[Madeschipper]

Dear all,

I'm looking for a new GPS unit with some specific requirements. I have been searching the net for a while, but haven't found what we are lookin for.
I hope one of the readers here can help me out!

I'm working at Delft University of Technology and tracking coastal surface currents fr research purposes.

We do that with 10 to 20 simple GPS buoys, that log their position every 2 seconds for a period of 3 hours.
w w.scienceofthesurf.com/assets/img_rip/RipCurrentExperiment.jpg

With postprocessing of raw GPS data we can bring down the accuracy to an acceptable level for our research.
Uptill know we have been using Delorme Blueloggers, one of the few low cost GPS units that have the capability of logging the raw GPS data combined with an external antenna.

An example of the output of the bouys in Google Earth can be found here
w w.surf.citg.tudelft.nl/REDNEX2011/movie_teaser.html


However working with the blueloggers is a pain form time to time.
1. It suffers from severe clock jumps which makes it difficult to postprocess the data.
2. It stores the data on volatile memory, which is erased if the battery is out for too long
3. Connection with bluetooth is slow and difficult (especially if your desk is full with 20 units)

Therefore we are looking for a replacement, that is more stable and can be connected to with a cable or has an Sd card.

Preferably the units have a GSMtracking option, so we can locate the units that are out of sight and pick the up with a boat.

I know that this list is quite demanding, but does anyone of you knows a product that can do this (or comes close)?


Thanks a million in advance!!!


Matthieu de Schipper

[typer]

Hi,

I have never seen a commercial product as you describe. The closest proof-of-concept is the prototype BeagleBoard + Ublox LEA4-T made by the team behind RTKLIB. They ported RTKLIB to work on the beagleboard and could log raw gps output to an sd-card as well as receive NTRIP data over a GSM-modem.

Maybe you could take a look at their project and do your own adaptations? See rtklib.com/rtklib_beagleboard.htm

Otherwise I would look into connecting a gps with serial port output with an arduino with an SD-card slot. Then it should be possible to log serial port data directly to the SD-card.