Monday, November 12, 2012

GPS Tracking

Misc information about GPS tracking devices and solutions.

What I'm looking for is a solution to track ultra runners during races lasting up to 30 hours or more.
Requirements on tracking device (the thing the runner will carry along, this could as well be a smartphone app):
  • Very Long Battery Life >30h (while almost continuously send GPS data)
  • Optional: replaceable batteries or at least ability to charge device while on the run. Or external battery connector ...
  • Send position data via GPRS connection to any computer on the internet
  • Configurable time interval for sending data (continuously vs. 10-20min. intervals)
  • Sleep mode (power-off GPS/GSM while not sending data)
  • Optional: Multiple Geo-fences (e.g. Alert when running through aid station)
  • ...
In addition a web portal is required to visualize the runners along a given course.

Currently I think only two types of hardware tracker would make sense:
  • GPS (or in the future other satellite system) / GSM tracker:
    • gets location via satellite and transmit position data via mobile phone network (GPRS)
    • advantage is relative low cost for data transmission
    • disadvantage are roaming costs if used across different countries, mobile network coverage sometimes not available.
  • GPS / Satellite communication tracker"
    • this is what e.g. SPOT tracker do. You receive GPS position and transmit via satellite communication network  
    • disadvantage relative high cost almost always you need to subscribe for monthly or yearly provider plan and pay in advance.
    • advantage is depending on area and satellite communication provider usually good coverage.

This page is work in progress!!

List of Tracking Devices:

Tracking Portal:

GPS CatTrack Live 3

Information about CatTrack Live 3 Tracker can be found here.

Battery Testing

In the chart below I thought I had configured an 10 minute time interval for sending data via GPRS, however the server receives this only about every 20 minutes ?!?
The device was running already for almost a day before I started recording the data (battery at about 75%) but I missed the data.
It looks similar to a typical discharge curve of Lithium Ion Cell.

Second chart, configured CatTrack Live device to send data in 5 minutes intervals which resulted in tcp connections to the server roughly every 10 minutes (??!)
First data shot was received at 11/13/07:28:18 (battery at 100%) and the last one at 11/15/10:10:23 (with battery indication of 10%).
This means a good 50 hours operating time with GPS positions transmitted in an interval good enough for ultra trail races (like a 100 miler or so).

Here the GPS data is shown:

JUNUT 2013

Jurasteig Nonstop Ultratrail