Skyecho

[RFguy]

Downunder, you are wrong.

The SkyEcho is an approved device

 

You apply for the 6 digit hex code for your SKyEcho and they give you one, in about 1 hour.

In the database, you are no different to a Mode S transponder

 

The SkyEcho is not some random device, you apply for your number just like a Mode S transponder.

 

I am really a bit dissapointed at you Downunder for not getting your facts straight before speaking like the gospel on this forum

 

 

 

 

Edited December 10, 2020 by RFguy

[Garfly]

 

Mark, 

 

regarding whether the SkyEcho can be seen on TCAS I posted this on the thread you started last July. 

Have you heard otherwise more recently?

 

"I've read that the SE2 will be seen by all newer TCAS displays (albeit without triggering Resolution Advisories). And there are various other cockpit displays that will display ADSB (SIL=1 or above) traffic. But what I'm still interested to know is just how many of the commercial aircraft that we're likely to share airspace with actually are so equipped. In any case, with a SE2 we should be able to see them and ATC might be in a position to spot impending conflicts."

[Kyle Communications]

Hi Gary

 

No I havent heard anything further. i read a bit more about it though and there is a small difference in why it cant been seen but not sure if it is true or not. 

 

On another note I have my V16 running here and it seems to be pretty good so far. It does require some adjustment of levels as it is quite configurable. Rainer has a setup on the MGL forum..the new forum the old one has been shut down

 

[graham brown]

ATC can see your skyecho. I have asked them and they can. I have also had 2 IFR flights advised of VFR traffic which was my sky echo. TCAS is another matter as they are designed to interact with transponders. ADSB IN is needed to see ADSB out. If the TCAS has ADSB IN capability they will see you.

[RFguy]

Good stuff Graham

Yes , Graham is right about TCAS interaction. Legacy TCAS works like a conventional ground based SSR  - position determined by time delay, altitude report and direction. Newer TCAS adds information gathered by ADSB broadcasts which have position additionally known by GPS ..

 

The primary radars that work by direct radio reflections are being decommissioned with the uptake of Mode S .. Mode S provides solutions to congested 1090 MHz airspace since it can mute an individual transponder (1090S) and transmit high reliability position fixes (1090ES)

 

A high  use of broadcast only ADSB (DF18 format)  like Skyecho (EC systems)  in CTA/CTZ will generate more 1090 MHz radio traffic., so interrogated Mode S systems in CTA/CTZ are preferred by the ATC operators.  The limited range of these EC devices would reduce the potential for radio congestion of 1090 MHz.

 

I will make some enquiries at ASA through my contact on what the ATC person sees.

 

As you can see, I'd done a fair bit of reading since I asked a question about this some months ago, and have written a signal processing script from scratch  to test transponders on my bench.
I will put my SkyEcho on my bench in a TEM cell and shielded box and see exactly what it is transmitting. The Majura SSR is only about 2km away.... so I set the transponders to 2100 and use the FAA test regime.

 

 

 

Edited December 10, 2020 by RFguy

[Gaznav]

Hi, I’m a Pom that has been using SkyEcho in the UK for the past 3 years. Firstly with SkyEcho1 and then with SkyEcho2 later on. In the UK our plan is to use it mainly for Air-to-Air, whereas in Oz I believe the grand plan is to use it for Air-to-Air and Air-to-Ground using Airservices Australia’s WAM and ADS-B set ups. What sort of ranges are you getting picked up at with Airservices Australia?

 

If you have any questions on my experience with SkyEcho, the UK UAT trial and FLARM reception then fire away.

 

Best, Gaz

[graham brown]

Air to air the range is very good. 50 miles at least. Flight radar 24 it’s not very good, about 20 miles from towns with receivers. Not sure what Airservices range is but they saw me over the Barrington ranges which is remote. 

 

[Gaznav]

 

Thanks Graham. I’ll show you a few Air-to-Air examples in a moment. But we have a network of amateur built and maintained ADS-B receivers in the UK (some are for UK system called Pilot Aware and some for things like Flight Radar 24). The Pilot Aware system has just launched a range analysis tool that shows what range and azimuth from your aircraft that your CAP1391 device (read SkyEcho) was received at (it is important to note that this shows the “up to the maximum range” that you flew from the ground station - so if the receiver is at your airfield and you stay in the circuit, then you may only see 2nm). The period of data can be set, so this is the 30 day data for a SkyEcho in an all-metal PA28 at a relatively busy flying school - sorry the data is in km.

 

 

So, as these are amateur ground stations using say 7dB antennae, are the Airservices Australia ADS-B and WAM receivers giving you any better than say 20-25km for reliable tracking as shown here? If anyone has a screen shot of the performance of Airservices Australia’s reception range, then I’d be really grateful if they could share it.

 

Moving onto SkyEcho’s receiver performance Air-to-Air, then for a reliable detection and track, I tend to get up to 5nm for PowerFLARM, 20-25nm for a Class 2 Mode S ES transponder in a light aircraft (emitting between 70W to 170W) and up to 120nm for a Class 1 Mode S ES transponder in an airliner (emitting between 250W to 500W).

 

In the above image you can see my aircraft detecting a PowerFLARM (4067E9) at around 5nm and a Vans RV8 (G-RVFT) at around 20nm.

 

This image is the SkyEcho picking up 500W airliners whilst in flight. As you can see, there are some that are 110nm away to the North.

 

I hope that helps with the debate that you have been having on this forum. I would be grateful for your experiences with certified ADS-B systems. We don’t have SDA=1 in our SkyEchos (yet), so knowing what range you are detected by the certified systems of Airservices Australia would be really useful. Further, whilst you won’t generate a TCAS/ACAS RA, you will show up on Boeing and Airbus CDTI (Cockpit Display of Traffic Information) and ATSAW (Air Traffic Situational Awareness) displays. So if any of you have data on the detection of SkyEcho by airliners using CDTI and ATSAW then that would also be great. As I say, we don’t have SDA=1 in the UK yet, so certified ADS-B In doesn’t display us at present (we’re hoping that will change in the New Year).

 

Best, Gaz

 

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[Gaznav]

PS. I should add that I don’t work for uAvionix. I am a WG CDR Fast Jet Weapon Systems Officer (was Navigator) in the RAF with a really keen interest in the use of ADS-B in General Aviation. 👍

[Kyle Communications]

The Pilot Aware system must have a series of antennas round style head on a cardinal arrangement to get those tracks...Do you know if it is a rotating switched arrangement ? or just a dopler arrangement for RSSI for the reciever?

 

[Gaznav]

53 minutes ago, Kyle Communications said:

The Pilot Aware system must have a series of antennas round style head on a cardinal arrangement to get those tracks...Do you know if it is a rotating switched arrangement ? or just a dopler arrangement for RSSI for the reciever?

 

Hi Kyle, no they receive the ADS-B tracks (with their GPS) positions, and with the ground station position, they crunch the numbers of range and angle. It’s known as Pilot Aware VECTOR and it’s a free system they are offering people in the UK to check the ranges of their ADS-B, FLARM or P3i (which is a proprietary signal from Pilot Aware devices) installations. It’s a pretty neat system, but it does have a draw back - in that the ground station receivers aren’t a set standard (so they could have 3dB, 5dB, 7dB or even high end 9dB antennae) and it will only report the ranges that you fly from those receivers (so if you only fly 10 miles from a ground station, it will only report 10 miles). So the polar diagram can be very deceptive as it is not showing received strength like a normal diagram, but only the data that has been received - it’s good for the ‘knowns’, but not so good for the ‘unknowns’, if you get what I mean?

 

Here is a link to their ATOM station - as you can see it is basic Raspberry Pi, SDR and an 1090 MHz antenna: https://global-uploads.webflow.com/5d56c24810fbfdbe08b488cd/5fbfd1a1de7eec471fcb156d_LATEST ATOM GRID installation December 2020.pdf

 

It’s clever stuff, it is a really benevolent gesture from Pilot Aware, but you have to think carefully about what it is actually showing you.

 

This is a link to their ATOM VECTOR explanation: https://www.pilotaware.com/analysis/vector

 

Best, Gaz

 

Edited December 24, 2020 by Gaznav

[RFguy]

There's a lengthy article about EC in the new Flying mag (jan/feb - I subscribe), fairly good. A few inaccuracies, but overall very good for a  (non peer reviewed) magazine article.

 

[RFguy]

Sounds interesting

Any system that uses signal strength as a range indicator is fraught with potential gross errors of most likely up to 4:1 on distance error , especially from portable from EC devices.

That's just the physics of it.

 

Using systems with time of arrival (TOA) correlators (which that one does not) , pretty good range resolution can be calculated.  Doppler systems are unlikely to have sufficient certainty because the SNR is quite low and the total pulse width is quite narrow. lots of signal is required and the doppler ring must do a full rotation within the pulse width (0.8uS) , ideally needs to be phase coherent from burst to burst

 

-glen

Edited December 25, 2020 by RFguy

[Kenlsa]

I am out of my depth here with all this tech info.

 

I yearn for the days when we looked out the windows for traffic and we used to fly low and buzz our mates to let’s them know we had arrived.

 

Ken

 

[graham brown]

Good on ya Ken I wish we could.

Gaz, not sure how we get the Airservices received distances unless we know someone. I do have contacts but it may take a while.

merry christmas

[Gaznav]

Cheers Graham, Merry Christmas to you all too. 🎄🎅👍🍻
 

There is also a few articles on this in the latest UK Flyer mag - free to view here: https://www.flyer.co.uk/electronic-conspicuity-devices-tested/ (link towards the bottom of the blog).

 

I don’t work for Flyer either.

Edited December 25, 2020 by Gaznav

[lee-wave]

I purchased SkyEcho primarily because of the 50% rebate that the CAA is offering.   All I need is to see and be seen by other aircraft that are nearby. Don't really care about aircraft more then 5 miles away or flying in controlled airspace above .  When connected to Skydemon other aircraft show as lines depicting their heading. If they present no conflict then, again, why should anyone be interested in seeing them.  More aircraft on the screen would only clutter up the display.  

[RFguy]

A battery life hint for those with Skyecho units

 

Don't leave them on charge their whole life. Charge it up before you use it. Don't charge it up and put it in the cupboard for 3 months. 

 

Batteries degrade faster if they are at maximum charge (maximum voltage etc) . Better to just put it away after use if you are not going to use it for a week or two.  Don't put it away flat though. that's no good either, put a bit of charge in, 30  minutes worth and then put it away.

 

10 to 85% is fine. but 100% is not... If you are going to store it and it is at full charge, leave it on for an hour or two then put it away.

 

-glen

 

 

 

 

[jmal]

6 hours ago, RFguy said:

A battery life hint for those with Skyecho units

 

Don't leave them on charge their whole life. Charge it up before you use it. Don't charge it up and put it in the cupboard for 3 months. 

 

Batteries degrade faster if they are at maximum charge (maximum voltage etc) . Better to just put it away after use if you are not going to use it for a week or two.  Don't put it away flat though. that's no good either, put a bit of charge in, 30  minutes worth and then put it away.

 

10 to 85% is fine. but 100% is not... If you are going to store it and it is at full charge, leave it on for an hour or two then put it away.

 

-glen

 

 

 

 

This applies to all types of batteries but more so for lithium ion batteries.  Another tip for a new device with a lion battery is to give them a good long charge; even overnight, then run them to depletion for 2 or three times.  After that, as RF suggested, charge before use and store at around 80%.  

[jackc]

On 25/12/2020 at 9:53 AM, RFguy said:

Sounds interesting

Any system that uses signal strength as a range indicator is fraught with potential gross errors of most likely up to 4:1 on distance error , especially from portable from EC devices.

That's just the physics of it.

 

Using systems with time of arrival (TOA) correlators (which that one does not) , pretty good range resolution can be calculated.  Doppler systems are unlikely to have sufficient certainty because the SNR is quite low and the total pulse width is quite narrow. lots of signal is required and the doppler ring must do a full rotation within the pulse width (0.8uS) , ideally needs to be phase coherent from burst to burst

 

-glen

I was thinking of these unit, there was one installed in my school Aeroprakt Vixxen and it seemed to work well.

 

http://www.monroyaero.com/ATD300Webpage8.pdf
 

 

[Kyle Communications]

Jack the EC uses GPS and gets the position data from the data stream put out by ADSB of the other aircraft..it doesnt use RSSI to get distance it calculates from the GPS data

 

[Kyle Communications]

That unit is RX only..the Skyecho transmits 20watts all your position data . That unit is a Stratux on steroids

 

[Thruster88]

The ATD300 has can see older mode C transponders, great. I could be wrong but the mode c has to be pinged by ground radar or a tcas before they transmit? Most of Australia has poor radar coverage at low level. I can only see less about one third of the traffic by electronic means (adsb or ozrunways)  in my area. For a lousy $12 million aud the government could give every Australian non adsb IN equipped aircraft a SkyEcho2.    

[jackc]

What I am looking for is some kind of universal solution that gives the best overall use benefits.  We have all these products with differing modes and usefulness to our requirements.  FLARM works well,  but only gliders use it and so it goes.

Nothing beats the Mk I eyeball but it’s nice to have additional methods.

the Vixxen I trained in at Coffs Harbour has the ATD-300 in it and was supplied when the plane was commissioned, so Foxbat must install them, wonder how many of these units are out there?

[Kyle Communications]

With the ADT you still need a transponder. The Vixen would have had a Mode C transponder in the aircraft. Thats the same as the Skyecho operation except the ADT uses funky software to detect the squark codes and derives angle and distance from RSSI from the older transponders. The PowerFlarm unit has similar softare to that. The Powerflarm is just a receiver..a very expensive receiver 3k

 

The Skyecho is both a ADSB in and out. It doesnt do the dectection like the ADT or Powerflarm does. I sent a email about other mode transponder detection to Uavionix and there was plans to do somethig similar but I believe they didnt go any further with that side of it because it wasnt worthwhile seeing all the other modes will be deleted in the near future and it will only be ADSB in and out used