Estimation of Lake Level Using Tiangong-2 InIRA Data

Abstract

Tiangong-2 space laboratory, launched on 15 September, 2016, carries an Interferometric Imaging Radar Altimeter (InIRA). InIRA can conduct interferometry of ocean and land with high precision and wide swath. In this study, nine Qinghai-Tibet Plateau lakes are selected to analyze the preliminary performance of lake level estimation using the InIRA data. Based on bias and standard deviation of estimated lake level, the lake levels obtained from InIRA Level1 data (InIRA lake levels) are compared with the lake levels directly derived from Cryosat-2 Synthetic Aperture Radar interferometry (SARin) Level1b (L1b) data, and the accurate lake levels obtained from the retracking Cryosat-2 SARin L1b data. The results show that the bias of absolute InIRA lake levels is 4.105 m, and the mean standard deviation of InIRA point lake levels is 1.063 m. It indicates that InIRA Level1 data is more stable than Cryosat-2 SARin L1b data and relative lake levels with high precision can be expected to estimate using the further processed InIRA data.