Selecting the right GPS receiver for your job
Selecting GPS capabilities you will purchase and use will be based on computer processing capabilities of the unit. This is combined with the antenna it will use. All GPS units access data from the same satellites in orbit around the earth. The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radio navigation system. It is owned by the United States government and operated by the United States Air Force. The signals are provided to all users, free of charge. They use a radio based system to communicate from satellites to GPS units.
This is where user-collection-techniques raise to the highest levels of importance. A staff with a top mounted antenna, wired to the GPS device delivers the highest position location quality. The staff keeps the unit fixed and stable for a period of time to record a point averaging position. This technique increases the accuracy of the position recorded. The antenna mounted above the operators head-level also reduces multi-path propogation – allowing unobstructed view from antenna to satellite.
Other techniques to limit multi-path interference involves off-setting position recording from poor reception locations to clear-view points. These are the techniques each operator should learn, experiment with, and use on every GPS data collection project.