What Are the Methods of Surveying With a GPS?

Global Positioning Systems (GPS) measure your location on the earth using satellite signals to track your coordinates. To undertake a survey using GPS, you need at least one receiver, either roaming or static. When you are designing your survey, you should consider the purpose of your survey and how you are going to analyze your data. These factors determine the survey technique you should use. Remember to integrate a control experiment into your survey and to ask for advice or training from a qualified GPS user to ensure accuracy in your data collection.
  1. "Stop and Go" Technique

    • This technique requires a stationary reference receiver and a roving receiver. You walk between points of interest with the roving receiver, stopping at each reference point (the stop phase) to collect the data coordinates. However, uniquely, you continue to collect data as you walk from point to point, the go phase. The stationary receiver keeps track of the roving receiver's satellite point, allowing you to cross-check and improve the accuracy of your data collection. This survey technique is useful if you need to survey multiple points that are close together and the terrain is flat, with no signal obstacles.

    Kinematic Survey Technique

    • This is similar to the stop-and-go technique in that it requires both a stationary reference and a roving receiver. However, in this technique you do not stop to take coordinates of points of interest but remain in continual motion. As you move, you record the position of the receiver "on the fly." The more readings recorded per minute, the more accurate the data track becomes. Surveyors typically use this technique in moving objects, such as to determine the position of an aircraft or to undertake hydrographic or road centerline surveys, for example.

    Static Survey

    • This is the most traditional survey technique. Here your GPS receiver(s) remain in a fixed location, typically on a specially designed stand. If you are measuring a specific area, you need to position a series of static receivers across the terrain. Each receiver must be able to observe carrier phase measurements and be capable of logging data. You should program the receivers to take multiple measurements over a long period of time to ensure accuracy. If you are taking measurements across distances of more than 20 kilometers, then you should use dual frequency receivers, otherwise single frequency receivers are acceptable

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