3 results about "Geosynchronous orbit" patented technology

The present invention relates to a shipborne satellite communication system and a method for a shipborne antenna to track a satellite. The shipborne satellite communication system comprises an antenna base, a satellite communication antenna, an MEMS inertial measurement unit and a servo driving unit; the satellite communication antenna is arranged at the antenna base and is used for receiving and transmitting the Ku or L-band communication signals of a geostationary orbit communication satellite or a small-angle geostationary orbit communication satellite; and the MEMS inertial measurement unit is arranged on the antenna base and is used for acquiring the attitude parameters of a hull; and the servo driving unit is arranged on the antenna base and is used for driving the satellite communication antenna to rotate so as to adjust the azimuth angle, pitch angle and polarization angle of the satellite communication antenna. With the shipborne satellite communication system and the method for the shipborne antenna to track the satellite of adopted, the satellite communication antenna can accurately track the satellites in a surge state, the installation complexity of the MEMS inertial measurement unit is decreased. The overall structure of the shipborne satellite communication system is compact, and the size of the shipborne satellite communication system is small.

The invention discloses a calibration optical system based on a geosynchronous orbit differential absorption spectrometer. The calibration optical system is composed of an oscillating mirror system, afront optical system, a solar diffuse reflection plate assembly and a solar light blocking door assembly. The oscillating mirror system is composed of a pointing mirror, a sweeping shaft system, a motor harmonic group and an oscillating mirror U-shaped bracket. The front optical system consists of a primary mirror, a secondary mirror, a third mirror, a plane mirror and a slit. The solar diffuse reflection plate assembly consists of a Teflon diffuse reflection plate and corresponding structural components. The solar light blocking door assembly includes a solar baffle and a motor assembly. Thecalibration optical system introduces a bidirectional reflection distribution function of external solar illuminance with known spectral irradiance at suitable on-board calibration time, thereby accurately measuring the diffuse reflection plate and establishing an approximate lambertian surface source with known spectral radiance to provide known radiation input for a remote sensor. The system has high measurement accuracy, compact volume, light weight and high reliability.

The invention discloses a method for measuring loss of a large-scale double-reflector antenna. The method comprises the following steps: firstly, measuring the power gain of the large-scale double-reflector antenna by using a radio power source method; then measuring antenna orientation and pitching power directional diagrams in a limited angular domain by using a beacon of a geosynchronous orbit stationary satellite, and calculating directional gain of the antenna by using a numerical integration method; and finally, calculating the loss of the large-scale double-reflector antenna according to the measured antenna power gain and directional gain and considering antenna irradiation loss correction, support shielding correction, axial cross polarization loss correction and mismatch correction. The method is simple and feasible, and has popularization and application values.