Messages

16

General Discussion / Re: My Pilot Aware arrived today

« on: May 18, 2016, 09:49:51 am »

Not working.     Have got as far as plugging in power and the Pi doesn't appear to be starting.  Instead of getting alternating red/green lights they're both permanently on.  Also lacking the 4 screws to hold the Pi together; I'm sure I can get over that!  Ideas on the startup would be appreciated though.

Dave if it was me I would plug in an HDMI cable in the port on the Pi so it can display the boot sentences on the TV screen - if any. That would give you something on progress assuming the Pi is getting that far.

I would also unplug the USB bits and see if the PI boots on its own.

Might be also something silly like the power pack not giving enough juice out.

Others may have alternate suggestions.

17

General Discussion / Re: GPS Ublox7 Dongle connection problems

« on: May 18, 2016, 09:25:12 am »

I'm having the same problem as described.

I'm using an iPAD. UBlox GPS showing as available and receiving messages but no mode or satellites or at best 2-3 satellites. No flashing green light indicating GPS lock.

The GPS I'm using is the standard UBlox and was working on previous version of software but seem to have problems now.

Power supply and cable provide 2.4amp capacity so don't think that is the problem.

Screen shot posted direct to Lee as too large to attach.

Alan

18

General Discussion / Re: When willl the PAW be ready?

« on: May 13, 2016, 12:22:19 pm »

Thanks Lee. Email sent.

Alan

19

General Discussion / Re: When willl the PAW be ready?

« on: May 12, 2016, 10:47:56 pm »

Thank you Keith I think I see what you are saying.

In summary if you were a beta licence holder you can upgrade you licence to allow the new software on a Pi B+ and this will function with, or without, the new bridge until May 17.

The two new features of Audio and Mode S detection will not function on the Pi B+ and the extended beta licence will not be transferable to a Pi 2B should I already have the hardware.

When will the old licences based on the Wifi be added to the database please as I submitted an email to your support email last night and have just tried again to obtain an upgraded beta licence but I get an error message that the licence codes I entered are not associated with the email address I entered.

Regards

Alan Burrill

20

General Discussion / Re: Not sure I have been sent extension Licence for ARF Replacement Purchase.

« on: May 11, 2016, 12:29:28 pm »

I have received no email either and have a couple of old keys.

I already have a Pi2B and would like to try  the new software/hardware combination on ADS-B before committing to the new bridge.

21

General Discussion / Re: I new to this but think this is a great project but have a few things I'm not on

« on: April 01, 2016, 09:36:54 pm »

I'm sure I've read in a number of places that NATS do not (will not?) make any use of our ADS-B 1090Mhz ES transmissions. Conversely, CAP 1391 section 6.12 says the ANSPs (NATS) can use 1090 ES from an EC device for visibility of GA. I'm a trifle confused by the apparent contradiction.

NATS do not currently provide the 1090 ES date to ATC although they have a system on trial across the south of England which currently is receiving and recording ES data for analysis and has been used to validate and analyse those transponders that have been used to broadcast non certified GPS position date.

The ES data is additional to the Mode-S response that is transmitted by the transponder and the Mode-S data also Contains the aircraft ICAO address codes as well as the Aircraft I'd. ATC do have visibility of the Mode-S data hence they are able to see your Callsign if you have the SSR Monitoring SQWAK set and they want to talk to you because you are telling them you are monitoring that frequency.

There are currently some countries, mainly where conventional radar sites are few and far between, where ADS-B is used by ATC and I have seen these in my professional travels, I used to work for NATS.

Currently in Europe the only country that mandates a Mode-S transponder with ES is Holland for their North Sea operation where radar is unable to provide the low level coverage. I am am sure, personal opinion,  that will change as the reliability and integrity data for the ES information is gathered and demonstrated to provide information to meet ATC requirements.

Hope that helps

Alan

22

General Discussion / Re: New CAA low power portable ADS-B device spec

« on: March 29, 2016, 09:55:05 am »

But you are sending it in your E.S transmission.

That's correct John, but as NATS/ATC apparently can't receive ADS-B outside the south east of England, being able to get your call sign from your Mode 'S' transmission is essential for the listening squawk system to work properly throughout the rest of the U.K.

Regards

Peter

Currently the ES element of the Mode-S transmission is not used by NATS in an Operation capacity in any location.

The Mode-S element sent in response to a ground interrogator contains two elements. The conventional A/C response with additional data fields on the end containing the Hex Code, Aircraft Id etc

The ES element of a Mode-S transponder is broadcast from the transponder and is a data message. The timing is set to ensure that the transponder response to a ground interrogator is not overlapped with an ES broadcast response.

If I may go back to the original issue regarding the use of two devices simultaneous transmitting the same aircraft id. We are both making individual interpretations of what we have heard and what is written. The ultimate deciding factors is the response from the CAA and if what has been published so far, or is in the public domain, is being interpreted differently then it needs clarification and I suggest that feed back to the CAA is necessary to sort this issue.

23

General Discussion / Re: New CAA low power portable ADS-B device spec

« on: March 28, 2016, 02:12:07 pm »

This thread is seeming like a moot point to me.
PilotAware is most definitely not 1090 ADSB out.

All this talk of one device etc etc may be pertinent to whether LPAT is compatible with a transponder, but I fail to see how it is pertinent to PilotAware.

With PilotAware you can SEE any of these other ADSB devices, you can BE SEEN if you have a mode S transponder and you connect PilotAware to it to give ADSB out (or indeed any GPS, but what's the point in doing only that, you can't "SEE" if you just connect GPS to your transponder) and you can even BE SEEN and SEE other PilotAware users.

Nothing wrong with what you state.

As I have posted earlier the use of electronic conspicuity devices is going beyond the old PCAS and FLARM units and equivalent and is in its early stages.

There is a lot going on in the development of he standards headed by the CAA and sponsored by Europe through Project EVA and the start of this thread highlighted the CAA CAP Document for those wishing to read, and comment as they desire.

I suggest that as operators of small light aircraft we only have room and money for one device and therefore we want value for money in a device that provides maximum visibility of others in the airspace and provides the maximum visibility of us to others.

Users have a choice of devices and I have no allegiance to any.

24

General Discussion / Re: New CAA low power portable ADS-B device spec

« on: March 28, 2016, 12:43:19 pm »

Just a thought then....

My Mode S transponder has a switch that allows me to have Mode A, Mode C and Mode S. If I select Mode C (Actually Mode A and C) then I will no longer be sending my Hex and A/C I.D. Then I could switch on my LPAT and would also be sending my Mode S E.S data allowing much more information to be sent than with the Mode S on my Txpdr.

Also - if the spec says "only one device using" then isnt that still the case when the Mode S transponder is sending its burst of data, it is "using" the i.d and then when the Lpat sends its millisecond(s) burst - it is then "Using". Ok, occasionally they may both transmit simultaneously and produce fruit but it wont be decypherable.

John

Reading the now published CAA document I believe the following applies

Have you a link or CAP number for this please.

As Steve has pointed out the first post in this thread points to the CAP document and the opportunity to comment.

My own transponder is either on or alt with no option to disable the Mode-S features. I would also suggest that disabling a perfectly good Mode-S transponder would remove the advantage of providing ATC with your aircraft Callsign which aids them contacting you either on receiving a service or using a listening squawk.

The Hex code in the Mode-S response aids correlation in the plot extractors and display software and having multiple transmissions from the same target must all be processed, see the CAP document explanation, increasing the amount of fruit and time to determine the correct target and position.

Mode-S is a means of reducing fruit on the frequency by allowing selective interrogation in high density target areas using the ICAO Hex code. Deselecting that feature means that only an All Call from the ground interrogator will get a response form an A/C transponder. That together with MonoPulse all provides a greater integrity of target reasonsolution and verification allowing the reduction of separation criteria in areas where Mode-S predominates. So there are many factors to consider in this debate - but it is a debate and currently only my opinion based on my knowledge and experience.

In my view if you have a Mode-S transponder then having the ES option enabled with a GPS output would be my preferred option as then I would only be concerned about having a device that is listening for other targets.

25

General Discussion / Re: New CAA low power portable ADS-B device spec

« on: March 27, 2016, 11:15:31 pm »

I have read on several posts that it is not permitted to have two devices that transmit on 1090Mhz in one aircraft installation. May I ask where this rule is written please.

I don't understand the technical reason either.

The Mode S transponder is an interogation led device, i.e it gets interogated on 1030mhz and replies on 1090Mhz.

The ES transmission occurs pseudo randomly on 1090 with the ADSB data.

Where is the conflict ?  Can they not co -exist. Is it a worry that the two transmissions ( on some occasions) may overlap?

Reading the now published CAA document I believe the following applies

There shall be only one device using the ICAO aircraft address therefore;

If you have an A/C transponder with a low powered ADS-B device then only the ADS-B device will be broadcasting the ICAO aircraft address. In my interpretation that means I could have both devices operating.

If you have a Modes-S transponder with no ES output the Mode-S device will also be transmitting the ICAO airactft address and therefore only one device can be used.

If you have a Mode-S transponder with ES and a GPS connected then you would not need a separate transmitter as you would already be broadcasting your position as an ADS-B output via the transponder.

That is my interpretation of the published documentation and effectively I am interpreting the published information that the ban is effective on using a 1090 ADS-B out device in conjunction with a conventional Mode-S transponder with no ES and a Mode-S ES transponder you would not need a separate ADS-B out device anyway.

I was assisting NATS and AOPA during the trails of the LPAT and we asked all volunteers to switch off their transponders at the request of the CAA and NATS to ensure no cross interference during the trial.

This is my interpretation and I have already raised this with the CAA conspicuity working group as a Member of the FASVIG Conspicuity working group for a clear understanding as it is creating a good deal of conversation and needs to be closed down.

As a former radar engineer I have a clear understanding of the issues and why it's essential that the data to ATC systems is not compromised especially where maintaining separation of traffic is required. However I also believe the issue can be addressed and a better picture provided.

You have to appreciate that these devices and the rules around their use are in their infancy hence questions like this will arise and therefore good positive feedback is necessary to clear these issues. I hope you will also response to the CAA consultation on the low powered ADS-B specification so they are recorded through that mechanism.

Hope this helps.

Alan

26

General Discussion / Re: PilotAware users.... NATS would like your help.....

« on: March 19, 2016, 05:45:56 pm »

Hi Steve,

Last email received from Adrian Price of NATS contained info on the tests of LPAT that he is hoping the volunteers will perform. I'm not clear how having just having PAW with ADS-B In sits with this? I'm guessing both test airframes are expected to carry loaned LPATs.

Adrain will have a plan in mind but the last flight i did with them was my ADS-B out Trig and PilotAware in with an LPAT in the other Aircraft. what we were looking for is interaction of LPAT with ADS-B out and Pilot Aware with an LPAT ADS-B Out.

There are other instances for example LPAT will detect A/C and also FLARM as well as Power FLARM will detect ADS-B out and, I believe, also detect ADS-B in from the LPAT.

Overall therefore Adrian will be looking at multi device interaction to demonstrate LPAT performance against other devices.

So if you have a Transponder and and ADS-B in device, or even a traffic awareness device or FLARM then this will be helpful.

At then end of the day down to Adrian.

Hope that helps.

Alan

27

General Discussion / Re: Mode A and Mode C

« on: March 02, 2016, 11:19:31 am »

There needs to be a contact to equip all military aircraft with a PAW... 

I doubt they'd use it for the same reasons they generally don't carry ADS-B out.

Alan

28

General Discussion / Re: Is LPAT actually available?

« on: February 18, 2016, 05:21:58 pm »

Rob,

I have be been working with the NATS and AOPA and I can confirm the the NATS LPAT is currently not in production. The devices currently under trial are demonstration kit.

Kind Regards

Alan

29

General Discussion / Re: Mode C/S

« on: December 26, 2015, 04:04:02 pm »

One reason for this is that the transmitter of transponder 1 would blow up the receiver of transponder 2 and vice-versa, since they are operating on exactly the same frequency

Mmmm. Transponders transmit on 1090Mhz but receive on 1030Mhz so can't see any blow up caused by that.

Anyway our £5 dongles that do listen on 1090 seem to cope just fine

I think NAT's issue re LPAT  is garbling though that happens to some degree anyway. I wish they would at least try both transponder and LPAT ADS-B out together in their ongoing trail and see if it 'just works' in real life. .  It would save a lot of us shelling out to upgrade our MODE S to add ADS-B.

I'd like to understand how NATS can tell if it is one of two devices transmitting anyway.

As Ive done quite a lot of the Flying with LPAT on behalf of AOPA and NATS perhaps I can input some thoughts.

Not using the Aircraft Transponder during flying of the LPAT was defined by the CAA to avoid interference, garble and FRUIT, from the LPAT with the conventional Mode-S and A/C Transponder. It has not been determined scientifically that the LPAT would cause problems with the conventional ground interrogations/response but a precaution that was implemented as part of the CAA authorisation to conduct the trials.

In my particular case the need to switch of my Transponder is a more of a practical issue with that fact that I also have an ADS-B enabled transponder hence during the flying trails we needed to be confident that the ground tracking of the LPAT and receipt by an LPAT in another aircraft was from the LPAT transmissions. In addition we needed to be certain that any onboard transponder was not flooding the Rx of the LPAT and affecting range performance of the LPAT Rx.

Overall the trials of the LPAT are being done in an environment to determine the performance of the LPAT and therefore eliminate any possible effect of a working transponder in the same aircraft. In addition the CAA authorisation for the LPAT is for only one working transponder in the aircraft undertaking the trials.

Having said all that Im sure I have had both operating together, pure accident, and not had any reports from ATC that I have disappeared from their radar :-) but nothing formally tried and perhaps we need to include an LPAT flight with an active transponder to determine if LPAT performance is affected on the RX side. As you suggest a well designed Rx should be able to cope with a nearby Tx on the same frequency within limits as my onboard PCAS as well as other existing traffic warning devices demonstrate.

Ref the discussion on the use of two active Transponders in the same aircraft i.e. Conventional and/or LPAT. This would produce interesting results if they both would respond to ground interrogations, the LPAT does not respond to conventional Ground Interrogations, as the Radar Display Trackers would see two response from a target. At the moment the ADS-B position data from the Uncertified GPS enable Transponders and LPAT, is not sent to any of the Radar Tracking software but only recorded so in this safety conscious environment it can be determine if the accuracy, reliability and integrity of the ADS-B transmissions from uncertified GPS is sufficient for presentation to ATC either on its own or as part of a combined Conventional Transponder, ADS-B enable environment. In the future - lots of work still to do and part of the overall European Trials of uncertified ADS-B enabled transponders, including LPAT, I'm sure this is the direction that it will go in Europe and is already part of the overall surveillance environment in other countries where conventional SSR ground Stations are challenged by terrain and other factors.

All of this is part of a European Project EVA which is looking at the use of Electronic Conspicuity devices to assist the VFR pilot. You can read more of this in the AOPA magazine.

Merry Christmas and a Happy New Year..

Alan

30

General Discussion / Re: Serial logic levels for Funkwerk TRT800 Mode S txpdr

« on: December 07, 2015, 12:46:59 pm »

If + - 5v then the need for an RS232  level shifter goes away and one could chop about a standard USB lead and find the Pi TxData out and use that as the data source for RxData in to the Txpdr.

Anyone know ??

John

John

USB and RS232 are two different standards and, if I'm reading you post correctly. simply using the Tx pin on the USB port to drive the Rx in port on the Transponder is not going to function. It's not all about the volts..

You would still need the USB to RS232 converter. Its not unusual for the RS232 voltages on an interface to be +/- 5v specified as the tolerance in the standard is a little flexible in implementation.