Determination of Sea Level Height Variation by Dynamics Crossover Adjustment

Abstract

The satellite radar altimeter surveys global mean sea level height continuously. The crossover point adjustment is based on the ascending-tracks and the descending-tracks of satellite orbit. According to the dynamic model of the altimetry satellite motion, the method of dynamic crossover point adjustment is introduced in this paper. It is the fact that the altimetry data sets in the crossover points are just as the repeated observations which constructs the basis of the crossover adjustment. Assume that h₀ is a sea level height variation, $\Delta \bar X_j^d$ is the satellite orbit change at time $t_j^d , \Delta \bar X_i^a$ is the satellite orbit change at time t ^a _i , h ^ad _ij is the undulation of the sea level height in the crossovers of the ascending-tracks and the descending-tracks. The sea level height variation ih ₀ can be gained by least-squares adjustment procedure. By establishing the dynamic model of crossover adjustment, the orbit errors could be reduced or weaken, thus improves the accuracy of the sea level height variation determined.