Help us with this petition for security on anti-collision systems

On Thursday, May 28, 2015 at 5:22:47 AM UTC-7, pcool wrote:

Who is incompatible with who? You have the freedom to choose a device
manufacturer.

Well, there is one device that is installed in 25,000 gliders worldwide and one that is installed in...how many? 500? People can decide which is the tail and which is the dog when it comes to wagging. I think if I showed up in most European countries with an electrical device requiring 110 volts I would not get agreement that the entire continent is incompatible and needs to change to 110 volts.

The TAdvisor, and probably the OGN devices soon, are not worst than flarm to do this job.

That isn't even how they talk about themselves.

Here is what T-Advisor says about the themselves: "The functioning idea of the T-Advisor is not the one of an Anticollision or Collision Avoidance System, rather the one of the Traffic Advisor, an Early Warning System."

OGN's main purpose is tracking, not collision detection. Here is what they say about themselves: "The objective of the Open Glider Network is to create and maintain a unified tracking platform for gliders and other GA aircraft. Currently OGN focuses on tracking aircraft equipped with FLARM, FLARM-compatible devices or OGN tracker."

Hair-splitting and straw-manning are not a productive ways to advance the conversation.

9B

At 12:47 28 May 2015, Martin Gregorie wrote:
On Thu, 28 May 2015 14:22:41 +0200, pcool wrote:

I fully agree with Bob, it is pointless to ask Flarm to open the
protocol. What we need is several other manufacturers selling their own
devices, based on the OGN open software for example. I have not signed
the petition for this reason.

IIRC the reason that FLARM encrypted the protocol was that the OGN crew
were refusing to honour the 'do not track' bit thus exposing the
whereabouts of people who didn't want to be tracked.

In view of that record, why should we trust OGN to do the right thing?

Firstly, the Easter Egg was built into the previous version of FLARM
firmware long before OGN can into being. OGN was not the cause. As I
understand it the Easter Egg was to ensure that users were on reasonably
up-to-date Firmware.

Secondly, any transmissions received by an OGN Receiver that have the
Do-Not-Track bit set are discarded at the receiver. There are never sent to
the Server.

I won't sign the petition either. If DSX want to sell anti-collision kit,

let them drop their NIH attitude and join LX etc in using the de-facto
standard protocol. As long as FLARM sell licences to allow third parties
to use it they are no better or worse than, e.g. Oracle with their
proprietary attitude to Java or the companies who hold patents that
widely used wireless comms standards depend on: think WiFi.

BTW, has the DSX protocol been published? On a Creative Commons or GPL
license?

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.

There is a bit of benefit in having a consistent algorithm - for instance, in a head-to-head scenario having both systems determine that the traffic is slightly to the right wouldn't be all that great. Glider flying is dynamic and consistent dynamic behavior with humans in the control loop is important. There are other more subtle issues with respect to Stealth mode that also require a single system. Interoperability is generally better if you have a single system design rather than having to rely on adherence to standards.

9B

On Thursday, May 28, 2015 at 7:04:44 AM UTC-7, Andy Blackburn wrote:

There is a bit of benefit in having a consistent algorithm - for instance, in a head-to-head scenario having both systems determine that the traffic is slightly to the right wouldn't be all that great.

[[[[ Sorry, meant to say one says to the left and one says to the right. Dyslexia ]]]]]]

- 9B

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

On Thursday, May 28, 2015 at 7:23:16 AM UTC-7, Tango Eight wrote:

....also less processor demand (processing two dozen other gliders in a thermal might be a little intensive!).

Good add - everyone responsible for their own prediction - do it only once and consistently for everyone in range. Otherwise everyone in a thermal gets a slightly different track prediction based on what data they receive - or algorithm they use. Imagine the dynamic effects as pilots react differentially based on slightly different predictions and create new tracks and predictions, all based on slightly different interpretations of where others are headed. Emergent behavior, possibly not stable, probably unpredictable to a greater extent than normal thermal flying.

9B

Interesting podcast on FLARM.

"In this episode we talk with Gerhard Wesp, Development Manager Avionics at Flarm Technology GmbH about FLARM, a collision avoidance system for gliders and general aviation. We talk about the history of the FLARM system as well as about newer developments such as the PowerFlarm. Mostly, however, we talk about how FLARM works and how PowerFlarm integrates with Transponders and ADS-B systems."

Omegatau - omega tau covers a mix if topics from engineering and science; the selection of topics is guided by our own interest (as well as listener suggestions). Since we have German and English language episodes, the tag cloud is a mix of German and English words. Click on a tag to get to the respective episodes.


http://omegataupodcast.net/2014/03/1...ce-with-flarm/

A look from the engineering point of view.

Dan

I will not be signing the petition.
FLARM is a private enterprise and deserves to reap the rewards of its work.
FLARM is a optional instrument for pilots, not a mandated piece of equipment. The issue with contest pilots being required to use FLARM is an SSA matter.
I would hope that glider pilots choose to install a transponder BEFORE they add a FLARM to their aircraft.

On Thursday, May 28, 2015 at 4:26:08 PM UTC+1, wrote:
I will not be signing the petition.
FLARM is a private enterprise and deserves to reap the rewards of its work.
FLARM is a optional instrument for pilots, not a mandated piece of equipment. The issue with contest pilots being required to use FLARM is an SSA matter.
I would hope that glider pilots choose to install a transponder BEFORE they add a FLARM to their aircraft.

Out of ignorance and curiosity, what are the relative proportions of glider collisions in the US between gliders versus between gliders and CA/GA aircraft?

John Galloway

On Thursday, May 28, 2015 at 9:06:14 AM UTC-7, wrote:
On Thursday, May 28, 2015 at 4:26:08 PM UTC+1, wrote:
I will not be signing the petition.
FLARM is a private enterprise and deserves to reap the rewards of its work.
FLARM is a optional instrument for pilots, not a mandated piece of equipment. The issue with contest pilots being required to use FLARM is an SSA matter.
I would hope that glider pilots choose to install a transponder BEFORE they add a FLARM to their aircraft.

Out of ignorance and curiosity, what are the relative proportions of glider collisions in the US between gliders versus between gliders and CA/GA aircraft?

John Galloway

From 1994 through 2013 there were 20 reported midairs involving gliders un the US - 12 were glider-glider, 3 were glider-towplane, 4 were glider-GA and one was towplane-GA (the glider was on tow). There were 16 total fatalities as a result.

These were only the ones that were serious enough to be reported to the authorities and recorded in the official record. There were probably others with minor or no damage that were not reported.

Based on the statistics FLARM is a more important investment than a transponder, though obviously that consideration includes the fact that the statistics reflect whatever deployment of transponders existed prior to introduction of Flarm and may have reduced collisions with other aircraft types over the period.

Andy
9B