Equipment Research

GPS surveying vs. Total Station surveying

Used in  designing restoration and conservation projects in the Octoraro watershed

GPS

• Gives a position within seconds
• Necessary to have clear open sky without physical barriers for signal to connect with satellites 
• Do not need to reference to any other location to record position
• Can be used anytime of the day, even at night
• Only requires one individual to operate and simple to record observations
• Control points are able to be placed offsite so it will not be disturbed by site activities
• Calibration can be done by the operator at any moment
• An expensive tool at first, though lower cost in maintenance 
• Easier setup with only having to turn on the instrument and it is guided to the position on the screen
• Has no moving parts such as leveling devices that can be knocked out of adjustment

Total Station 

• Must be oriented to a known point of reference before continuing to observe another reference object
• Necessary for a line of sight from the station to the reference object
• New points must refer back to a known hub
• Requires sufficient lighting for laser from total station to prism held at a reference object
• Using this device effectively requires two people and surveying experience/training
• Control points must be closer for recording, but can be disturbed by site activities
• The instrument requires calibration, and updates periodically
• More affordable in beginning though maintenance is costly
• There is a process to setting up the device where error can easily occur at any point
• Is more sensitive and can easily be knocked out of adjustment

The GPS surveying equipment seems to be the most efficient and effective surveying method if out in the open. Though, if it is under tree canopy or any other obstruction, the older method of surveying using a Total Station would be the better option.