ADSB Grant Skyecho 2 etc

[Garfly]

36 minutes ago, kgwilson said:

I was only about 12 NM from Coffs Tower when I got confirmation of visibility the second time & I could clearly see the airport. I did see an inbound aircraft about 20 NM away but that is the limit of the software I use as it filters out anything further away than 20 NM or more than 5000 feet above my altitude. Of course receiving ADSB will depend on the power of the broadcast. If it was from a mode S equipped transponder I would assume power output would be much greater than 20 Watts.

 

Yes, good point. Just because we 'see' targets 40miles away, doesn't mean we're 'seen' at that distance.

Not that we'd need to be, by other traffic.  To be seen at a distance by ATC, though, might be useful (or not  ;- ).

The low-power of the SE2, then, amounts to a self-filtering mechanism, preventing us, the aerial hoi-polloi, from cluttering traffic displays over vast areas.   

(≈5000 sq. miles given a 40mile range).

 

 

 

 

Edited March 19, 2023 by Garfly

[RFguy]

on average, expect about 10nm line of site on transmit from a Skyecho to another Skyecho... Yep - a man's Mode S runs 200W pulse...and a good antenna.

 

Edited March 19, 2023 by RFguy

[Garfly]

That's a handy number, since many of us fly with a 10nm ring of confidence on our EFBs anyway.

 

 

 

 

Edited March 19, 2023 by Garfly

[Garfly]

1 hour ago, RFguy said:

on average, expect about 10nm line of site on transmit from a Skyecho to another Skyecho... Yep - a man's Mode S runs 200W pulse...and a good antenna.

 

Glen, so would you expect proper TSO'd ADSB-IN / CDTI gear to 'pull in' your average EC target over greater distances than, say, another EC/EFB device would?

[RFguy]

I would not expect a TSO receiver to pull in any better than a the Skyecho receiver - assuming they had the same antenna.

That's unless the skyecho implementation was suboptimal, and I would have no reason to think that it is. 

 

The skyecho ( internal ) antenna is compromised to some degree because of housing, PCB location, internal airplane bits etc

The TSO uses an external antenna but might be connected on a piece of lossy cable (but if the correct  teflon orangey stuff is used, probably not) .

 

On transmit though, the TSO device will usualyl be 200W, 10dB more than the skyecho into the known antenna, and likely to have at least 3x the range of the 20W unit. (for same antenna) 

 

Range from TX skyecho to  an air services ADSB base station should be at least  20nm  -  the ADSB base station uses gain antennas (amongst other things) .

all calcs assume optical line of site. 

-g.

 

Edited March 19, 2023 by RFguy

[walrus]

I suggest that I'm not much interested in actual distance - its irrelevant.

 

What I want to know is how many seconds I have between detection and a Skyview Audible traffic warning and between that warning and closest approach.

 

It also doesn't matter much  about you not painting the other guy - just as long one of you can see the other and communicate both ways.

 

 

[Garfly]

I'm keen to know, for instance, at about what distance an RPT (or other IFR flight) might pick me up on their fish-finder, If we discover that we're converging somewhere in Class G space.  If we each have a map view of the other's relative position it makes our radio back and forth a lot quicker and more effective.  

 

I also found it interesting that Glen reckons we're likely to have at least 20nm 'visibility'  to an AirServices base station. It helps to know that if you're in some kind of emergency situation knowing that Area can see you; it would free you up to take care of aviating.  Also handy to know even if you're just planning the safest route around tiger country (and trying to remain conspicuous).

 

I have found that even the audible alerts offered by the AvTraffic app gives you plenty of time to identify and avoid a threat.  Typically, it seems to be a good 30 secs or more.  (Although when used as a stand alone app it is subject to cell system delays, of course.)  Don't know about others.

 

Yes, if one or the other aircraft has the other on their "radar" - and they're talking - it should be okay.

 

But just knowing what to reasonably expect from this fairly new, low-cost tech seems pretty desirable to me.  Not only about 'range' but anything and everything else about it; another tool in the safety kit bag.

Edited March 19, 2023 by Garfly

[kgwilson]

The reality is that ADSB in will only be fully effective when every other aircraft is broadcasting ADSB out.

 

It would be interesting to know what the uptake has been since rebate scheme has been in place & how much of the $5 million allocated is left.

 

There have been quite a few forumites who have got them now. On our airfield there have been about 10 new SE2s purchased since the scheme began. One GA pilot who spent 5-6k getting his Modes S transponder upgraded to ADSB out has now got a SE2 for ADSB in. ADSB out is disabled in the SE2 and at $550.00 it was way cheaper than getting an installation integrated with his mode S transponder.

[Kyle Communications]

The 20nm on Airservices stuff is  nothing to bank on. I read somewhere that if you are above 5000 ft then you are more likely to be seen on  the system. But you have to remember that the 20watts is the distance limiting factor as well. Path loss  at 1090mhz is pretty high

 

On calibration part of what is done is the tech calibrates or at least checks the calibration of the barometric source that is attached to a TSO'd unit. You need  a certificate for it every 2 years 

 

[Garfly]

Yeah, well I guess we'll figure it out as we go along. It'd be great if CASA did some comprehensive field trials of EC gear and published the data.

But I don't see it happening soon.  In the meantime, little experiments like the one done by kgw (above) can help us calibrate our expectations regarding the INs and OUTs of the SE2.  Actually the IN part we can figure out for ourselves.  That evidence is right before our eyes.

 

 

 

 

Edited March 19, 2023 by Garfly

[Bosi72]

11 hours ago, Garfly said:

I'm keen to know, for instance, at about what distance an RPT (or other IFR flight) might pick me up on their fish-finder, If we discover that we're converging somewhere in Class G space.  If we each have a map view of the other's relative position it makes our radio back and forth a lot quicker and more effective.  

I fly two IFR twins and none of them have Adsb-IN as it's not required. But some pilots do carry personal "IN" devices for situational awareness.

 

All you can do as VFR is listen on Area frequency and fly at 500ft's altitudes.

[Garfly]

17 minutes ago, Bosi72 said:

I fly two IFR twins and none of them have Adsb-IN as it's not required. But some pilots do carry personal "IN" devices for situational awareness.

Yes, something to be aware of: OUT is universal but IN isn't, in commercial/ IFR aviation.

I'd still like to know how many RPTs - jets and turboprops - that venture down among the G weeds, have ADSB-IN traffic displays. 

I can't understand why they wouldn't.  

 

19 minutes ago, Bosi72 said:

All you can do as VFR is listen on Area frequency and fly at 500ft's altitudes.

Yes ... but also 'carry personal "IN" devices for situational awareness'. 

[Neil_S]

Hi folks,

 

A couple of points. 

 

Firstly if you just need ADSB-IN you don't need to spend over $1K buying a Skyecho and turning ADSB-OUT off - you can buy a PingUSB device from UAvionix for $395 (under $200 with rebate if you're quick, but still cheaper than Skyecho even with rebate). It displays traffic on your EFB same as Skyecho. You just need a power source for its USB connector from a 12V socket or portable USB battery bank.

 

Secondly I fly near Melbourne airport and frequently see the commercial stuff on my EFB several thousand feet above me. On looking up I then usually spot them (unless they're above the cloud of course). These are more than 10nm away - not sure how much further away they actually appear as I usually have my chart showing just over 10nm. 

 

Cheers,

Neil

[RFguy]

Hi Neil-  good info - 

yeah- SKyecho should see a 200W TSO Mode S  about 30nm away, if everything is goign for you 

***However for terminals right above or right below -  there is (usually) significantly less antenna sensitivity for a body mounted whip antenna above and below  - compared to our on the horizon. probably reduces the immediate up and down range by 10x  . which is rarely an issue.... once outside a 60 deg cone, you're probably less than a factor of 2 down on max range. 

Edited March 20, 2023 by RFguy

[Garfly]

17 hours ago, walrus said:

I suggest that I'm not much interested in actual distance - its irrelevant. What I want to know is how many seconds I have between detection and a Skyview Audible traffic warning and between that warning and closest approach.

This got me to wondering what the industry standards were in that regard.  I found these tidbits interesting:

 

https://www.ifr-magazine.com/training-sims/flight-traffic-displays/

 

"TCAS is the touchstone that all systems reference. It interrogates surrounding transponders much like ATC secondary surveillance radar. The system must have a 14-mile range, but most extend to 40."

 

So the range of our SE2s is not so shabby, after all; at least in their primary (air-to-air) role and at our relatively leisurely closure rates.

 

Regarding Traffic Advisory standards:

 

"Proximate traffic is within six miles and 1200 feet, but not a threat. TAs and RAs are based on a closest point of approach (CPA) based on time. (Provisions exist for slow closure rates.) An aircraft with a CPA of 20-48 seconds sets off a TA, with higher altitudes yielding the longer times. A target with a 15-35 second CPA sets off an RA in TCAS II."

 

And regarding CDTI (Cockpit Displays of Traffic Information) standards when TCAS info is combined with that of ADSB et al:

 

"TCAS, TAS, and TCAD follow the same display scheme. TIS adds a vector showing an aircraft’s ground track in 45 degree increments.

ADS-B mixes things up. Traffic display standards for ADS-B traffic relay directional information by using an arrowhead symbol in either white or cyan. An altitude climbing or descending arrow, a directional vector line extending from the point of the arrowhead, and call sign are also shown for ADS-B Out traffic.

 

Non-ADS-B craft show as “Pacman” symbols with altitude and climbing/descending arrows provided by TIS-B. Ground traffic displays as brown/tan. Ground vehicles are also brown/tan as a top-view rectangle with “wheels” that take some imagination to see.

Combining TCAS or TAS with ADS-B modifies the display of traffic. Non-ADS-B Out traffic will be depicted using standard TCAS symbology. Display of traffic with ADS-B Out will show new symbols combining the arrow head into either an amber circle for a TA and red square for an RA."

 

 

 

 

 

Edited March 20, 2023 by Garfly

[kgwilson]

6 hours ago, Neil_S said:

Hi folks,

 

A couple of points. 

 

Firstly if you just need ADSB-IN you don't need to spend over $1K buying a Skyecho and turning ADSB-OUT off - you can buy a PingUSB device from UAvionix for $395 (under $200 with rebate if you're quick, but still cheaper than Skyecho even with rebate). It displays traffic on your EFB same as Skyecho. You just need a power source for its USB connector from a 12V socket or portable USB battery bank.

 

6 hours ago, Neil_S said:

 

 

 

Cheers,

Neil

Personally I think that the SE2 is a better buy even at twice the price of the Ping USB as there is no mucking around with cables as you may have your tablet connected or need dual USB power outlets etc & ADSB Out is there if your Mode S ADSB Out fails for any reason & if you have another aircraft without ADSB Out you can use it in that.

Enroute software filters out all the RPT more than 5000 feet above and everything more than 20NM horizontally so as to reduce clutter on the screen which I think is a good idea. I don't care about other traffic if it has no potential threat.

Edited March 20, 2023 by kgwilson

[Ironpot]

On 20/3/2023 at 6:37 AM, Bosi72 said:

 

All you can do as VFR is listen on Area frequency and fly at 500ft's altitudes.

I overheard a interesting one the other day:

R75** sailing along at 7600 ft in class G on an IFR route clearly not listening out on Area frequency. ATS warned-off IFR traffic flying at 8000 and they manoeuvred to avoid R 75** using ADSB in. 
How good is that?

[RFguy]

system works.

WHAT SHOULD have been done  or could have been with the ADSB integration  was a method to alert the pilot  to pay attention - return Mode S. 

IE like Sellcall function for 2 way radios.

something flashes and beeps. the system supports this in Mode S.

I think my Garmin GTX335 does.
Wonder what sort of device R75** was using ?

[Garfly]

2 minutes ago, RFguy said:

Wonder what sort of device R75** was using ?

Yeah, me too.  If it was just a SkyEcho2 (as opposed to a proper Mode S/ES transponder)  it would show that the system is working - even for we, the masses.   ;- )

[kgwilson]

2 hours ago, Ironpot said:

I overheard a interesting one the other day:

R75** sailing along at 7600 ft in class G on an IFR route clearly not listening out on Area frequency. ATS warned-off IFR traffic flying at 8000 and they manoeuvred to avoid R 75** using ADSB in. 
How good is that?

Now if the IFR traffic had ADSB in they would have seen R75** and ATS would not need to intervene. 

 

When ADSB out was mandated they should have also mandated In as well. OK additional cost but short sighted as it will be more expensive to instal it later.

Edited June 9, 2023 by kgwilson

[RFguy]

but, ATC provides separation for IFR and VFR traffic for IFR traffic , that's their job (putting aside if all the planes had been equipped, then the two planes could have alerted their pilots without ATC) 

[Ironpot]

16 minutes ago, RFguy said:

but, ATC provides separation for IFR and VFR traffic for IFR traffic , that's their job (putting aside if all the planes had been equipped, then the two planes could have alerted their pilots without ATC) 

Correct.

ATC alerted the IFR aircraft, they requested and were cleared “up to 5 miles left of track” ; announced he could see R75** on the ADSB and once they were abeam of R75** they simply tracked to rejoin planned route. 
ATC were using radar.

 

 

[Ironpot]

I understand that very few RPTs have ADSB in.

[Markdun]

That doesn’t seem correct. When ADSB was first being introduced the RpT industry (Q &V) were prepared to pay Airservices for all aircraft to have ADSB out fitted for ‘free’ to the aircraft owner on the basis it would save them more money in fuel savings particularly at regional airports, ie based on then using ADSB ‘in’ to avoid recreational and charter aircraft etc. The recreational side of aviation like GFA and RA-Aus were apoplectic with rage that this would herald in Big Brother and every RA-Aus flight would end with 3 AFP vehicles a CASA inspector and the arrest of the RA-Aus pilot on terrorism charges to be tried in a secret Star chamber court.  The GFA has concerns that no glider could thenforce ever climb a thermal because of the mass of the battery to power the ADSB device.

Oh, how times have changed.

 But I’m happy to concede that perhaps RPTs didnt fit ADSB in because without the surety that all aircraft have it, what’s the point?

I fitted the SE2 after having the shit scared out of me by a heavy military helicopter travelling in the opposite direction to me at my altitude while I was downwind 1000’agl in class G airspace. We missed by about 250m. They weren’t on the area Frequency. My subsequent follow up communication with them indicated they rely solely on ‘see & avoid’, ie roulette, but ‘usually have the ADSB turned on’.  And the SE2 has been fantastic for avoiding them since.

[skippydiesel]

Whats going on - no less than 3 separate SkyEcho discussions at once - cant they be combined?