10hz GPS for data collecting for openstreetmap

**Chester** · 06-15-2010, 09:24 AM

Howdy all,

I'm looking at picking up another GPS unit to use for gps tracking in order to give something back to the Open Street Map system.

But I was thinking that a 5hz, or even a 10hz GPS would be better for data logging, as a lot of my driving would be at 60km/h or faster.

There are a couple of options, either this one:

http://www.semsons.com/wigiwblgpsre.html

Which comes in at US$60, or getting one of these:

http://www.littlebirdelectronics.com...t-Antenna.html

For AUD$67, although that would require soldering a USB serial adapter onto it, and possibly playing round with software and drivers to get it to run properly.

The main question is, would a 10hz unit give better datalogging? I am assuming it would be able to handle twists and bends in the road slightly smoother than a 1hz or 5hz unit.....

Your thoughts people? I'm happy to spend that kind of money, and I can then update the unit in the car to this one once I have the datalogging figured (I currently just use an iGPS-m Pro 1hz USB GPS, so the update to something faster would be good for me with GMPC). I could even integrate the datalogger into the carpc, although for now I would just sit the laptop on the passenger seat while I'm out for a drive, and leave the carpc for my regular music/nav duties.

**tripzero** · 06-15-2010, 11:16 AM

I'd go with a 5Hz unit. If you do the math, 60 km/h == 60000m/h or 16.66m/s. At 5Hz,you'll be getting a fix every 3.33 meters which is pretty good. At 10Hz, it's every 1.66 meters. My assumption is roads don't change significantly under 3 meters (otherwise, your car would probably skid off the road).

**Chester** · 06-15-2010, 07:03 PM

hmmm, good point, although for the price of the first unit (The WBT-300), I could get that, then just run it at 5hz.

Might snap one up I think, and have a play around

**Sicarius** · 06-16-2010, 10:33 AM

I actually have the Wintec unit on my car-PC. It's a nice unit but not without its issues.

The only real problem I have is that it will sometimes refuse to get a lock when coming out of hibernation. It will just sit there, no satellites seen, for a long time (20 minutes or more? I usually don't have that much patience). A power cycle usually brings it right back. It seems to happen much less often since I got the latest drivers, though, perhaps 1-2 times a month.

10Hz works but you may want to disable differential GPS as it can drop updates due to the extra computation involved. Either that or drop down to something like 5-8Hz.