GPS estimation of atmospheric water vapour from a moving platform

Measuring water vapour content, and its variability, in the atmosphere is i mportant for meteorological and climatological research. Recently, a techni que for the remote sensing of water vapour in the atmosphere using ground-b ased GPS has been rapidly developed. An estimation accuracy for integrated water vapour content of 1-2kg/m(2) has been routinely available from such g round-based GPS networks (Dodson and Baker, Proceedings of the ION National Technical Meeting, Navigation 2000, California, January 21-23). Extending this technique into the sea on a moving platform would be greatly beneficia l for meteorological research, such as the calibration of satellite data an d the investigation of the sea/air interface as well as forecasting and cli mate studies. However, whether the water vapour can be separated from the m otion of the GPS receiver in the estimation process itself, is still an ope n question. In this paper, a new method, based on a Kalman filter, has been developed to deal with this problem. The initial experiment shows that the accuracy of estimated tropospheric delay from a moving platform is compara ble to that froth (static) land based receivers. (C) 2001 Elsevier Science Ltd. All rights reserved.