How Does A GPS Surveying Equipment Function?

The GPS surveying equipment has been used worldwide to determine the various land positions accurately. GPS stands for Global Positioning System.

A GPS surveying equipment comprises mainly four components: GPS receiver, GPS antenna, GPS antenna cable, and the power supply. The GPS receiver is used to measure log data to the computer's hard disk. Generally the GPS receivers are light in weight, portable, and if used properly they can measure the baseline lengths to a great degree of precision. The GPS antenna is used to track various GPS satellites. The GPS antenna cable is used to connect the GPS antenna and GPS receiver.

Working of a Static GPS Surveying

Static GPS surveying involves the use of two receivers for measuring the three-dimensional vector between two points. This is called the baseline. GPS baselines are supposed to measure up to an accuracy of 4 mm and 7 mm in the horizontal and vertical directions, respectively. However, in practice, this is hard to take place.

The phase center of GPS antenna accepts the GPS signals. Hence, the baseline measures the vector (distance in a particular direction) amid two antenna phase centers. This vector is needed to be reduced to two points on the ground. For this, the height of antenna phase centers above every point has to be measured with utmost accuracy. Also, the antennae are required to be precisely set up above every point.

The GPS receivers log the GPS data on the hard disk. In the static GPS, two receivers simultaneously log the data from a common satellite and for a specific period of time. Longer this time slot is, better the GPS data is collected. The data accepted from each receiver is combined during the stage of post-processing. It is important to note that the receivers of the GPS surveying equipment do not interact with each other in any manner. Also, the GPS receivers must not be intervisible.

You should know about some precautions regarding GPS surveying equipment before conducting the GPS survey. During the initial stage of GPS equipment set-up, it is very important to record some useful information. Some part of the information is required to start up the receiver during the initial stage and some part of information is required for various post-processing needs. Some points to be taken care of before the set-up of GPS surveying equipment are:

The data collected while surveying may be temporary in nature. Hence, it is important to store it effectively as its recollection is almost impossible. If the recollection of data is necessarily required then the financial cost for doing so may be very high.

GPS surveying equipments are in use for various scientific explorations to obtain clear and accurate information on various land positions.