Recommended Tracklog Interval for Haiti/Caribbean?

[KristaWhite]

I'll be going to Haiti in May to do some GIS work and will be using the Tracklog.  I want to record the first leg of our trip - from Port-au-Prince to rural Mizak (in the mountains of the Southeast Department near Jacmel).  This is a 4 hour car trip, and I don't want to bog down my Trimble GeoXH too badly with data if I don't have to.  I'm hoping to upgrade to ArcPad 10 before leaving, but currently have ArcPad 8 on the Trimble.

Does anyone have any idea what I should set the frequency of my tracklog interval to?  Should it be different than it is in the U.S.?  I haven't done any fieldwork in Haiti yet, so I'm not sure how many satellites I'll be able to receive and how frequent the readings might be when I'm there.

Any guidance would be greatly appreciated!

[AlexMahrou]

It's unfortunate that the GPS tracklog in ArcPad only allows for recording by time.  A distance filter would make it easier for your purposes.  Is the GPS antenna going to have a view of of the sky (at least partial?), or is it going to be inside a backpack 😞 ?  For a four hour trip, to get the best data, I would set up a feature class ahead of time for this purpose and turn off the tracklog.  My reasoning is because you can log by distance when collecting a polyline feature in ArcPad using the "distance interval" under your GPS Preferences.  I would set this to 5-10 meters.  That way if the bus is stopped (which I'm sure it will occasionally), you won't be logging data and end up with a vertex editing nightmare on the backend in ArcMap. 

Also, will you have GPSCorrect loaded on the unit or will you just be using the NMEA sentences for GPS?

[KristaWhite]

Admahrou, thank you for your reply.

We didn't end up going, but I hope to return in January some time and use this.

I planned on taking an external antenna with me and sticking it out the window.  We may not stop too often, but I think your suggestion for using "distance interval" is a good one.  I could even go as high as 20 meters on the interval and get the data I need (assuming the interval goes that high).

Yes, I have GPSCorrect loaded, and now have ArcPad 10 so it's a whole new world.

Thanks again for your suggestion!