Know About GPS Technology #Part 1

GPS (Global Positioning System) is a system of satellite navigation and positioning that is owned and managed by the United States. The system is designed to provide position and velocity of three-dimensional as well as information regarding the time, it continuously throughout the world without relying time and weather, for many people simultaneously. Today GPS is widely used around the world in various fields of application that requires information about the position, velocity, acceleration time or throughput. GPS can provide position information with accuracy varying from a few millimeters (order zero) up to tens of meters.

GPS Capability

Some GPS capabilities, among others, can provide information about the position, velocity, and time is fast, accurate, inexpensive, anywhere on earth without depending on the weather. It is worth noting that GPS is the only navigation system or positioning systems in some of this century that has such powerful capabilities. The accuracy of GPS can reach a few mm for the accuracy of its position, a few cm / s for speed and accuracy of several nanoseconds for time accuracy. Position accuracy obtained will depend on several factors: the positioning method, the satellite geometry, the level of data accuracy, and data processing methods. 

Given product from GPS
In general, products from the GPS are position, velocity, and time. In addition there are several other products such as acceleration, azimuth, attitude parameters, TEC (Total Electron Content), WVC (Water Vapour Content), Polar motion parameters, as well as some products that need to be combined with external information from other systems, products include high ortometrik , undulasi geoid and vertical deflection.


The principle of positioning with GPS

The principle of positioning with GPS is using the method of resection of the distance, where distance measurements carried out simultaneously to multiple satellites of known coordinates. At the of GPS measurements, each epoknya has four parameters that must be determined: the three parameters of the coordinates X, Y, Z or L, B, h and one time due to parameter errors in the satellite ketidaksinkronan clock oscillator with a clock in of GPS receiver. Therefore, a minimum required distance measurements to four satellites.

Type of equipment (Receiver) of GPS

There are three types of GPS devices, with each providing a level of accuracy (position) which is different. The first type is the type of GPS Navigation (Handheld, Handy of GPS). Type nagivasi price is quite cheap, about 1-4 million dollars, but the accuracy of the current position given the new can reach 3 to 6 meters. The second type of tool is a single frequency geodetic type (type mapping), commonly used in survey and mapping that takes a position accuracy of about an inch up to several decimetre. Last type is the type of geodetic dual frequency which can provide position accuracy to achieve millimeter. This type is commonly used for precise positioning applications such as construction net of control points, deformation surveys, and geodinamika. Geodetic type receivers prices are quite expensive, reaching hundreds of millions of dollars for one unit.

Continue to #Part 2