Research On The Method Of Acceleration Determination Based On GPS

There are three methods for the determination of the acceleration based on differential GPS carrier-phase technology: position differentiating, velocity differentiating and direct carrier method. Position differentiating method is based on the precise relative positioning result, which is twice time differentiated to derive the acceleration; velocity differentiating is the method to differentiate the velocity result, which got by using the first carrier-phase derivative as measurement and based on the direct velocity determination method; and the direct carrier method uses the second carrier-phase derivative as measurement, which is based on the relationship between the measurement and the acceleration.Referring to the determination of the acceleration, this paper mainly researched problems of two aspects:First, researching the key technology of the position differentiating method– the integer ambiguity resolution. Base on the known ambiguity range recursion scheme and varied scale coefficient which are used to optimize the search process, the least variance prior search method is introduced to deal with the large and tight correlation ambiguity range on the kinematic and long-baseline condition. It is shown that the method obviously improved the searching process and cut down about 2/3 of the search degree.Second, based on the research of the direct velocity and acceleration method, a technology using Kalman Filter to syncretize the carrier-phase information was introduced to realize the least variation estimation, and this technology improved the precision of acceleration. The real treatment indicated that on the 10 Hz data sample frequency, the acceleration precision of the static condition is 1.4 mm/s~2, and that of the kinematic condition is 398 mm/s~2.