Lee. Thanks for quick response.
For Mode-S, all you have is relative altitude, but no distance, therefore it is impossible to calculate the angle to the horizon, consider the angle to the horizon of +500ft at a distance of 100m and 1000m - completely different.
The altitude difference could be added for Mode-S altitude if it is valuable, but this would be of the form
"Notice, traffic, 500ft above", thus not indicating elevation to the horizon
I think this is a great idea. Giving height adds a huge amount to the message. Roughly where to look vertically but more importantly with the decision whether to climb or descend.
Thinking about ADS-B/P3I alerts the perfect solution would be to announce relative height if "level" and within short range ie in danger of collision - then even if not visual one can decide whether to climb or descend. Maybe getting too complex but think it would be very useful safety aid.
1. A manual mute: I like this idea with a configurable timeout, in other words mute for X minutes, then automatically re-enable, or mute permanently (or pull out the plug!) This could solve the issue of Taxi, Take off & Landing
My only comment is if a software mute how this would be accessed? Going into the configuration of the PAW in-flight is tricky. I feel a hardware mute is best, but implementing a time out would be difficult! Maybe just pulling the plug is simplest/best solution here! ;-)
2. Ground speed filter: if my speed is less than X Kns, then mute the audio.
Personally I
really like this idea and I think this should
also apply to P3I transmissions (both optionally from config).
Interestingly (as I am sure you know) the procedure for Mode S transponders is to leave on standby mode until entering the runway threshold or in the case of aircraft that have a sensor on the undercarriage until after take-off and similarly on landing to switch back to standby after vacating the runway or having touched down. It seems to me that this procedure is equally relevant to PAW but due to the lack of easily accessible controls on the PAW device that a more intelligent process is needed ie the speed filter.
These could both be config options, and in the case of Helicoptor, Paraglider, Hanglider, the speed option may not be a good choice.
Absolutely
Giles