A full-sphere encoder usually has two parameters, azimuth (or horizon) and elevation angle. Using three orthogonal magnetometers, both azimuth and dip (inclination) can be measured. Formulas for calculating geodetic azimuth are linked in the distance article. Separate receivers and antennas were used for azimuth and elevation detection. If the radius is zero, both azimuth and inclination are arbitrary. ERP will vary with azimuth (compass direction). Unit automatically acquires and tracks designated targets in azimuth elevation and range rate. "A" is the launch azimuth angle. It could measure altitude, azimuth and range. Wind direction is usually reported in cardinal directions or in azimuth degrees. Range, azimuth, and elevation were shown on a cathode-ray tube display. Scanning is carried out electronically in both azimuth and elevation. The HPIR automatically acquires and tracks designated targets in azimuth, elevation and range. It is determined by the latitude of the launch site and the launch azimuth (direction). Propulsion is provided by three Azipods, ABB's brand of electric azimuth thrusters.