SSA Sailplane Tracker

On Thu, 24 Sep 2020 09:49:32 -0700, Steve Koerner wrote:

There is also one more mode of tracking that can also work at high
bandwidth - phone tracking. Like other ground based systems it suffers
dropouts (more so than ADS-b in my experience with it). The beauty of
the phone tracking app is that it doesn't require expensive avionics.
The phone tracking system seems to have lost favor. I'm not sure if
it's still supported.

Phones don't necessarily provide good coverage everywhe I've sat over
the middle of Huntingdon, a market town 15 miles NW of Cambradge, at
3000-3200 ft and had exactly zero phone signal: The British telcos keep
coverage as near-pancake-shaped as possible because that reduces the
transmitter power bills and anyway they don't seem to think anybody needs
to use a phone above 500ft or so.

I expect its the same in Holland, Belgium and much of France.

Is this also the case in the flatter parts of the USA?


--
Martin | martin at
Gregorie | gregorie dot org

On Thursday, September 24, 2020 at 3:17:58 PM UTC-4, Martin Gregorie wrote:
On Thu, 24 Sep 2020 09:49:32 -0700, Steve Koerner wrote:

There is also one more mode of tracking that can also work at high
bandwidth - phone tracking. Like other ground based systems it suffers
dropouts (more so than ADS-b in my experience with it). The beauty of
the phone tracking app is that it doesn't require expensive avionics.
The phone tracking system seems to have lost favor. I'm not sure if
it's still supported.

Phones don't necessarily provide good coverage everywhe I've sat over
the middle of Huntingdon, a market town 15 miles NW of Cambradge, at
3000-3200 ft and had exactly zero phone signal: The British telcos keep
coverage as near-pancake-shaped as possible because that reduces the
transmitter power bills and anyway they don't seem to think anybody needs
to use a phone above 500ft or so.

I expect its the same in Holland, Belgium and much of France.

Is this also the case in the flatter parts of the USA?


--
Martin | martin at
Gregorie | gregorie dot org

My recent experience is that yes the phone app (IGCdroid) still works, and reasonably well. If you look later at the flight log as received by Glideport.aero you will usually see the whole flight in detail, same as looking at the IGC file collected within the phone.

What is invisible (unless you watch the flight in real time on Glideport) is that the cell reception drops in and out. The acummulated data is sent once reception is restored. To see the dropouts I have used a macro text editor on the IGC files to leave only the last B record before each "LPLT::SND" line which denotes the app sending a data packet. The resulting IGC-like file can be looked at in software such as SeeYou and then you can see which areas did not have cell coverage in the air. I find that they are approximately repeated if you fly the same route again. And they differ when you fly in opposite directions along the same route (may be related to pilot's body blocking the signal in a certain direction).

Generally the dropouts are on the order of 10-15 minutes, but sometimes longer, up to an hour, in our area (VT-NH, wooded, hilly, somewhat populated relative to Nevada, with the population often complaining about spotty cell coverage). It's possible I'd get better coverage if I'd put the cellphone in a better location in the cockpit, I've had it several inches behind my back. (No carbon fiber in my glider.)

It's a lot of fun for spectating, and costs almost nothing, only requires a phone with data plan, not FLARM nor a transponder nor satellite-based devices (other than the phone's GPS reception). But for search and rescue the utility would be limited, since the last data packet may be sent many minutes, even an hour, before the crash or landout, as cell service is fairly likely to be lost once on the ground. I also carry a PLB, but would need to be able to activate it after the crash. Thus an OGN network, logging FLARM signals, if it were set up in our area (there is none so far), would be a useful complement.

How to find an iPhone app similar to the app for Android phones, to work with Gliderport.aero?