View Full Version : Using old Garmin GPS data

2009-11-12, 06:33 PM
I've got about 2000 points that were collected with an old Garmin handheld unit as much as 10 years ago. They're basically just points locating road signage throughout the County. Up to this point, the data hasn't really been usable, the guy that collected them neglected to put down intersection information....so the Road department only has LAT/LONG to deal with. Not very useful.

I've been asked if there is a way to convert this data into a usable format...

Trouble is coming when I try to find out what datum/projection the older Garmin units use, and converting that to a northing/easting format that CAD can digest.

County spreads out over at least 3 State Plane zones...so converting using one zone throws the others off that aren't in that zone.

Any suggestions?

Throw it away and send the surveyors out to collect Trimble points? I'd hate to trash this data, it does seem like it should be usable.

2009-11-12, 09:41 PM
How many of those signs that where there ten years ago still there?
The default in my Garmin units log points in WGS84 with 10 yr old data I would say they might be in NAD27 that's what my old GPS units had back then. Corpscom (http://crunch.tec.army.mil/software/corpscon/corpscon.html)should translate the points for you.

2009-11-17, 07:42 PM
That's probably a better question than the ones I've been asking. Was able to figure it out with the assist of the GIS guru. He created a shape file for me and added northing/easting to the excel file. Inserting a bit of linework from projects tells me they should be in the right place....or at least close. 5 feet accuracy with those older Garmin handhelds I think.

Half way there....data is now accessible....just have to figure out what we're going to do with it now.

I'm thinking it's going back into a spreadsheet, a set of printed plans would be insane...this County is gigantic.