GPShöjdmätare

GPShöjdmätare translates to GPS altimeter or GPS height meter. It is a device or system that uses the Global Positioning System (GPS) to determine an object's altitude above a reference surface, typically mean sea level. Unlike barometric altimeters which measure atmospheric pressure, GPS height meters rely on the signals transmitted by GPS satellites.

The principle of operation involves calculating the distance from the GPS receiver to multiple satellites whose positions are known. By triangulating these distances, the receiver can determine its three-dimensional position, including its altitude. However, GPS altitude measurements are generally less accurate than horizontal position measurements. This is partly due to the geometry of the satellite constellation and the fact that GPS signals are more affected by atmospheric conditions at higher altitudes.

To improve accuracy, many GPShöjdmätare systems employ techniques like differential GPS (DGPS) or Real-Time Kinematic (RTK) positioning. These methods utilize ground-based reference stations to correct for errors in the satellite signals, significantly enhancing altitude precision. Applications for GPShöjdmätare include surveying, aviation, maritime navigation, geodetic research, and outdoor recreation. They are often integrated into handheld GPS devices, smartphones, and professional surveying equipment.