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APRS police on warpath

VHS

Well Known Member
The following post appeared on the APRS Yahoo Users' group ( followed by my defense of you guys), so if any of you know this evil-doer, please have a friendly chat with him!

If anyone knows VLADYSLAV V KARPAYEV from BAYONNE, NJ he could use some guidance. He is proudly showing off his RV-9A kit plane to the mid atlantic area. He even put a SSID on his airplane tail number N666BK-1. There is an individual that will be trying to post a note to the vans airplane forum to let them know that wide1-1 is bad for the aircraft. It seems like the vans group has decided that Automatic POSITION reporting system is great so those that are at home can track them "for safety". I am not anti-aircraft or anti-tracker but if the vans groups keeps up with the attitude of "get your tech license and get a tracker in your kit plane" and beacon away the airwaves APRS is going to be useless! They are just careless and apparently don't know how much damage they are doing.

WIDE1-1,WIDE2-1 and every 10 seconds is just WRONG from an aircraft!

end of the rant...

Carl,KB1EJH


73,

Allen
VHS
 
The following post appeared on the APRS Yahoo Users' group ( followed by my defense of you guys), so if any of you know this evil-doer, please have a friendly chat with him!

If anyone knows VLADYSLAV V KARPAYEV from BAYONNE, NJ he could use some guidance. He is proudly showing off his RV-9A kit plane to the mid atlantic area. He even put a SSID on his airplane tail number N666BK-1. There is an individual that will be trying to post a note to the vans airplane forum to let them know that wide1-1 is bad for the aircraft. It seems like the vans group has decided that Automatic POSITION reporting system is great so those that are at home can track them "for safety". I am not anti-aircraft or anti-tracker but if the vans groups keeps up with the attitude of "get your tech license and get a tracker in your kit plane" and beacon away the airwaves APRS is going to be useless! They are just careless and apparently don't know how much damage they are doing.

WIDE1-1,WIDE2-1 and every 10 seconds is just WRONG from an aircraft!

end of the rant...

Carl,KB1EJH


73,

Allen
VHS

Allen,

Thank you for taking the bullet for us! I hope you don't mind me posting your reply to "Carl", if you do let me know and I'll delete it.

Carl,

If you take a look at the Van's RV APRS discussion page, you will see the recommended configuration profile at the top sticky. I don't see anything wrong with people getting a tech license to put a tracker in their experimental aircraft, or operating a tracker from an aircraft responsibly. The Van's site is probably the most sensitive group about appropriate use of APRS in airborne op's, and not everyone who owns or is building an RV gets their information from that site. No one on the Van's site would argue that this users settings are anything less than abusive, and I know that neither Byon or I would ever program a Micro-Trak or TinyTrak with those kind of settings. It sounds like we have someone who needs a little education, but has his heart in the right place.

Allen, AF6OF
VHS/BYONICS


Yes, we want to be responsible citizens in the APRS community, maybe this will serve to raise awareness. Carl's post also sounds like another example of hostility from the 'haters of the no-code Tech license' portion of the ham community. :)
 
If "Carl" is reading this, call me at 1-201-253-9121, I want to talk to you.


Thanks Allen.




Allen,

Thank you for taking the bullet for us! I hope you don't mind me posting your reply to "Carl", if you do let me know and I'll delete it.

Carl,

If you take a look at the Van's RV APRS discussion page, you will see the recommended configuration profile at the top sticky. I don't see anything wrong with people getting a tech license to put a tracker in their experimental aircraft, or operating a tracker from an aircraft responsibly. The Van's site is probably the most sensitive group about appropriate use of APRS in airborne op's, and not everyone who owns or is building an RV gets their information from that site. No one on the Van's site would argue that this users settings are anything less than abusive, and I know that neither Byon or I would ever program a Micro-Trak or TinyTrak with those kind of settings. It sounds like we have someone who needs a little education, but has his heart in the right place.

Allen, AF6OF
VHS/BYONICS


Yes, we want to be responsible citizens in the APRS community, maybe this will serve to raise awareness. Carl's post also sounds like another example of hostility from the 'haters of the no-code Tech license' portion of the ham community. :)
 
I think "smart beaconing" triggered all this anger. I was assigned pretty tight test area and to get to altitude I have to do constant climbing turns between busy intersections. I think it's unique situation and it is probably a good idea to disable smart beaconing during Phase One. I took the tracker for reprogramming tonight. Would appreciate any suggestions.


These are current settings.



beelineGPSsettings.jpg
 
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Vlad, as i understand it the path Wide 1-1 will cause unnecessary repeating. Have you tried disabling the path Wide 1-1 and just using Wide 2-1?

Also, it looks like when you're going over 60mph (almost any time you're in flight) you'll be beaconing every 60 seconds regardless of whether you're turning or straight and level. A least that's what the settings look like to me.
 
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Vlad, as i understand it the path Wide 1-1 will cause unnecessary repeating. Have you tried disabling the path Wide 1-1 and just using Wide 2-1?

It was mentioned by couple of my friends but I didn't get a chance to remove it. The tracker was beeping in my MINI for nearly two years and nobody said nothing. I always appreciate education.
 
Sam,

I am thankful you've spent so much effort helping us understand the APRS setups and how to configure them for the best balance of performance and behavior.


Allen,

I PM'd Vlad earlier today when I was emailed direct from Carl. I had a similar "experience" a few weeks ago. In my case, I had just upgraded my antenna and didn't realize the huge improvement in coverage. Byon from Byonics.com contacted me with some configuration suggestions and I corrected the error. You guys at Byonics have been great. Thanks!


All,

I agree there is a bit of friction but I do not feel it is wide spread in the APRS community. My hope is that, when anyone has the opportunity to pass along education (HAMs, pilots, builders, etc), we strive to do it in the spirit of cooperation and benefit for the communities at large. My experience has been just that and I'm thankful for that.

(sorry if that sounded a bit like a sermon for "let's all play nicely in the sandbox")
 
It was mentioned by couple of my friends but I didn't get a chance to remove it. The tracker was beeping in my MINI for nearly two years and nobody said nothing. I always appreciate education.

Vlad,

WIDE1-1 is recommended for ground vehicles because the range of your tracker while on the surface is very short in congested areas. But the same tracker when airborne can transmit to the horizon.....which is a fur piece.

WIDE1-1 as part of the airborne path might be fine for areas of the country that have sparse digi populations but the New Jersey area is sorta congested and has a lot of digis and iGates. WIDE2-1 should give you excellent service in your part of the world, it works nicely in mine as well.

A simple config change will make your tracker a polite neighbor but pacifying crusty ol' hams who resent the new guys on the block is a bigger challenge. ;)
 
Copy that Sam. Could be a market for Byon :) trackers for congested areas, over desert, sea etc.
 
Copy that Sam. Could be a market for Byon :) trackers for congested areas, over desert, sea etc.

Vlad, your tracker can already accommodate that ideal. That is what the secondary profile in your tracker is for--all you need is a switch to change from 'city' config to 'boondocks' configuration. Set the city config with WIDE2-1, and the boondocks config with WIDE1-1, WIDE2-1. You can also have different SmartBeaconing settings for each profile.
 
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Another idea I emailed to Byon was the possibility to have the profiles switch based on speed. Given the programable firmware, it may be possible. Profile 1 could be for ground ops and profile two would switch at a given speed. That way, not only could the beaconing rate change but also he WIDE settings.
 
I plead guilty to Wide 1-1 as well. Much of my flying is done over sparsely populated areas and the only way to get coverage is Wide 1-1 (see my note in the "setup sticky" discussion. I would appreciate if someone with a bit more knowledge of all this would have a look at my recent tracks (N7965A - try either today or last Mon/Tues 18/19) and see whether there are "too many" packets going out and congesting the system. If this is the case, any suggestions for some sort of compromise where I might still have the utility of reaching secondary stations but not overloading the system?

thanks,
greg
 
Many hams tend to really overreact when someone goes overboard on transmission intervals and extra-wide digipaths.There is no hard and fast rule, but I try to error on the side of conservatism ( Of course, I make Ronald Reagan look like Trotsky, so that's sort of my natural inclination) but its not the hill I want to die on. A simple e-mail or phone call generally clears it up easily and its not worth burning up stomach lining worrying about one guy eating airwaves. For a lot of Hams, APRS is their whole world, and they spend their days watching raw data go by looking for offenders. Very sad when they could be in the sky sending dots.......

Now that Byon is using a PIC with twice the computing power and storage capacity of the old TT3 in our MT-RTG FA and our MT-AIO ( with upgrades for older models still on the to-do list) We agree that allowing the tracker to switch to a separate configuration based on altitude is the simplest way to handle the problem. A good mobile path on, or close, to the ground, and a more conservative path and rate at altitude should keep everyone happy.

I still like the idea of finding the cheapest way to set up I-gates and getting as many people as possible (with frequency agile equipment) in aircraft and meteorological balloons to use another frequency when flying at altitude. The horizon is pretty far away in most of America at 5000 feet....., and hitting I-gates at very low power at ranges of hundreds of miles is common. Even a small percentage switching over to an alternate frequency could take a big load off the RF "National" infrastructure.

Allen
VHS/Byonics
 
The horizon is pretty far away in most of America at 5000 feet....., and hitting I-gates at very low power at ranges of hundreds of miles is common. Even a small percentage switching over to an alternate frequency could take a big load off the RF "National" infrastructure.

Just don't do something negative for those of us who will be 1000' or more under ground at 5000' MSL. I am at the low end of my flight regime at 10,000' MSL. :)
 
Ron,

It would have to be a user settable function; People in Denver would need far different settings than us sea-level people!

Allen
 
You could sort of estimate height above ground by noting the altitude you were at when you were last moving at non-airplane speeds, and assuming that's how high the ground is. Obviously this would work less well for a flight between two different elevations or a flight from the flatlands over the mountains, but it's something. There are a variety of tricks to it.

Or... portable Garmin aviation GPS units with terrain databases can output the aircraft's current height above the local terrain elevation in the $PGRMH NMEA sentence. That's a more reliable way to know height above ground.

mcb
 
Allen,

For airplane use, could the RTG firmware switch based on speed rather than altitude as I noted above? That would work for any airplane anywhere and also work during cross country flights. Is there a way to key off of the GPS derived speed?
 
If someone will tell me exactly what I need, I will put up an I-gate in southeast alabama. I just do not have any time for a research project.

N4IDH, and yes, I did the code test @ 13 WPM (A very long time ago, but I still know it).
 
I plead guilty to Wide 1-1 as well. Much of my flying is done over sparsely populated areas and the only way to get coverage is Wide 1-1 (see my note in the "setup sticky" discussion. I would appreciate if someone with a bit more knowledge of all this would have a look at my recent tracks (N7965A - try either today or last Mon/Tues 18/19) and see whether there are "too many" packets going out and congesting the system. If this is the case, any suggestions for some sort of compromise where I might still have the utility of reaching secondary stations but not overloading the system?

thanks,
greg

Greg, I'm still learning all this too. Look at your raw data herehttp://aprs.fi/?c=raw&call=N7965A&limit=500&view=normal From what I can tell, you have an average of a packet being received every 22 seconds. With all the red lines in there, it looks like some parameters need to be changed too. Perhaps someone who is way smarter than me can chime in and add some enlightenment.

As to comment about the relative subject of this thread, I was a HAM operator long before I got involved in APRS or Van's aircraft tracking. Emergency communications got me into Ham radio. In fact it was a "phone patch" call by a frind that really got me interested. That's all but archaeic nowadays. I think a lot of hams have gotten away from "helping pass knowledge" and have gotten more into a " policing the airwaves" state of mind. Whether they want to accept it or not, Ham radio is a dying past-time. Encroachment on our allocated frequencies is ever present and with the diminishing ranks of operators, it won't be long before they are successful at narrowing our available frequencies. If it takes "tracking your RV" to bring in more Ham operators into the ranks, than so be it. I've been on VAF for quite awhile now and I can say there are some pretty dang smart people on here. Who knows when one of those smart people get their interest picqued by APRS and figure out a way to improve the APRS system or come up with something better. Isn't that what Ham radio is all about?

73's
KF4IVS
 
In looking at the last 1000 packets, it is clear to me that I got most of the red line errors when in central WA, which is the most populated area over which I flew. When further NW (Smithers BC to Williams Lake BC to Oroville, WA), there were virtually no red lines, and over central Oregon & northern NV, also few red lines. Perhaps someone can tell me what the lines mean (e.g., what causes the "rate limited" and "location changes too fast" errors)? And certainly some of the red lines seem to only report Wide 2-1 if I am reading things correctly.

Maybe changing the reporting time parameter to longer than 30 sec (I think that's what I currently am using and it is what I see between packets for straight-line flight last Monday) and/or disabling the smart beaconing would increase time between packets. The 22 seconds between packets was for today's flight (with some maneuvering flight, perhaps why there were more points reported).

Cheers,
greg
 
I plead guilty to Wide 1-1 as well. Much of my flying is done over sparsely populated areas and the only way to get coverage is Wide 1-1 (see my note in the "setup sticky" discussion. I would appreciate if someone with a bit more knowledge of all this would have a look at my recent tracks (N7965A - try either today or last Mon/Tues 18/19) and see whether there are "too many" packets going out and congesting the system. If this is the case, any suggestions for some sort of compromise where I might still have the utility of reaching secondary stations but not overloading the system?

thanks,
greg

Greg, I believe most of your rejected packets (red lines) are due to a couple of misconfigured digis and iGates. Notice most of the errors include KD7MQM and TOLGAT. Most likely these two stations are buffering packets, in other words, they hold them for awhile before relaying them to the aprs.fi server. This puts theses packets out of order with fresh packets and they get tossed out because the server thinks you have exceeded the 500km/hr speed limit.

For instance, look at this packet:

2011-07-18 23:55:18 UTC: N7965A>TW1RWW,TOLGAT*,WIDE1*,WIDE2-1,qAR,KB7DZR-10:`/0,(Si'/"M=}

Now this one which was rejected:

2011-07-18 23:56:20 UTC: N7965A>TW1RWW,KD7MQM*,TOLGAT*,WIDE2*,qAR,KB7DZR-10:`/0,(Si'/"M=} [Rate limited (< 5 sec)]

Notice the `/0,(Si'/"M=} code. This tells us this is two instances of the same packet. But look at the time stamps. KD7MQM (the villian :)) buffered the original packet 1:02 before sending it to the server. Now its position doesn't jive with the newest packet you transmitted:

2011-07-18 23:56:17 UTC: N7965A>TW1PWP,SCOOP*,WIDE2-1,qAR,N7OKG-1:`//w(ge'/"Lr}

The problem isn't with your tracker, it's with a ham operator who doesn't realize his station is buffering packets. There are simple fixes for the station operator but some hams aren't up to speed on this. It's a frustrating problem....wish some of the airborne APRS critics would try policing some of their digi station compadres..... ;)
 
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Sam, thanks for explaining the likely cause of strange tracks - eg buffered packets. I suffer from this alot here in the "mid-Atlantic region". Every local flight I've done within 100 miles has multiple strange zig-zags and "greater than 500kts" errors from packets out of order.
 
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Thanks Sam for the explanation - much appreciated since all this is a bit of a mystery to me (would have been useful to have some of this stuff on the amateur test!). Is there someplace that contains a list of the codes (or is it incredibly long/complex)?

My preliminary read of the code is that the codes after my tail number is the station sequence, followed by the Wide code, followed by the final reporting station that dumps stuff to the internet. Correct? And what is the qAR? Code preceding the final station?

Suggestions on any reconfiguration I should do? Going to 60 second intervals seems like a reasonable thing to me to relieve some of the congestion.

cheers,
greg
 
Yes, thanks Sam. I guess the million dollar question is why APRS doesn't have any kind of timestamp or sequencing code in their packet that will identify it and how relevent it is. Would this overload the airwaves more than duplicate packets? Could this be done at the digipeater or igate so other igates could poll the system to see if has received that info through another igate? Where is the bogdown, the airwaves or info into the server? somewhere accountability has to be thrown in there. Maybe something like the upcoming ADS-B system with a query and reply could give us an idea of how to expand the system and make it more effecient. Just thinking out loud. I obviously don't fully understand the constraints involved.
 
Been watching this thread with much interest, as quite a while back I installed the switch in my MT8000FA to enable a second profile. It appears to work quite well.

I use it as a hi/low altitude profile. Hi is set up for wide 2-1 only, for X-C and normal flight ops (especially maneuvering formation practice). Low is set up for wide 1-1 and wide 2-1, for search and rescue work, racing, and very sparse areas.

I went this route after a note from Allen on a day when he saw me beaconing the heck out of northern CA during a particularly turn-intensive formation workout (loads of smart beaconing). I felt quite bad about it, and made the changes ASAP. So I do hope our desire to be good neighbors continues to be recognized (and thanks on that front Allen!)

Other than the selectable wide 2-1 (by use of that switch), my profiles are pretty much from Sam's original settings sticky. Are there any modifications that you (Sam, Allen, Pete, etc) would recommend to that set-up profile, based on this discussion or in-the-field experience?

Please feel free to click on my track link in my signature and make recommendations if you feel adjustment is warranted. Thanks!

Cheers,
Bob

PS: Any chance that 108F days in New Jersey could have led to Vlad's mega-beaconing! :D (kiddin'!)
 
aprs.fi blog

A lot of info on how the aprs.fi server operates is in the archived blog of the author of aprs.fi:

http://blog.aprs.fi

Seems I recall a post on why timestamps aren't used in decoding packets. Lots of other good info as well and I recommend some time poking through the archives for anyone who wants a better understanding of this system.

You can also Google 'Bob Bruninga' , the father of aprs, and read his blog as well as other sites with background on how aprs works.

The settings in the sticky are still a good way to set up our trackers. Disabling SmartBeaconing will certainly cut down on the number of beacons while in maneuvering flight but the tradeoff of having accurate tracks in an emergency has to be considered. For most flights, SmarBeaconing only kicks in for a minute or so during pattern ops. The one thing that does make me cringe is seeing several hundred SmarBeaconing packets dropped during a formation practice flight. This would be considered abusive by about any standard.

There will always be 'aprs police' who don't appreciate the unique role of aprs in aviation and will grumble...we will never be able to satisfy some of them until we remove all trackers from aircraft...... ;)
 
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Allen,

For airplane use, could the RTG firmware switch based on speed rather than altitude as I noted above? That would work for any airplane anywhere and also work during cross country flights. Is there a way to key off of the GPS derived speed?

Glenn,

I believe you will find that "SmartBeaconing" will already accommodate a simple velocity vs transmission interval, without having to actually change configurations ( Meaning to switch the tracker to an entirely separate "page" of operating instructions) Ideally, Smart Beaconing ( Which is not our code) could be improved to consider altitude as one of its conditional operations.

On a related subject, as far as air mobile goes, I believe the problem is not so much an issue of the digipath ( in fact, at altitude, you could just eliminate a pathway altogether and still get into I-Gates) but of transmission intervals. When pilots fly aerobatics, they want enough position reports to get into the system as possible, and SmartBeaconing can do just that. The side effect of this is sending too many transmissions, and if you have not moved much, APRS.FI will just think you have sent a duplicate position report and ignore it anyway. Some digi's can also put you on the scroll of the living dead by putting you on their "enemies" list. (many hams will call me a blasphemer for stating that

The APRS network uses FM radio, and a phenomenon called "FM capture" lets the receiver in digipeaters "lock" onto the best transmission. Altitude provides an "unfair" advantage, since even with a very low power transmitter, you will have line of sight to the digipeater, and the 100 Watt Ground mobile tracker might be overwhelmed by our airborne units ( even those using 300 milliwatts, like our MT-300) The signal you send may not be good enough to actually be decoded by the digi, but it can "clip" the packet sent by another station, rendering both stations neutered. This is the paradox.

Since one I-gate can service airborne transmitters in open areas from hundreds of miles, it seems to me that if you want to send a lot of position reports quickly ( fast turn rates, etc) the best way would be to have an I-Gate on a separate frequency, and not jam up the airwaves with lots of position reports that just antagonize the APRS Police and effectively jam every digipeater out to the the horizon (+15 %-note: General Class test question!) You can make an I-gate with any receiver that can receive your intended frequency, and low cost or freeware from AGWPE.

Failing that, if you are planning to be in full time race mode, you need to choose a beacon rate ( either in SmartBeaconing or just the pre-programmed interval) that is not too fast. Our default rate for mobile trackers is every two minutes, but with our QRP transmitters (less than 10 Watts) a 70% throughput rate is pretty good. In the air, your throughout rate is going to be much higher than ground stations, so just don't go hog wild with your primary configuration transmission interval rate.

If there is a way to keep your secondary configuration available to send the "distress" signal, I think it would be optimal to program it thusly. Unlike an ELT, the APRS network keeps a retroactive account of your last positions, and this LKP report could significantly shorten the amount of time you are hanging upside down in a tree with Avgas running down your neck! As a backup system to your next gen or older ELT's, APRS is useful and cheap.

73,

Allen
VHS
 
Nothing below 650-750ft

Well, I configured my tracker to be a better citizen and when I'm above 1000ft AGL I my area, its working well. Sadly, my first packet is never before 650ft and often around 750ft. The same goes for my last packet. I guess this is not to bad but I'd like to find settings that cover the transition phases.

Thoughts? Recomendations?
 
I-Gate Opportunity

Well, I configured my tracker to be a better citizen and when I'm above 1000ft AGL I my area, its working well. Sadly, my first packet is never before 650ft and often around 750ft. The same goes for my last packet. I guess this is not to bad but I'd like to find settings that cover the transition phases.

Thoughts? Recomendations?


Sounds like it's time for you to be an even a better APRS citizen and set up an I-Gate to cover your first and last packets...that's what I did.
 
Sounds like it's time for you to be an even a better APRS citizen and set up an I-Gate to cover your first and last packets...that's what I did.

I've been shoppig around for the parts to set up a dedicated iGate. It looks like it will be around $500-$750 (2nd hand transceiver, used TNC, old laptop/computer, mast and antenna, cabling, etc. - did a test with a friend's transceiver and the 'sound card' TNC using my work laptop but had very poor luck balancing the audio quality). I will need to also insure I can manage bandwidth usage as my DSL is very anemic.

Any suggestions are welcome. (I've read Sam's post on the subject.)
 
Configuration change "on the fly"

Still high on the to-do list for this year is to build a new firmware that will allow you to select an alternate configuration automatically. In my ignorance, I assumed that this should be done as a function of altitude ( Living 6 feet above sea level gives me a myopic perspective), and for high altitude balloons, altitude profiling is important ( for that application, we are developing new hardware designs that will change power and configuration as a function of altitude and velocity) One of your members on this page suggested that the "aircraft" version should lean more towards configuration changes generally as a function of speed ( since we might expect generally, but not exclusively,see altitude above local ground as a function of velocity) This way we can go from a very narrow digipath setting at high altitude and velocity, and a wider path ( more like a car) when the aircraft is going less than X velocity.(Some number depending upon whether you are doing air races, terrorizing passengers with nap of the earth flying, or flying high in cross country flight. This of course can be handled now currently with a simple configuration switch, but we know that you have better things to do with your time in flight than worrying about your APRS settings. This is something we will probably see first in the Micro-Trak RTG FA, since new firmware can be re-written to the chip by you, and secondly, in an upgraded version of the basic TT3 chip used in the the single channel version of the RTG. ( This will require a chip upgrade) I will keep you advised.

Best regards,

Allen
VHS/Byonics
 
Thanks Allen. I've exchanged a few emails with Byon on this topic and have offered to do testing.

In looking at my local area (100 mile radius) we are void of an iGate so I feel I should also pursue setting on up since there are a number of APRS equipped aircraft transiting north-south along the east coast and I'd like to fill the void. If I can figure out how to do it "on the cheap" I'll try to package up the shopping list and instructions. Currently looking for low cost 2m receiver options with audio-out.
 
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