Research On Measuring The Attitude/velocity Of The Spacecratf Based On COMPASS

In the last century, the birth of global satellite navigation system lead a revolution to thefield of satellite radio navigation, applying the satellite signal receiver with the function ofpositioning equipped to the vehicles, ships and aircraft, which have been widely used. As theuse of global satellite navigation technology applications is expanding, the potential measuredattitude/velocity function is much favored by the majority of scholars. the subject ofmeasuring the attitude and velocity of the spacecraft using the COMPASS is based on China’sself-developed Compass navigation system, and do a research about measuring the attitudeand velocity for the spacecraft. Aims to develop a simple, low cost, small size, stability, goodhigh-precision attitude and velocity determination navigation equipment.The spacecraft attitude and velocity measuring system configures three of four (at leastthree non-collinear antennas) satellite signal receiving antennas on the surface of thespacecraft using a reasonable antenna configuration technology, then using the pseudo-rangemeasurements, carrier phase measurements, Doppler shift measurements, apply thedifferential technology and attitude measurement and speed measurement algorithm to get theattitude and speed information of the spacecraft.This paper firstly introduces the composition, the development, the current situation ofthe compass satellite navigation system and shows the survey of attitude and speedmeasurement using global satellite navigation system. Then it gives the pseudo-rangepositioning theory, the carrier phase linearization observation model, the single-differencemodel, the double-difference model and the three difference model. We also give a researchon the theory of attitude, antenna configuration and velocity measurement. Finally, we builtthe Matlab simulation platform for the spacecraft attitude and speed measuring system, wealso analysis the experimental data, and the simulation proves the validity of the method.Research on the method of attitude determination, the solution of the carrier phase integerambiguity has been a problem, this paper presents a geometric algorithm using the inherentcharacteristics of the multi-antenna attitude determination system to solve the carrier phasedouble-difference integer ambiguity, firstly we make a rough solution to the attitude angleparameters using pseudorange measurements after the carrier phase measurements beingsmoothed, then based on the crude attitude angle parameters, baseline vector parametersbetween the antennas and the satellite to the receiver baseline vector at the local levelcoordinate system, we build a geometric model to get the double-difference carrier phase integer ambiguity, finally we inversely compute the accurate baseline vectors between theantennas with the carrier phase integer ambiguity, then we get the precise attitude angleparameters with baseline vectors between the antennas. In the respect of speed measurement,we do a detailed study to three speed measuring methods, and propose a center valuedifferential compensation velocimetry based on the carrier phase value, we build a differentialspeed system with a base station, then use the carrier phase central value of the base station tocompensate the carrier phase central value of the carrier so that we can get a high-precisionspeed information.