Are the a/c your are seeing outside your blind zone on the network?
J.
Do you know what aircraft they were that passed low overhead? Do you see aircraft on the ground? How close is the airport?
Most aircraft that transmit ADS-B do so all the time, on the ground too.
Also note that the transponder antennas on the top of the aircraft are partially shielded by the aircraft structure when seen from below, so a similar effect applies even if there is no null in the antenna radiation pattern.
3. Maybe the Doppler effect. Firstly, the plane is heading toward my radarbox so the signal's frequency is bigger: f_central + f_doppler. When it goes away, the frequency will rapidly decreases to f_central - f_doppler. Maybe the radarbox cannot adapt to this fast frequency changing.
Regarding the airport: 2 weeks ago I went with my car near the airport (200-300 m). I wasn't able to see any 'ground' plane on the Radarbox software. Only after 10 minutes after taking off. Or 10 minutes before landing.
QuoteAlso note that the transponder antennas on the top of the aircraft are partially shielded by the aircraft structure when seen from below, so a similar effect applies even if there is no null in the antenna radiation pattern.
SSR, Mode-S and TCAS use two antennas, top and bottom of fuselage.
Hi,
I've just come back from the airport :) For the low level flights (app / dep) this is what really happens:
- The tracking stops 10 min before landing. But messages are still received (at 'Changed' i can see that it changes every second). I also could see planes with 'Grounded' status. But no position report.
- Something like that happens for departing planes. Only after 10 minutes they show up on the map. Until then, only basic Mode-S info.
I have triple checked that no filter was applied. No Range/Altitude filter.
There will be a long night because right now I'm going under a pretty busy route to check again what happens when I'm right under the plane. I'll send updates, I'm taking my wireless modem with me.
Regards.
SSR, Mode-S and TCAS use two antennas, top and bottom of fuselage.
If you are not in Singapore from where the same behaivour was reported before:
Your box may not be able to detect 112 bit Mode-S signals when a certain reception power is exceeded. It seems that 56 bit signals still come through. There is a floating reference detector which may not work properly for 112 bit. I would think it is best to return the box.
Not conclusive, but I wish I had an ANRB magmount to try.
I reckon if you place the antenna on its side, you'll get uninterupted coverage over the top, but you won't get much range(well you might, but it will be perpendicular to the axis of the antenna)
I can see the planes visually they dont show up within a 10 miles radius on my radar box.
I tried an experiment, swapping the external antenna for a magmount for the ANRB.
I used my SBS-1e magmount as I've misplaced the ANRB one.
Not conclusive, but I wish I had an ANRB magmount to try.
While I agree that antennae may have a blind spot right above them this would not be an issue for this kind of traffic.
OK, we will wait with interest. Oh, by the way, welcome to the forum as I see that you are a new member. Have you only just discovered the forum?
I've got an SBS-1 too, and I ran RB and the SBS side by side for quite a while as I'd already had the SBS-1 for a year when I got my RB. Two and a half years on and I don't use the SBS at all now. I will fire it up again if Kinetic ever produce a software upgrade - lol
I didn't have any issues with a blind area with the SBS-1 either - the performance of the 2 boxes was pretty much identical, except of course for the RB network.
Where about in the world are you?
I will fire the ANRB up and connect to the network for a coup[le of days, you can see the problem for yourself. I am at S41 04.00 / E145 53.00 NW Tasmania
Mike
Do the targets show as having a position?
Hi I have had my network going today and I also have a plot from planeplotter with a few hours worth. The red circle is where I cannot receive any plots, although the aircraft remain in the list of mode-s and are continually updated, then reappear on the map when going out the opposite direction. My receive range is good, I can get up to the nsw / vic border most times.
Hi David, I only lose lat/long from the aircraft in Myflights. When you scroll across to the end of the aircraft, everything is there except lat/long. I watched a flight today taking particular note of this. When the lat/long dissapears from the list it drops off the map and the globe dissapears. Its as if it loses the ADS-B part of the messages but the mode-s is still populated for the entire flight
Mike
Hi David, I only lose lat/long from the aircraft in Myflights. When you scroll across to the end of the aircraft, everything is there except lat/long. I watched a flight today taking particular note of this. When the lat/long dissapears from the list it drops off the map and the globe dissapears. Its as if it loses the ADS-B part of the messages but the mode-s is still populated for the entire flight
Hi David, I only lose lat/long from the aircraft in Myflights. When you scroll across to the end of the aircraft, everything is there except lat/long.
there seems to be a period where direct signal is the same value as what the network is sending, so nothing gets displayed. The network coverage around London should should show more. Just a theory.
I still wonder if I have a 'null area' which I have discussed before.
there seems to be a period where direct signal is the same value as what the network is sending, so nothing gets displayed. The network coverage around London should should show more. Just a theory.
Easily tested, of course, by turning the network off and seeing if the problems persists.
I have a capture from today, how should I send it? Can I attach as a file to a post
Hi I am able to connect to 30003 and see data stream with telnet, how do I capture to a file.
Hi The aircraft in question is TGW572 - VH-VNF - 7C6C29
It passed through my no go zone at time 17.37.35
Attached is a txt file
We will investigate.
Might this be connected to the blind rectangle near New Zealand? I suggested a possible decoding error for that problem, but I don't think it got pursued any further.
http://www.airnavsystems.com/forum/index.php?topic=3452.msg33227#msg33227
Looking at the Socket Output, it is not compatible with the SBS-1 either. The last four numbers should be 0,0,0,0 as default (for false) and -1 if any of them are true.
The decoding code should probably issue an exception if lat or lon are unmappable.
Might this be connected to the blind rectangle near New Zealand? I suggested a possible decoding error for that problem, but I don't think it got pursued any further.
http://www.airnavsystems.com/forum/index.php?topic=3452.msg33227#msg33227
By this do you mean the SBS will have the same problem??
Nothing has been confirmed yet. Let us fully investigate all the details.
LAT : 54.7957 to 58.9588That's out of 112,000 lines of port 30003 output.
LONG: -8.2794 to +0.6318
Yes, and I'm certain that the ADS-B frame doesn't allow for greater than 180 or less than -180 degrees of longitude, so it was not transmitted like that.
We would ask all users reporting this problem to send us a PM so we can contact them directly with a new exe ready for testing.
Hmmm the first test is not good, no change.hi mike.
Just tracked a flight from YMLT Launceston to YMML Melbourne and lost the tracking at the same place as before
Sorry guys
Mike
The problem is that the encoding algorithm, and hence the decoding algorithm, are fairly nasty and complex.
Problem corrected (as confirmed by users in Australia and NZ).
I have the following polar diagram. Is this bug fix likely to improve it, or is it only in certain circumstances?
Or perhaps would a mast head amplifier kit improve things. My antenna is located on my balcony railing on the 13th floor of my apartment building.
Problem corrected (as confirmed by users in Australia and NZ). One step closer to V3.1 final release!
Good to hear that. Are you able to indicate what other things are being worked on? Purely for interest....
AFAIK, the other issue being worked on at the moment is spikes in the polar chart possibly caused by the real-time network.
Good to hear that. Are you able to indicate what other things are being worked on? Purely for interest....
AFAIK, the other issue being worked on at the moment is spikes in the polar chart possibly caused by the real-time network.