PowerFlarm does Flarm (obviously) and mode S with direction and range
How does it do direction on Mode S?
Elementary Mode S doesn't radiate anything useful for that.
Enhanced Mode S (found on say TBMs and up) usually radiates lat/long so one could work it out from that, same as FLARM does.
Also, AFAIK, all Mode S boxes do Mode C. I think there is a way to disable Mode C on say a GTX330 and run it as a Mode A + S box, but why would one?
PowerFlarm does Flarm (obviously) and mode S with direction and range
How does it do direction on Mode S?
It doesn't. Only when there is an ADS-B signal (GPS lat/long).
I think PowerFLARM delivers a lot of value for the money. Obviously a TAS system is better but I consider to be too expensive. Usually I get traffic information from FIS/ATC but PowerFLARM is very useful to tell me about other traffic in terminal areas. I actually do find most targets it shows and only very rarely I spot a target that PowerFLARM doesn't display. Unfortunately I can't tell whether it's because the target does not have a transponder active or PowerFLARM doesn't receive the signal.
The UK might be the worst case for unknown traffic. IFR in airspace G without flight plan, restricted service level from FIS, frequent weather situations with low visibility and cloud base, a lot of traffic without transponders. If I did a lot of flying in the UK, I might invest in TAS.
A year or two ago a colleague (who is very much involved in the gliding scene) very kindly lent me his FLARM box.
I did a few flights with it, all within the UK.
I didn't intentionally fly near known gliding sites, although there is plenty of gliding in the UK.
But I never once picked up anything. Not a single return.
What does this mean?
I would never claim that the £12k spent on the full TCAS is good value (it's totally a matter of opinion whether the ~ 2 mid-airs a year the UK has justifies this, especially given the amount of disruption to the aircraft and the potential for bodges which will come to light years later) but if you go for a flight anywhere, you pick up loads of targets, and many potentially conflicting, and this is continuous.
So, on this admittedly rather useless data, the ModeC v. FLARM adoption rates differ by a good number of orders of magnitude.
I've said to PowerFLARM that if they can do Mode C azimuth, they will have a winner which "everybody" is waiting for. But they didn't seem interested.
The website says:
ARINC 429 for panelmount GPS like GARMIN® GNS/GTN/G1000 (TRX-1500A only)
Now that will require an STC…
OK, but my Q was: will it feed data to a GTN750?
That’s what I just quoted, isn’t it?
Zaon’s box does Mode A & C with direction and range (and I think mode S) but not FLARM.
Correct, it does detect “mode S transponders” based on that they are downwards compatible. They receive the squawk code, this mode A, and receives the altitude, this is mode C. Mode S (standard does 24 bit ICAO adress, airspeed range, aircraft type), enhanced mode S and ADS-B can provide even more information.
So an old mode C transponder does actually do mode A + C (squawk and altitude)
A mode S transponder will do mode A + C + S when used normally.
Also, AFAIK, all Mode S boxes do Mode C. I think there is a way to disable Mode C on say a GTX330 and run it as a Mode A + S box, but why would one?
In ON mode a mode S will transponder mode A and mode S (no altitude). An older mode C transponder in ON would only do only mode A, (no altitude)
In ALT mode a mode S transponder will do A+C+S, and an older mode C transponder would do mode A+C.
In GND mode a mode S transponder will do mode S only (only replies to selective calling, to prevent exessive data.
In Standby mode a transponder should not transmist (some do anyway)
How does it do direction on Mode S?
Direction finding methodes can be used. Most advanced low cost sytems use this doppler effect to get a sense of direction (accurate withing about 60 degrees). This is not very accurate. I don’t like that they can plot aircraft on a map, based on these technoligy. All these low cust units use signal strength as indication of distance. As such an airliner with a more powerfull transponder will always look closer than a VLA with a minimum power transponder.
More advanced low cost units use the ADS-B principle, which will be the way for the future or a combination of all these techniques. These systems give the highest possible accuracy.
More expensive units are active units, suchs as does from Garmin and Avidyne. They interrogate themselfs, and see replies from other aircraft. Based on timing, their distance indication is much better than those systems that use signal strength. To give a sense of direction they use multiple antenna’s and doppler technique. Using more antenna’s their sense of direction is better than that of low cost systems. Both distance and direction will be less accurate than using ADS-B.
But I never once picked up anything. Not a single return. What does this mean?
Flarm uses standard ISM frequency and low power to be able to use these transmitters unlicensed. The range of Flarm is far less than that of any other traffic avoidance system. Accuracy is just like ADS-B very good.
I would never claim that the £12k spent on the full TCAS is good value
You are likely operating TAS instead of TCAS. TAS gives only traffic information, while TCAS will communicate with other TCAS system, and have one aircraft climb and the other decend. TAS and TCAS or NOT the same, and generally TCAS is only used on large aircraft (mandatory).
I’ve said to PowerFLARM that if they can do Mode C azimuth,
With the rising of ADS-B this wouldn’t be very interesting. The doppler technique will always lack accuracy, while they don’t have this disadvantage with ADS-B. Flarm and ADS-B is very similair. The range of ADS-B is much bigger because it uses a certified aviation transmitter with 75 – 250 Watt power, instead of ISM with something like 100 mW.
Now that will require an STC…
I wouldn’t see why it should be done with an expensive STC for most applications. A minor change would be sufficient for most applications
the Zaon box is useless as the manufacturer is gone bust.
The 1500a can technically connected to a Garmin GNS or GTN, the powerflarm cannot.
I wonder, can the 1500a be connected to an Aspen with the hazard awareness software unlock?
