is to buy it on Ebay when you get the opportunity.

Looks like our posts passed each other.... I found a newer model for $299 - not sure what you paid. No external antenna, runs on batteries.

http://www.aviationpilotsupplies.com...fic-alert.html