ADS-B - what practical relevance in Europe?

Peter wrote:

The need for a W GPS is bogus; you get more integrity but no more accuracy.

My takeaway from that thread is that SBAS gives you 2-3 times the accuracy but that basic GPS accuracy is (in most cases) sufficient.

Peter wrote:

I wonder what would happen if somebody did a firmware mod which outputs SIL=3

No need for a firmware mod. One of the configuration items in TT21 is the certification level of the GPS source.

greg_mp wrote:

Is there a real TCAS option for our small plane? I mean a device that can spot a C mode?

Clearly yes. I use Powerflarm and it does exactly that: It shows:

- ADS-B targets with direction and altitude difference
- FLARM targets (Gliders, Helicopters) with direction and altitude difference
- Mode C Targets with altitude difference and a range ring.

There are several versions which can be built in and linked to different EFIS, my own is a formerly portable one which sits on a tray with 2 outside antennas. I am very happy with it.

What I like is that it shows ALL kinds of traffic which are of concern to you: Gliders via Flarm, Mode C targets and those with ADS-B. As Gliders are a massive problem in many places, the capability of showing FLARM makes this superior even to the professional TCAS.

In general, “professional” TCAS always works with vertical separation, not horizontal. That is why I think that PF or similar devices do the job nice enough, even without calling out in which direction to divert. If you can keep the Delta of the Altitude constant, you will avoid the other traffic in any case as you are at a different altitude.

Peter wrote:

However, the current mad UK CAA bust-them-all policy ensures that around 50% fly with their TXPs turned off…

This is a pretty unique situation in the UK however and looking at FR there is still a lot of traffic displayed which would show on PowerFlarm or similar. And it is a totally unacceptable situation too, as flying with the transponder off is illegal. It would be a safety case for ICAO if the CAA won’t do anything about it or are causally involved.

Is there a real TCAS option for our small plane? I mean a device that can spot a C mode?

Clearly yes. I use Powerflarm and it does exactly that: It shows:

Powerflarm and similar devices can be of great use but it is important to understand it is not an active TCAS / TCAD. It will not detect the exact range and bearing to the target. Also it will not work in mountain valleys or other areas without secondary ATC radar coverage.

I even talked to a maintenace shop a while ago and before installing any of those system they did move to having the customers sign a waiver they did understand all of this as there was so much confusion and complaints.

The cheapest real active system out there is probably the LYNX NGT-9000 with active traffic option.

I did type many of those things so often by email and in forums that I did actually compile a summary so I do not have to do so much typing:
https://golze.tech/articles_european_traffic_detection.jsp

Mooney_Driver wrote:

That is why I think that PF or similar devices do the job nice enough, even without calling out in which direction to divert. If you can keep the Delta of the Altitude constant, you will avoid the other traffic in any case as you are at a different altitude.

I also think this is a very important approach. Most try to see the target in such situations which is nearly impossible. Simply changing the altitude works much better. BUT make sure your system uses the proper altitude reference. Too many systems compare baro with GPS altitude and then your 300-500ft altitude buffer can be gone. I have seen even up to 1000ft error due to this at altitude.

The real solution is a SMOP: https://www.mdpi.com/1424-8220/23/14/6297

Abstract: The development of high-performance, low-cost unmanned aerial vehicles paired with rapid progress in vision-based perception systems herald a new era of autonomous flight systems with mission-ready capabilities. One of the key features of an autonomous UAV is a robust midair collision avoidance strategy. This paper proposes a vision-based in-flight collision avoidance system based on background subtraction using an embedded computing system for unmanned aerial vehicles (UAVs). The pipeline of proposed in-flight collision avoidance system is as follows: (i) subtract dynamic background subtraction to remove it and to detect moving objects, (ii) denoise using morphology and binarization methods, (iii) cluster the moving objects and remove noise blobs, using Euclidean clustering, (iv) distinguish independent objects and track the movement using the Kalman filter, and (v) avoid collision, using the proposed decision-making techniques. This work focuses on the design and the demonstration of a vision-based fast-moving object detection and tracking system with decision-making capabilities to perform evasive maneuvers to replace a high-vision system such as event camera. The novelty of our method lies in the motion-compensating moving object detection framework, which accomplishes the task with background subtraction via a two-dimensional transformation approximation. Clustering and tracking algorithms process detection data to track independent objects, and stereo-camera-based distance estimation is conducted to estimate the three-dimensional trajectory, which is then used during decision-making procedures. The examination of the system is conducted with a test quadrotor UAV, and appropriate algorithm parameters for various requirements are deduced.

eurogaguest1980 wrote:

The real solution is a SMOP: https://www.mdpi.com/1424-8220/23/14/6297

UAV uses camera for obstacle avoidance, it can be used, but the speed and range are very far from th eone used in GA. but I think with some good cameras (2 at least) and nice algos, it can work.

Is this the same vision system as used on Tesla driverless cars? I’m not sure they have proven themselves infallible yet and that’s at slower speeds and closer obstacles.

I have no idea of specific of the various brands, but it’s all based on forms recognition, very probably by IC tightly coupled with camera, but it!s more and more convincing. Have a look at this one, at 10’
https://youtu.be/bNvwoPv2jvg?feature=shared