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[WA7ARK]

What path should be used from an aircraft flying ~10kft msl in the western US?

At what altitude is it ok to use WIDE2-1?

Do any trackers switch PATH automatically based on GPS-derived altitude?
If not, has anybody written Arduino code to parse altitude out of GPS sentences?

[WD9EWK]

What path should be used from an aircraft flying ~10kft msl in the western US?

At what altitude is it ok to use WIDE2-1?

If you're up at that altitude, you're probably fine to go with WIDE2-1, and definitely good to drop WIDE1-1 from the path.

Do any trackers switch PATH automatically based on GPS-derived altitude? If not, has anybody written Arduino code to parse altitude out of GPS sentences?

The PicoAPRS automatically switches to WIDE2-1 when it is above 3000 meters (about 9248 feet) altitude.

http://picoaprs.de

73!

[WA7ARK]

So is this your recommendation?

High altitude: WIDE2-1

Low altitude: WIDE1-1, WIDE2-1

The reason I ask is I presently use only WIDE2-1, and get yelled at for causing congestion when above about 9000ft msl. It depends a bit on where I fly, but most of my flights are in AZ, UT, NV, ID, MT and VE6

[WB6TIX]

The high altitude balloon folks that use aprs to track the balloons probably have some really good info on all of this.

I'd probably go with...low altitude WIDE2-1 and high altitude "no path at all".

Eric

[WA7ARK]

The high altitude balloon folks that use aprs to track the balloons probably have some really good info on all of this.

Here in AZ, the balloonists do not send packets on 144.39MHz; they use an alternate frequency.

[WD9EWK]

So is this your recommendation?

High altitude: WIDE2-1

Low altitude: WIDE1-1, WIDE2-1

The reason I ask is I presently use only WIDE2-1, and get yelled at for causing congestion when above about 9000ft msl. It depends a bit on where I fly, but most of my flights are in AZ, UT, NV, ID, MT and VE6

For low-altitude or ground-based APRS, I go with WIDE1-1,WIDE2-2 as my path. Better chance to get packets to a gateway. WIDE2-1 seems reasonable for high-altitude work.

73!

[WA7ARK]

Check WA7ARK-9 for this morning's flight. APRS.fi reports this a "seriously bad path" for most of the flight. Only when we descended to below ~7500msl just north of I40 did .fi begin characterizing it as a "good path"

I also have the option of reducing transmitted power from 5W to 1W without adding an attenuator....

[WA7ARK]

I'd probably go with...low altitude WIDE2-1 and high altitude "no path at all".

With a null PATH, does that mean that my packets have to hit an IGate on the first hop, with no digipeaters involved?

[WA7ARK]

The best on-line guidance I found since my post is here:

http://www.nwaprs.info/mobilesettings.htm

That page ends with: If it flies: WIDE2-1, once every minute or two minutes. ...which is what I have been doing.

[WB6TIX]

With no path, the digipeaters will ignore you, so yes, an I-gate must hear you in order for your reports to get into the internet...so the question becomes, "Are there I-gates in range when you're flying?"


One thing I just found is Kenneth Finnegan's Master's Thesis on the subject of APRS. It's an interesting read at
https://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=2449&context=theses

On the 61st "sheet" of the thesis (labeled as page 54 in the printing) he talks about path settings for various stations.

He also goes on to mention that discussions of generic path recommendations get muddied with discussions of the unusual cases where it would make sense to use something other than the generic recommendations.  Since you're both up in the air and on the ground...unless your tacker can change paths based on altitude, your use probably counts as an unusual case.  So, I wouldn't be "ashamed" of a WIDE2-1 path report going out every couple of minutes. :-)

[WA9AFM]

What ever you do, don't use "Relay"!!!!

Had a balloon launch in central Oklahoma that used "Relay".  Tied up the APRS circuits for hours.