June 20, 2007

Some Common GPS myths

Spent the lunch hour here listening to a gentleman from Trimble discuss GPS, GPS myths etc... Some Common GPS myths:
WAAS will work everywhere
GPS will work everywhere
All GPS receivers are the same
You can use a rec. GPS for GIS data collection
US coast guard beacons are coastal
Selective Availability is still on or will be on again
You can get an accurate position with less than 4 satellites
Other people can track you if your GPS is on
All basedata is accurate
Aerial or satellite imagery will replace the need for GPS
Datums are not important when collecting GPS
WGS84 datum is the same as NAD83
Vert accuracy is the same as horizontal accuracy
See also http://www.trimble.com/gps/index.shtml

2 comments:

Chris C. said...

This reminds me of the time I received GPS data from a client for a bunch of monitoring locations, which were meant to fall within a fairly large site. I couldn't figure out why none of the points were falling inside the site.

We eventually held a conference call where we discussed what could be the problem. We finally got round to asking the client what kind of GPS receiver was used, after a few ums and aws he finally squeaked out that his all powerful cell phone had been used. Well at least the points were in the right city! :)

paulw said...

>Other people can track you if your GPS is on

well, there is a point here.. if i leave my GPS on as i go somewhere.. and that GPS falls into someone elses's possession, they can find out where i've been.. that is other people tracking me because i had my GPS on (albeit time shifted)..

Hey, I'd like to know more about vertical accuracy, any tips?