Höjdmätare

Höjdmätare, often translated as altimeter, is an instrument used for measuring altitude. There are several types of höjdmätare, each employing different principles for determining height. The most common types include barometric and GPS-based höjdmätare.

A barometric höjdmätare works by measuring atmospheric pressure. As altitude increases, air pressure decreases. The instrument is calibrated to correlate specific pressure readings with corresponding altitudes. These devices are useful for general altitude indication but can be affected by changes in weather conditions, which also alter air pressure.

GPS (Global Positioning System) höjdmätare utilize signals from satellites to calculate a receiver's position in three dimensions, including altitude. This method generally provides greater accuracy than barometric types, especially in open areas with clear satellite reception. However, GPS signals can be obstructed by buildings or dense foliage.

Other types of höjdmätare include laser and radar altimeters, which are typically used in aviation and surveying for precise distance measurements to the ground or other objects. Laser altimeters emit laser pulses and measure the time it takes for them to return after reflecting off a surface, while radar altimeters use radio waves for similar measurements. These instruments are crucial for navigation and safety in various applications.