Gathering Ground Control Points (GCP's) using various Global Positioning System (GPS) Devices.

Introduction:

 

This activity includes how gather control points and the use various ways of doing it.  We used the Dual Frequency Survey Grade GPS, which is the gold standard to compare all GPS data too.  This machine is very expensive but very accurate.  Next we used the Bad Elf GNSS Surveyor GPS, this unit is much cheaper to purchase but is still about $600 and should produce information of about a sub-meter of accuracy.  We used he Ipad tablet with this device to pinpoint the marker.  Finally we used the Bad Elf GPS, it is again another significant step down and it's accuracy probably relates to price as well.  There are other devices we could have used such as the Trimble Nomad GPS, the Garmin GPS or even your smart phone.  Each of these last mentioned devices are not nearly as accurate as the others.