I new to this but think this is a great project but have a few things I'm not on

[julianwebb]

This looks like a really great project and I'm planning to buy a unit when Lee has them available. Just have a few things I wonder if someone could clarify for me.

1) I've got a TRT800H which i'm planning to use for ADS-B out via my Garmin 196.

2) Then have ADS-B in via Pilot aware and also the Pilotaware in frequency on SD.

3) Transmit on the Pilotaware frequency to other PA users.

All that seems good but then there seems to be a bit of an ecosystem developing in that there is FLARM which I wont be able to see on PA but there are some systems like the TM250 which will register a FLARM signal based on signal strength so there is some warning but as PA will be on a different frequency to FLARM the TM250 unit wont see PA (unless of course they upgrade the software).

Then there are the older transponders which some people will have and not have PA. Some systems like TM250 will again register these but without a bearing but I wont be able to see them on PA (not sure if that's correct as the PA system will receive 1090 frequency?).

The PA transmissions will also be invisible to FLARM users?

If an aircraft just has PA (and no 1090 ADS-B) they will be invisible to TCAS users such as military and other public service type craft?

The PA transmissions will not be of use to NATS or airports as they will be looking for 1090 transmissions which they might use as a last resort?

It just seems that there are becoming too many different systems should PA as someone mentioned not be looking to standardize on 1090 or of course we could all voluntarily or be mandated to use PA or some other system?

My worry whichever way I look at going I'm only getting a subset of the traffic? Maybe I will need multiple systems if I want to see all the traffic is some way or another?

[Paul_Sengupta]

Not sure what this last resort thing is... 

Anyway, there are three systems as I see it (putting aside very expensive TCAS type systems):

ADS-B. Becoming a standard, but not everyone has a Mode S transponder with ES coupled to a GPS. It's reasonably expensive and power hungry to transmit. Cheap to receive and the Pilot Aware does so.

FLARM. Gliders use it, but it's expensive.

Pilot Aware. Inexpensive. Receives 1090 ADS-B. Also uses an inexpensive transmitter to transmit to other units.

If you want to standardise on 1090 ADS-B, sure, great, get an ES transponder and we'll all see you.  But if you don't want to spend £2.5k + the power and weight requirements, get a PilotAware, and we'll still all see you.

With a PilotAware, the only thing you're not seeing is FLARM. One request I put which Lee hasn't seem to have commented on is that FLARM units have a serial out connection. It would be nice to use a serial/USB converter to input this into a PAW and then send the combined info to the tablet. As far as I could see, it would be an easy thing to implement. You'd still need to buy a FLARM unit if you wanted to do that.

[Admin]

Hi Julian

Wow, a very wide ranging and detailed knowledgable text for your first posting after just joining the forum, you have certainly got yourself upto speed very quickly !

I think Paul is quite correct in his analysis regarding your confusion, but I like your approach

This looks like a really great project and I'm planning to buy a unit when Lee has them available

I presume you have already signed up for the notifications on www.pilotawarehardware.com ?
This way you are guaranteed to be notified when the stock is available.

You mention the TM250/LPAT unit in your posting, I was wondering if you have had any personal involvement with NATS or Project EVA ?

Thx
Lee

[julianwebb]

Hi Lee

No involvement with NATs and yes have got myself down for a unit when they become available. Don't think for me its a good idea to make my own (although the documentation on the site looks good to do this) better to have a system and components that are known to work.

In my case I think my ADS-B out will be my my TRT800H linked to my Garmin 196 as this has EGNOS functionality so should produce the best position data possible and the PA will then be my receiver displayed with SD (i'm hoping SD are going to make some enhancements to their software to support PA such as making aircraft below my level green, aircraft above blue and same level +- 300ft red not just all white targets with a numerical value as it is now).

If something could be done with FLARM at a date some time in the future to make a cheap FLARM receiver under some sort of license arrangement that could input to PA that would be really be great as the PA would then cover just about all targets could be detected.

Paul thanks for your reply and thinking about it a bit further I think I'm now clear.

Regards

Julian

[tnowak]

I am sure it is in the documentation somewhere, but will PAW come in two versions? TX/RX and RX only?
The reason I ask is that I have a Trig TT21 with ADS-B out (NATS validated), so I am now sending my position OUT to aircraft in vicinity.

I think I am right in saying I only need the PAW receiver capability to allow me to receive other ADS-B Out transmissions and PAW transmissions from aircraft in my vicinity for display on my SD device (by wifi)?

Thinking that, if available, a RX only PAW will use less power?

Tony Nowak

[julianwebb]

Just to add a further note to Tony's post.

Many people will already have an iPAD with a built in GPS so if the PA is receive only to an IPad with a GPS then the config of the PA will be without Tx and without GPS. Not sure if this will be available or can these be disabled in the final product?

Just as a note on Apple GPS:-  on a commercial aircraft in with my IPhone set to "airplane mode on" I can still get a good fix and track my flight all the way home with SD other Navigation software so the chip set etc must be fairly good in Apple products.

Also looking at the FLARM documentation the Antenna seems to be crucial at the type of frequency and power of PA (ADS-B should not be any problem) some glider manuals say the Antenna should not be less than a wavelength away from any type of conductor (I've got a Eurostar!) in the case of FLARM its 0.35 mtrs (see http://www.gliderdesignparts.de/weit_funkinst.en.html) so just wondering if the final product will also have an Antenna solution? FLARM do an exterior Antenna (AV-75) similar to a Transponder style for metal aircraft but its expensive - might be able to find a cheaper Transponder type exterior Antenna that covers the frequency of PA?

Kind Regards

Julian 

[Admin]

I am sure it is in the documentation somewhere, but will PAW come in two versions? TX/RX and RX only?
The reason I ask is that I have a Trig TT21 with ADS-B out (NATS validated), so I am now sending my position OUT to aircraft in vicinity.

I think I am right in saying I only need the PAW receiver capability to allow me to receive other ADS-B Out transmissions and PAW transmissions from aircraft in my vicinity for display on my SD device (by wifi)?

Thinking that, if available, a RX only PAW will use less power?

Tony Nowak

Hi Tony
There is only one version of PilotAware which is TX/RX.
The power requirement is so low, its not worth worrying about, the transmitter is less than 0.5 Watt, and with a duty cycle of less than 1%.
Which means it requires 0.5W for 1% of the time, average that out, and it is VERY low
Compare this to transponder solutions and your are looking at for example 130Watts for your TT21

There are also further developments in the aviation community which we are currently undertaking, where weight and power is absolutely critical, in this case the PilotAware application may only utilize a P3i Transceiver, in which case we most definitely want your P3i transmission in addition to your Mode-S/ES.

Thx
Lee

[Admin]

Hi Julian

Just to add a further note to Tony's post.

Many people will already have an iPAD with a built in GPS so if the PA is receive only to an IPad with a GPS then the config of the PA will be without Tx and without GPS. Not sure if this will be available or can these be disabled in the final product?

Firstly, the data that is sent from PAW to the navigation products, is relative positional, not absolute positional.
This means PAW MUST have a GPS source to calculate relative postions of other Aircraft.

More importantly, PAW provides GPS data, which means rather than buying an expensive 3G iPad, you can buy the inexpensive (I think approx £100) WiFi version  !

Also looking at the FLARM documentation the Antenna seems to be crucial at the type of frequency and power of PA (ADS-B should not be any problem) some glider manuals say the Antenna should not be less than a wavelength away from any type of conductor (I've got a Eurostar!) in the case of FLARM its 0.35 mtrs (see http://www.gliderdesignparts.de/weit_funkinst.en.html)

Antenna type and placement is crucial in all forms of radio transmission, the law of physics applies to all radio transmissions.
In the case of FLARM the output power is 10 milliwatt, this does not leave a lot of room for manoeuvre, but users regurlarly quote 1-2km
PilotAware can produce upto 0.5Watts and in our tests we are easily achieving 20km, this is more than adequate for a Traffic Awareness system, and could be reduced if required
In my ADS-B reception I can easily receive Aircraft over 150km, distances which are completely redundant in a Traffic Awareness system.

so just wondering if the final product will also have an Antenna solution? FLARM do an exterior Antenna (AV-75) similar to a Transponder style for metal aircraft but its expensive - might be able to find a cheaper Transponder type exterior Antenna that covers the frequency of PA?

We intend to offer a number of antenna solutions, which the user can decide on the best fit for their particular aircraft type.

Thx
Lee

[Moffrestorer]

There's some confusion here. PAW utilises two frequencies. It receives ADS-B In on 1090 MHz and will both transmit and receive P3i protocol ADS-B PAW originated signals on 869 MHz utilising the new "Bridge" PCB.

There was discussion on this forum some months ago, regarding the use of PAW as a ground based radar like surveillance tool for use in airfield VCRs. This adaption wouldn't require the P3i TX, because we all know the airfield is there, why broadcast a signal of an immovable object? So hopefully, Lee will be incorporating some means to deselect the P3i TX for this application.

For use in an aircraft, you will need the DVB/T Tuner dongle that essentially receives 1090 ADS-B, as a minimum, however the completed PAW unit includes the Bridge and will allow aircraft without transponder's to broadcast and receive position reports (P3i) for display on your tablet or whatever, in the same way as those received via the 1090 frequency. So for this you definitely need the P3i TX as well as RX to be functioning.

I utilise an iPad Mini with a built in GPS. I have chosen to use also, the Ublox7 GPS dongle plugged into the PAW as Lee recommends. It's as cheap as chips and works well. I use EasyVFR navigation program and it gives me the choice of using either of the GPS sources. With SD I have a feeling that you need the Collision Aware app that Lee no longer supports, to be able to use the iOS GPS source, hence the recommendation to use the GPS dongle. If I ever get to connect the PAW serial output to my Becker transponder, I shall leave the PAW in our Eurostar utilising the GPS dongle to drive the 1090 ADS-B output so we can BE SEEN even if the pilot isn't using PAW because he's using a Garmin GPS, which isn't yet compatible with PAW.

Regarding antennae positions, I have obtained good results with the PAW unit velcro'd to the P2 cockpit longeron just forward of the clear vision vent, on the Eurostar. The PAW is mounted vertically so the dongles point downwards. The GPS dongle receives good signals in this position, the P3i antenna protrudes vertically above the longeron into the canopy space so should get a clear look out to Starboard, and the DVB/T antenna is velcro'd on the same longeron adjacent to the baggage shelf. The only one I haven't been able to test is the P3i side of things. I anticipate that when the new Bridge is fitted, I may need I relocate the P3I antenna. There aren't a lot of options in a Eurostar!

[julianwebb]

Hi Lee

Thanks for your reply the relative position data is clear as is the need for the GPS dongle.

I still have one more point:-

If an aircraft has ADS-B out on 1090 and PAW out on 869 does that mean the receiving PAW will have two aircraft on the screen possibility in slightly different positions due to there being two GPS units supplying the data or does the software on PAW (or SD) only count one of the inputs as the software will have the ID of each plane?

I was thinking if there is only one version of PAW I could just remove the Tx dongle in PAW to suit my required config ie no 869 out as its not needed?

Regards

Julian

[Paul_Sengupta]

I was thinking if there is only one version of PAW I could just remove the Tx dongle in PAW to suit my required config ie no 869 out as its not needed?

It's a transceiver board, there's no separate transmitter and receiver boards, so you couldn't just remove the transmitter. You'll need the transceiver board to receive other P3i transmissions. I'm not sure if there will be a software switch in future to allow transmissions to be turned off - e.g. for a ground based receiver.

I believe that the Hex code will prevent double contacts being displayed, one for ADS-B, the other for P3i? Is that right?

[Admin]

I'm not sure if there will be a software switch in future to allow transmissions to be turned off - e.g. for a ground based receiver.

This option will be available

I believe that the Hex code will prevent double contacts being displayed, one for ADS-B, the other for P3i? Is that right?

This is correct

Thx
Lee

[julianwebb]

Lee / Paul

thanks that's clear.

Kind Regards

julian

[tnowak]

Hi Lee,

Thanks for the clarification.

So, what will I need to display the position of PAW transmitting aircraft (in my vicinity) on my SD navigation device (Samsung S3 Galaxy smartphone)? I assume just the new PAW device when it becomes available (and nothing else - no additional GPS device)?

Not sure what  Moffrestorer meant by "with SD I have a feeling that you need the Collision Aware app that Lee no longer supports....."

Also just to clarify, my Trig TT21 transmits around 130W Pulse power (I think that is the correct term).
The actual DC current drawn by the transponder when in operation is between 0.4 and 0.5A.
I only have a 12V 4.5AH rechargeable battery in my aeroplane which I have to charge at home (no aircraft charging system). I get around 7-8 hours of "flying time" out of the battery and that is powering a Becker AR3210 radio and my Trig transponder.

Tony

[Admin]

Hi Tony

So, what will I need to display the position of PAW transmitting aircraft (in my vicinity) on my SD navigation device (Samsung S3 Galaxy smartphone)? I assume just the new PAW device when it becomes available (and nothing else - no additional GPS device)?

Not sure what  Moffrestorer meant by "with SD I have a feeling that you need the Collision Aware app that Lee no longer supports....."

If you are on iOS, then you can use a GPS sharing program such as NMEA GPS
(https://itunes.apple.com/gb/app/nmea-gps/id590868529)

For Android, there were some GPS sharing programs available, in fact one of the PilotAware users developed one.

In all the trials we have performed, our recommendation will be to use a GPS device connected directly to PilotAware, either the uBlox VK-162 or VK-172
The web shop http://www.pilotawarehardware.com will offer both of these as an option.

Thx
Lee