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  2. Lidar - Wikipedia

    en.wikipedia.org/wiki/Lidar

    Within the category of airborne lidar, there is sometimes a distinction made between high-altitude and low-altitude applications, but the main difference is a reduction in both accuracy and point density of data acquired at higher altitudes. Airborne lidar can also be used to create bathymetric models in shallow water. [41]

  3. Terrain-following radar - Wikipedia

    en.wikipedia.org/wiki/Terrain-following_radar

    TSR-2 XR220 at RAF Museum Cosford, 2002. Ferranti developed the first terrain-following radar specifically for the TSR-2. Terrain-following radar (TFR) is a military aerospace technology that allows a very-low-flying aircraft to automatically maintain a relatively constant altitude above ground level and therefore make detection by enemy radar more difficult.

  4. Aerial survey - Wikipedia

    en.wikipedia.org/wiki/Aerial_survey

    Typical data collected includes aerial photography, Lidar, remote sensing (using various visible and invisible bands of the electromagnetic spectrum, such as infrared, gamma, or ultraviolet) and geophysical data (such as aeromagnetic surveys and gravity measurements). It can also refer to a chart or map made by analyzing a region from the air.

  5. Radar horizon - Wikipedia

    en.wikipedia.org/wiki/Radar_horizon

    With this calculation, the horizon for a radar at a 1-mile (1.6 km) altitude is 89-mile (143 km). The radar horizon with an antenna height of 75 feet (23 m) over the ocean is 10-mile (16 km). However, since the pressure and water vapor content of the atmosphere varies with height, the path used by the radar beam is refracted by the change in ...

  6. Atmospheric lidar - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_lidar

    Atmospheric lidar is a class of instruments that uses laser light to study atmospheric properties from the ground up to the top of the atmosphere. Such instruments have been used to study, among other, atmospheric gases, aerosols, clouds, and temperature.

  7. Radar altimeter - Wikipedia

    en.wikipedia.org/wiki/Radar_altimeter

    The dipole antenna of a radar altimeter of 1947. A radar altimeter (RA), also called a radio altimeter (RALT), electronic altimeter, reflection altimeter, or low-range radio altimeter (LRRA), measures altitude above the terrain presently beneath an aircraft or spacecraft by timing how long it takes a beam of radio waves to travel to ground, reflect, and return to the craft.

  8. Tethered Aerostat Radar System - Wikipedia

    en.wikipedia.org/wiki/Tethered_Aerostat_Radar_System

    The largest lifts a 1000 kg payload to an operating altitude providing low-level, downward-looking radar coverage. The aerostat consists of four major parts or assemblies: the hull and fin, windscreen and radar platform, airborne power generator, and rigging and tether; they are kite balloons obtaining aerodynamic lift from relative wind and ...

  9. Very low Earth orbit - Wikipedia

    en.wikipedia.org/wiki/Very_low_Earth_orbit

    The Japanese Space Agency, JAXA, launched its Super Low Altitude Test Satellite, or SLATS (“Tsubame”), in 2017, whose orbit slowly decreased from an initial altitude of 630 km (391 mi) to operate at seven different altitudes, from 271 km (168 mi) to a final altitude of 167.4 km (104.0 mi).