The Envisat Radar Altimeter System (RA-2)
نویسنده
چکیده
The mission RA-2 has an essential role to play in the Envisat mission, as indicated in Table 1. Operating over oceans, its data can be used to monitor seasurface topography, thereby supporting research into ocean circulation and sea-level change, as well as providing observations of the sea floor structure or shape, and marine geoid characteristics. It will also be possible to determine near-sea-surface wind speeds and significant wave heights, data that are important for both weather and sea-state forecasting. RA-2 will also be able to map and monitor sea ice and polar ice sheets, allowing the energy/mass balances of the world’s major ice sheets, including the Antarctic, to be better determined.
منابع مشابه
Near Real Time Global Lake and River Monitoring Using the Envisat Ra-2
Over the past 18 months, a pilot system has been developed which has generated global lake and river level measurements from the Envisat RA-2. These data are produced within 3-5 days of measurement, using retracked Level 1B altimeter echoes merged with data from the IGDR to obtain both orbit and atmospheric/instrument corrections. A global version of this system has now been in operation for ov...
متن کاملRa-2/mwr Cross-calibration and Validation: Objectives, Approach, Results and Recommendations
ENVISAT carries a new generation radar altimeter (RA-2) and a microwave radiometer (MWR). RA-2 provides improved measurement performances and many new capabilities, which will benefit the science and application community. With almost two decades of altimetric measurements acquired by ESA, long-term evolution of parameters playing a key role in climate change can be addressed. This requires hom...
متن کاملKu-band Radar Altimeter Surface Wind Speed Algorithm
An algorithm for the retrieval of surface wind speed from Ku-band altimeter backscatter coefficient is proposed. The algorithm was derived using two-month worth of ENVISAT altimeter backscatter data collocated with ECMWF model and buoy wind speeds. The algorithm was extensively verified for ENVISAT, ERS2 and Jason-1 altimeters. The algorithm performance is better than the “modified Chelton-Went...
متن کاملGlobal Inland Water Monitoring from Satellite Radar Altimetry – a Glimpse into the Future
The capability of satellite radar altimeters to monitor the height changes of major lakes is well established. However, river systems present far more challenging targets. By retracking altimeter echoes using an expert system approach, river heights can be successfully monitored; this capability is bounded by the along-track sampling rate. However, a glimpse into the potential of future altimet...
متن کاملEffects of Snow Properties on the Dual Frequency Radar Altimeter Signal of Envisat over the Antarctic Ice-sheet
A unique advantage of the ENVISAT altimeter system is the acquisition in S band as well as the classical Ku band. This S band frequency is designed to measure the ionospheric delay over the ocean surfaces. Over land and ice, however, the returned radar echo differences between the two frequencies are also function of the properties of the sensed medium. This is particularly the case over the An...
متن کامل