[aprssig] Appalachian Trail Tracking

[Andrew P.]

Looks like it's time to add polygon filtering. Just draw a polygon around the line you specify or make a polygon enclosing a selected line and bingo! Filter only on position reports inside the polygon. Distance to line would work too, but might be more computationally intensive.

I'll see about adding that feature to YAAC.

On the other hand, couldn't the Appalachian Trail just use an AltNet? Easy to filter on that.

Andrew Pavlin, KA2DDO

Sent from my Verizon Wireless BlackBerry

-----Original Message-----
From: "Lynn W. Deffenbaugh (Mr)" <ldeffenb at homeside.to>
Date: Mon, 27 Feb 2012 21:27:53 
To: <aprssig at tapr.org>
Subject: Re: [aprssig] Appalachian Trail Tracking

On 2/27/2012 4:13 PM, Bob Bruninga wrote:
> Can you or Hessu think of a way to aggregate all this data into one 2000
> mile long string of data?  Or do we just collect callsign reports and then
> wait till we have enough data and then manually connect them?

I've been playing around with OpenStreetMap data recently and they seem 
to have the Appalachian Trail in as a way of connected nodes.  It'd be 
really neat if there was an easy way to detect an APRS position report 
close to this line to get an automated way of collecting points, but I'm 
not that good with geo-relations in PostGreSQL (yet).  So for now, the 
only thing I would know is to manually collect and connect reports as 
submitted by the hikers using callsign and date/time range.

> Even if we came up with a clever SYMBOL or other flag to indicate the AT,
> the chances are that some will forget it and do it wrong, so we will end up
> having to manually connect the data anyway.

Yeah, that's probably not even worth asking them to do, IMHO.  We'll get 
more people telling us when they were there than we would people getting 
the symbol right.

> So unless you have a clever idea, Im just going to ask everyone to REPORT
> their DATES and TIMES and CALLSIGN when they were actually on the trail and
> we can aggregate it later?

That's a good start.  If we have that information, we can always do it 
the hard way.  If we miss capturing that data, we might miss our last 
chance to get what you're after.


> How long is data retention in your data base of Hessu's before we have to be
> sure to capture the data?

My DB is limited to 5 days (sufficient for my purposes), but I store all 
raw packets forever (for now), so I could go back and resurrect paths if 
necessary.  But I believe Hessu keeps posits in his DB for a LOT longer 
than my 5 days and has some good queriability to boot.

> We will ask all hikers to use a 2 minute rate while hiking unless they are
> running Proportional Pathing, then a 1 minute rate is the same thing.

Did AL0I-7 do one of your "destination" posits earlier today?  If not, 
then he's backtracking for some reason today.  Hopefullly the following 
screen cap will come through.  His first posit was to the SW, then he 
jumped to the NE and is now working his way back.  Last posit was 1.75 
hours ago.



Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32