Messages

1

OGN-R PilotAware / Re: Reduction of (number of) antennas

« on: March 07, 2021, 04:34:56 pm »

Hi Paul,

You can split at the avr-tcp level, saving yourself duplicate sdr's and decoding cpu?

Just run fr24feed on a different host and connect it to port 30002 of the ground station.

Your fr24feed.ini should contain:

reciever="avr-tcp"
host="ip:30002"

Etc

Cheers
Kev

2

OGN-R PilotAware / Re: Reduction of (number of) antennas

« on: May 26, 2020, 03:56:50 pm »

Hi Paul, a valid point, but as well as the feed up to 360 radar I use the feed for FR24 and other purposes, hence wanting to keep it a reasonably good feed.

3

OGN-R PilotAware / Re: Reduction of (number of) antennas

« on: May 12, 2020, 12:16:51 pm »

Some more info as my research improves.

Resistive splitters - the £5 satellite aerial types have a 6db + insertion loss on each output, you need a Microstrip type to get down to the 3db + insertion loss on each output.

This site was very informative:  https://www.microwaves101.com/encyclopedias/resistive-power-splitters

4

OGN-R PilotAware / Re: Reduction of (number of) antennas

« on: May 11, 2020, 08:55:25 pm »

Thanks Paul,

Interesting that you share the PAW and FLARM - I steered away from that due to the transmit on the PAW.  It has to deaden the Flarm Rx whenever it transmits anyway I suppose, but being directly connected feels like it would be worse?  Although I suppose the 2 antennas next to each other with their respective gains, vs the port isolation in a splitter - directly connected might be better!

Flarm and ADSB Rx wise I use flightaware pro dongles with the front end filter built in - the Flarm one I replaced the 1090 filter with an 868 one and that seems to work well.  Agreed I don't need the LNA for the ADSB, but didn't want to loose the 3db to 4db on the Flarm side.

Just tried it, but I get an issue that the SDR's show as a DC short - so they kill the LNA power supply, doh!  Setup without the amp for now then till I find a dc blocking splitter.

Cheers
Kev

5

OGN-R PilotAware / Re: Reduction of (number of) antennas

« on: May 09, 2020, 07:27:53 am »

P.s.  Whilst the splitter I am using is designed for 75 ohms, apparently they are not horrendous at 50 ohms, and the lna should more than make up for any losses:

https://ka7oei.blogspot.com/2019/12/using-tv-type-75-ohm-splitters-and-taps.html

6

OGN-R PilotAware / Reduction of (number of) antennas

« on: May 08, 2020, 02:26:30 pm »

So currently I have 3 antennas dedicated to pilot aware, an 868 colinear for Pilotaware, an 868 colinear for Flarm and a multiband colinear being used for ADSB. 

I need to free up the Multiband colinear for other purposes, so am going to try splitting the Flarm aerial between the adsb and Flarm dongles.

The 3db loss from the split I can make up with an LNA.  The worse 1090 reception due to a shorter and 868 tuned antenna i will have to live with - but adsb is the least of my worries given the higher power transmissions.

Any thoughts?  I will have to wait till we get some gliders back in the air to really tell the difference  of course!

Cheers
Kev

7

OGN-R PilotAware / Re: WiFi

« on: March 18, 2020, 10:37:15 am »

The OGN-R IP is 192.168.0.67 and my ssh is 192.168.0.100, so I have used the following

tcpdump -i eth0 "(not ((src 192.168.0.100) or (dst 192.168.0.100))) and ((src 192.168.0.67) or (dst 192.168.0.67))"

does this sound right ?

I don't think that s right, but struggling to get a head that feels like it is full of cotton wool around it!

To count traffic going to the Internet, you need to count all packets going to the MAC address of the gateway, whilst excluding anything going to the IP address of the gateway. 
(ie the routing table has said the next hop for the packet is the gateway, but not counting anything that is stopping at  the gateway its self - ie IGMP, ARP, RARP's, etc)

If you have other traffic going to the Internet that you don't want to count you have to exclude that too. ie if you are sshing in from a host on the internet rather than the local network.

Hope that makes sense.

Cheers
Kev

8

OGN-R PilotAware / Re: WiFi

« on: March 18, 2020, 10:29:17 am »

Ahh, I spot the problem, 'gateway' will only work if you have that name defined in /etc/hosts and /etc/ethers

You need to replace the first 'gateway' with the gateway MAC, and the second gateway with the gateway IP - ie

"ether host 06:a3:22:04:c1:71 and not host 192.168.1.1"

Cheers
Kev

9

OGN-R PilotAware / Re: WiFi

« on: March 18, 2020, 10:09:07 am »

Hi Kev
I cannot comment if this is right, not familiar with tcpstat

Sorry I just meant in relation to the amount of traffic you see on other OGN-R's?

FYI I left it running overnight on a 'traffic per hour' basis (post below was traffic per 5 seconds basis):

Code: [Select]

tcpstat -i eth0 -p -o 'Time: %S\tBytes: %N\n' -f 'ether host gateway and not host gateway' 3600
Time: 1584468258 Bytes: 21503103
Time: 1584471858 Bytes: 17313235
Time: 1584475458 Bytes: 18410907
Time: 1584479058 Bytes: 20850647
Time: 1584482658 Bytes: 13589395
Time: 1584486258 Bytes: 10110604
Time: 1584489858 Bytes: 7475430
Time: 1584493458 Bytes: 6430814
Time: 1584497058 Bytes: 5676640
Time: 1584500658 Bytes: 6181948
Time: 1584504258 Bytes: 6395193
Time: 1584507858 Bytes: 10342799
Time: 1584511458 Bytes: 11942474
Time: 1584515058 Bytes: 12832665
Time: 1584518658 Bytes: 17437069
Time: 1584522258 Bytes: 21630787

Code: [Select]

tcpstat -i eth0 -p -o 'Time: %S\tBytes: %N\n' -f 'not ether host gateway and not port ssh and not port 30002' 3600
Time: 1584468255 Bytes: 1435826
Time: 1584471855 Bytes: 1384792
Time: 1584475455 Bytes: 1444220
Time: 1584479055 Bytes: 1622926
Time: 1584482655 Bytes: 1739139
Time: 1584486255 Bytes: 1710299
Time: 1584489855 Bytes: 1578186
Time: 1584493455 Bytes: 1642774
Time: 1584497055 Bytes: 1665130
Time: 1584500655 Bytes: 1555733
Time: 1584504255 Bytes: 1604856
Time: 1584507855 Bytes: 1527436
Time: 1584511455 Bytes: 1620178
Time: 1584515055 Bytes: 1700773
Time: 1584518655 Bytes: 1584247
Time: 1584522255 Bytes: 1804454
You can see the overnight dip very nicely, going down to 5 or 6 MBytes per hour overnight, compared to 20 MBytes of so an hour during the day.  Where the local network traffic stays relatively flat at about 1.6 MBytes per hour.

But, assuming it is
Can you rerun the test with the rtlsdr-ogn service both up and down ?

Yes,

Right now. with rtlsdr-ogn running, we have about 40 KBytes per 5 seconds going out the gateway and 1 KByte per 5 seconds staying local

Right now, without rtlsdr-ogn running, we have about 14 KBytes per 5 seconds going out the gateway and 1 KByte per 5 seconds staying local

So interested to see what the 14 KBytes per 5 seconds is...  it largely seems to be port 9993 udp, which appears to be the zerotier-one VPN you use.

Stopping zerotier-one, we go down to 2 KBytes per 5 seconds going out the gateway (mainly things still trying to talk to 9993 and the ICMP port unreachable replies!) and 1 KByte per 5 seconds staying local

Did you install tcpstat, or is it in the distro ?
Also, can this count incoming packets ?

I installed it - apt update; apt install tcpstat tcpdump --fix-missing

Yes it can count packets too:

Code: [Select]

%n' the number of packets
%T' the number of TCP packets
%U' the number of UDP packets
%I' the number of IPv4 packets
%V' the number of IPv6 packets'Incoming only' could be done in the filter.

Thanks
Kev

10

OGN-R PilotAware / Re: WiFi

« on: March 17, 2020, 05:34:49 pm »

Hi Lee,

I agree, but the different in most situations (especially those where the device is connected to a 4g router) is going to be pretty small I think?

As a test. the following commands compare the Bytes per 5 second period that go out to the Internet, vs the Bytes per 5 second period that stay on the local network.  (I have excluded ssh, otherwise my own connection would skew the results, and my FR24 feed as that is pretty unique to me):

Code: [Select]

tcpstat -i eth0 -p -o 'Time: %S\tBytes: %N\n' -f 'ether host gateway and not host gateway'
Time: 1584466042 Bytes: 34579
Time: 1584466047 Bytes: 42979
Time: 1584466052 Bytes: 43568
Time: 1584466057 Bytes: 38307
Time: 1584466062 Bytes: 37375
Time: 1584466067 Bytes: 40043
Time: 1584466072 Bytes: 45243
Time: 1584466077 Bytes: 40511
Time: 1584466082 Bytes: 38741
Time: 1584466087 Bytes: 34864
Time: 1584466092 Bytes: 39435
Time: 1584466097 Bytes: 36159
Time: 1584466102 Bytes: 36023
Time: 1584466107 Bytes: 38155
Time: 1584466112 Bytes: 33608
Time: 1584466117 Bytes: 29211
Time: 1584466122 Bytes: 43107
Time: 1584466127 Bytes: 38538
Time: 1584466132 Bytes: 38678

Code: [Select]

tcpstat -i eth0 -p -o 'Time: %S\tBytes: %N\n' -f 'not ether host gateway and not port ssh and not port 30002'
Time: 1584466041 Bytes: 1332
Time: 1584466046 Bytes: 908
Time: 1584466051 Bytes: 1378
Time: 1584466056 Bytes: 682
Time: 1584466061 Bytes: 1332
Time: 1584466066 Bytes: 840
Time: 1584466071 Bytes: 1168
Time: 1584466076 Bytes: 886
Time: 1584466081 Bytes: 1649
Time: 1584466086 Bytes: 840
Time: 1584466091 Bytes: 1446
Time: 1584466096 Bytes: 636
Time: 1584466101 Bytes: 1332
Time: 1584466106 Bytes: 840
Time: 1584466111 Bytes: 1174
Time: 1584466116 Bytes: 840
Time: 1584466121 Bytes: 1378
Time: 1584466126 Bytes: 840
Time: 1584466131 Bytes: 2644
Time: 1584466136 Bytes: 1300Does that look about right?

Cheers
Kev

11

OGN-R PilotAware / Re: WiFi

« on: March 16, 2020, 09:32:20 pm »

Has anyone ever monitored the amount of data sent and received from an OGNPAW Raspberry Pi?

Hi Peter
I presume you mean going in/out of the gateway ?
Getting this at an application level is quite easy, at a system level is more difficult
Any experts here using tcpdump ?

I can imagine tcpdump can be used to monitor traffic designated to/from an external network
Extract the packet headers and accumulate the counts

Simplest to get it from the counters already on the network interface Lee?  Even ifconfig gives you Rx and TX cumulative info - 1Gb and 1.2Gb with an uptime of 5.25 days for me right now.

If you want more details, something like ntop / n load etc?  https://www.binarytides.com/linux-commands-monitor-network/

Cheers
Kev

12

Technical Support / Re: Not receiving known PilotAware and ADS-B equipped aircraft

« on: September 02, 2019, 09:31:34 pm »

Hi Lee,

I can't verify in person, but the upgrade email says it went to SW 5.2.B in May 2017.

HW 3.0, and hence can't be upgraded to v5.3 or beyond I am told.

Thanks
Kev

Hi Kev
I will email you today or tomorrow to follow up
Do you know what FW your funke has ?
Thx
Lee

13

Technical Support / Re: Not receiving known PilotAware and ADS-B equipped aircraft

« on: September 02, 2019, 06:03:58 pm »

Evening All

Sorry Peter I didn't know it was yourself at Sywell last night!

Focusing on my ADSB out for a second, there could be something wrong, but fr24 can see me near perfectly.

As we briefly said last night, my Transponder GPS feed comes from my MGL IEFIS box.  The MGL never complains about lost GPS issues.

FR24 has solid tracks for me coming back from LFAT last night, and the CSV data from them is perfect, apart from the Speed which has always jumped about all over the place.  Looks like Velocity is being calculated, but nothing else?

Timestamp   UTC   Callsign   Position   Altitude   Speed   Direction
1567352673   2019-09-01T15:44:33Z   GSLNT   50.551819,1.596581   1950   83   338
1567352679   2019-09-01T15:44:39Z   GSLNT   50.554367,1.594969   2025   84   340
1567352686   2019-09-01T15:44:46Z   GSLNT   50.556564,1.59374   2150   335   341
1567352697   2019-09-01T15:44:57Z   GSLNT   50.561222,1.591385   2325   123   343
1567352705   2019-09-01T15:45:05Z   GSLNT   50.563797,1.590199   2450   67   345
1567352711   2019-09-01T15:45:11Z   GSLNT   50.566437,1.589083   2500   87   346
1567352718   2019-09-01T15:45:18Z   GSLNT   50.568344,1.588341   2600   84   349
1567352726   2019-09-01T15:45:26Z   GSLNT   50.571304,1.587308   2675   105   348
1567352735   2019-09-01T15:45:35Z   GSLNT   50.575333,1.586151   2900   81   352
1567352742   2019-09-01T15:45:42Z   GSLNT   50.577236,1.58552   2950   70   349
1567352750   2019-09-01T15:45:50Z   GSLNT   50.580322,1.584489   3025   129   349
1567352761   2019-09-01T15:46:01Z   GSLNT   50.585106,1.582996   3175   220   350
1567352768   2019-09-01T15:46:08Z   GSLNT   50.587463,1.582103   3225   131   347
1567352782   2019-09-01T15:46:22Z   GSLNT   50.592957,1.579863   3425   144   345

Cheers
Kev

14

OGN-R PilotAware / Re: PilotAware-OGN hangs ocasionally, but ogn-rf and ogn-decode keep running fine

« on: June 05, 2019, 08:03:07 am »

Hi

As per a standard OGN-R station, 8080 is the OGN-RF status page, 8081 is the OGN-Decode status page and 80 (port mapped to 8082) is the PilotAware-OGN status page.

Cheers
Kev

15

OGN-R PilotAware / Re: PilotAware-OGN hangs ocasionally, but ogn-rf and ogn-decode keep running fine

« on: June 04, 2019, 10:03:05 pm »

Hi Pidea, port 9000 that the VRS server runs on is not exposed to the internet, just the 3 status ports.

Thanks
Kev