"Do It Yourself" airborne proximity warning device

Linar,

Thanks for the interesting github pointer.

I'm not quite up to date on the state of Flarm reverse engineering and interoperability. For example, does the SoftRf understand the Flarm Frequency hopping?

The whole Flarm proprietary thing seems wrong, but on the other hand it funds a somewhat working Flarm system. Given that it exists, the most likely path to an open system seems like ADSB and/or an open software load for the existing Flarm boxes.

I wonder if ADSB is a viable path for gliders. Has anybody looked at if the broadcast ADSB state vectors are suitable for feeding a collision detection algorithm like the one in Flarm?

-Stu

Stu,

Â*For example, does the SoftRf understand the Flarm Frequency hopping?

At first, channel hopping (CH) is more "radio signal obstruction clearance" rather than "security" feature.
Second: CH is not a factor for major FLARM's EU market ( only 2 channels are in use ), but "is"
for North (65 channels) and South America / Australia (24 channels).

"FLARM-alike" OGN CH was implemented in March'17 by Pawel Jalocha - leading developer
of OGN tracker. According to this source ( http://wiki.glidernet.org/history ), he had
relations with Flarm Technology GmbH in past.
SoftRF had adopted OGN CH algorithm.

Is OGN CH equal to FLARM CH in North America?
There were no neither positive nor negative reports from NA's SoftRF
builders till today.
So you have a chance to be the first one who will answer this question.

Regards,
Linar.

Folks, what we need is a system that warns of ANY aircraft that is about to come too close. The major flaw of most approaches is requiring that the other guy be properly equipped. It is not human nature for people to agree so there will always be many avoiders, contrarians, competitors, and folks too poor to comply even if they want to. Mutually inncompatible systems will proliferate and no single collaborative system will make more than a dent in the collision threat.

We as PICs should take upon ourselves the responsibility of not flying into someone and being aware of impending traffic - I mean beyond 'See and Avoid'.
A simple device that warns of impending collision would focus our attention to taking evasive action. It would not need to be very sophisticated, but some simple indication of direction would make it more effective.

Radar may be the most practical way. Detection at short distances does not require much power, nor equipment sophistication.

Some observations -

Flarm appears to be the best thought out existing system. PowerFlarm should be called Low-power Flarm because it operates as an unlicensed low power ISM band gadget. Range and reliability are limited due to lack of signal strength. IMHO, the FCC denied licensing of Flarm and refused to allocate spectrum to protect the inferior ADS-B already chosen for Nexgen.

PowerFlarm is priced out of reach for most glider operators. Clubs usually don't have it in their ships.

I live near a Class C airport. Only about 1/4 of the traffic I detect in the area is currently squittering ADS-B. Devices like Stratux don't yet show the majority of existing traffic.

IMHO, aircraft traveling too fast to see and be seen (maybe 175 Kn) should have active radar, to avoid anything from drones on up.

The brave new world of Software Defined Radio/Cognitive Radio is a godsend for quickly developing new technology, including radar. The open source community has embraced the technology!!!

Of my many close calls, only one was a glider, half were military, and about 3/4 came from behind me. I sure hate hearing engines from within a glider!

On Saturday, January 6, 2018 at 12:04:29 PM UTC-8, Wit Wisniewski wrote:

Radar may be the most practical way. Detection at short distances does not require much power, nor equipment sophistication.


Can I have some of whatever you are smoking?

Radar, as in what? Actual primary radar for collision avoidance? Please describe how this would not require much equipment sophistication. You planning on mounting phased array antennas where on the glider? Transmitting on what frequencies? Do you have a estimate on the development and FCC approval costs?

On Saturday, January 6, 2018 at 2:04:29 PM UTC-6, Wit Wisniewski wrote:
Folks, what we need is a system that warns of ANY aircraft that is about to come too close. The major flaw of most approaches is requiring that the other guy be properly equipped. It is not human nature for people to agree so there will always be many avoiders, contrarians, competitors, and folks too poor to comply even if they want to. Mutually inncompatible systems will proliferate and no single collaborative system will make more than a dent in the collision threat.

We as PICs should take upon ourselves the responsibility of not flying into someone and being aware of impending traffic - I mean beyond 'See and Avoid'.
A simple device that warns of impending collision would focus our attention to taking evasive action. It would not need to be very sophisticated, but some simple indication of direction would make it more effective.

Radar may be the most practical way. Detection at short distances does not require much power, nor equipment sophistication.

Some observations -

Flarm appears to be the best thought out existing system. PowerFlarm should be called Low-power Flarm because it operates as an unlicensed low power ISM band gadget. Range and reliability are limited due to lack of signal strength. IMHO, the FCC denied licensing of Flarm and refused to allocate spectrum to protect the inferior ADS-B already chosen for Nexgen.

PowerFlarm is priced out of reach for most glider operators. Clubs usually don't have it in their ships.

I live near a Class C airport. Only about 1/4 of the traffic I detect in the area is currently squittering ADS-B. Devices like Stratux don't yet show the majority of existing traffic.

IMHO, aircraft traveling too fast to see and be seen (maybe 175 Kn) should have active radar, to avoid anything from drones on up.

The brave new world of Software Defined Radio/Cognitive Radio is a godsend for quickly developing new technology, including radar. The open source community has embraced the technology!!!

Of my many close calls, only one was a glider, half were military, and about 3/4 came from behind me. I sure hate hearing engines from within a glider!

In the US, the system you are looking for is ADS-B. Systems like Stratux show all existing ADS-B AND transponder equipped aircraft if you are within range of an ADS-B ground station and you are ADS-B OUT equipped. If you are flying within the vicinity of Class C airspace and you are not seeing the vast majority of GA traffic on your Stratux ADS-B receiver (except for gliders who are are not transponder equipped), you are either not ADS-B OUT equipped, or your system is not configured properly for the ground station TIS-B to work properly with your ADS-B IN equipment.

On Tuesday, December 10, 2013 at 1:22:31 AM UTC+11, Linar Yusupov wrote:
Dear rec.aviation.soaring subscribers!

I would like to present you PDF slides of one DIY R&D project.
The slides are about open platform airborne proximity warning device.
It operates at ISM band radio but also capable to receive ADS-B reports at aviation frequency.
It is mainly targeted for our local soaring club use but can also attract pilots worldwide.

The presentation is downloadable at: https://github.com/lyusupov/Argus/ra...g_Dev ice.pdf

If upon reading you'll find it worthwhile, feel yourself free to share this news with someone
upon your discretion.

Don't hesitate to ask any questions here. FAQ document is yet to be created.

Best regards!
Linar Yusupov.

Hi Linar -- can the "TTGO T-Beam" board be used as a ground-based OGN receiver?

Thanks, John

You can download the FCC and IC testing report for the PowerFLARM CORE/Brick, pictures, etc. at https://apps.fcc.gov/oetcf/eas/repor...id=ZKUGC625162

They are thorough.

On Tuesday, August 27, 2019 at 5:43:55 PM UTC-5, Dan Daly wrote:
You can download the FCC and IC testing report for the PowerFLARM CORE/Brick, pictures, etc. at https://apps.fcc.gov/oetcf/eas/repor...id=ZKUGC625162

They are thorough.

Thanks for the link. Now I know what the inside of a Flarm looks like.

I wonder why they didn't test with both antennas active. If I read the test report correctly, their radiated power (33mW) is way lower than the inteference limit (1W), so it seems like it would have passed easily.

There was another limit around 60mW for something?

On Wednesday, August 28, 2019 at 8:59:02 AM UTC-4, wrote:
On Tuesday, August 27, 2019 at 5:43:55 PM UTC-5, Dan Daly wrote:
You can download the FCC and IC testing report for the PowerFLARM CORE/Brick, pictures, etc. at https://apps.fcc.gov/oetcf/eas/repor...id=ZKUGC625162

They are thorough.

Thanks for the link. Now I know what the inside of a Flarm looks like.

I wonder why they didn't test with both antennas active. If I read the test report correctly, their radiated power (33mW) is way lower than the inteference limit (1W), so it seems like it would have passed easily.

There was another limit around 60mW for something?

The 1W limit is designed for devices on the ground. Since your large Line of Sight range at altitude makes it much more likely that you will interfere with someone else - so they reduce the power - your reach is much greater.. We 'see' PowerFLARM CORE/Bricks at about 120 km with radiated power of 0..018W on our OGN system. If you boost the power, and there are a lot of gliders/towplanes fitted (we have around 40 in my area, increasing by the day), the chances of mutual interference increases. And, the Industrial, Scientific, and Medical (ISM) 902-928 MHz band is pretty busy.

Here's the LXNAV report link https://apps.fcc.gov/oetcf/eas/repor...d=2ASPHLXNAVAM
Looks like it radiates 0.07W...