On Thursday, May 28, 2015 at 10:04:44 AM UTC-4, Andy Blackburn wrote:
On Thursday, May 28, 2015 at 6:29:35 AM UTC-7, Tango Eight wrote:
On Thursday, May 28, 2015 at 9:00:06 AM UTC-4, Tim Newport-Peace wrote:


Even if Flarm did open their encoding, DSX is still not Flarm-compatible.
The do not have the predictive algorithm that Flarm does.


That's not true (logically). One need only have open transmission of 3D location, velocity, turn rate. The predictive element of things is done on the receiving end and need not be symmetric. Better predictive capability yields fewer nuisance alarms.

Most US guys, I think, never heard of DSX until this thread. Did DSX and Flarm have an agreement or did they just hack the protocol?


regards,
Evan Ludeman / T8

Actually, the Flarm engineers told me that the prediction is done on the transmit side for Flarm. I'm told this is helpful because it is more accurate in the event of dropped packets, which can happen for a variety of reasons. Obviously it doesn't work this way for ADS-B traffic. Collision detection and warning is done on the receive side.

Ah, I made an inference I should not have based on some other conversation. Yes of course: you need data over time to establish trends and projections. And so it absolutely has to be done on the transmission side. Limited range, spotty reception, also less processor demand (processing two dozen other gliders in a thermal might be a little intensive!). Thanks.

-Evan