A Study Of Arithmetic For Automatic Antenna Track Of Satellite

Inmarsat uses twelve synchronized satellites to provide service for millions of users in the earth and sea. The main four satellites distribute on the synchronized track 36000 kilometer above the equator in Pacific, Indian and Atlantic Ocean, overcastting Pacific, Indian, east Atlantic and west Atlantic Ocean. No matter where you are in the world you can communicate with others using Inmarsat satellites.While navigating in any ocean in the world, in order to establish the communication between ships and satellites, earth station and satellites, the ships have to make sure that antennas should always aim at the Inmarsat satellites to ensure the signal of antennas pointing to satellites, so people have to open up relevant automatic tracking methods. According to the tracking principles, there are following automatic tracking measures: Step tracking, taper scanning tracking, single pulse tracking, program tracking, memory tracking and track forecast tracking, and so on.The paper firstly introduces the mathematical basis of the land receiving antenna's orientation relative to Inmarsat satellite, educes mathematical formulas of antenna's orientation in geography coordinate and carrier coordinate and emulates the arithmetic of models in Pacific and Indian Oceans according to this mathematical model; Then the thesis advances the track principle of Inmarsat communication system in this project, which is the method of combining program tracking and comparing the largest energy signal, to realize the purpose of tracking Inmarsat satellite accurately. Subsequently, it introduces the function and characteristic of inclinometer and gyro sensors used for tracking in this project and design the arithmetic concerning to angle based on the two sensors, mainly the integral arithmetic of gyro sensor. Then the paper analyzes the arithmetic principle of tracking steadily in the process of antenna track and the compensate arithmetic's realization in the state of searching and tracking, basing on the mathematical model of antenna pointing and the algorithm of sensors. In the end, the thesis puts forward two methods of optimizing as well as each advantage and application methods, then discusses the realization of checking list method to optimize the performance of software detailedly. After the efficiency analyzing of the optimizing, the paper presents the harvest of the optimizing: advancing the arithmetic efficiency of the azimuth of satellite by 200 percent.