Global ice and land climate studies using scatterometer image data

Abstract

Scatterometers have provided continuous synoptic microwave radar coverage of the Earth from space for nearly a decade. NASA launched three scatterometers: the current SeaWinds scatterometer onboard QuikSCAT (QSCAT, 13.4 GHz) launched in 1999; the NASA scatterometer (NSCAT, 14.0 GHz), which flew on the Japanese Space Agency's ADEOS‐1 platform during 1996–1997; and the Seasat‐A scatterometer system (SASS, 14.6 GHz), which flew in 1978. The European Space Agency's (ESA) 5.3‐GHz scatterometer (ESCAT) has been carried onboard both the ERS‐1 and ERS‐2 satellites since 1991. properties, including the phase state, of a particular surface type. Varying response from the surface also results from different polarizations, viewing angles and orientations, and radar frequencies. The wide swath of scatterometers provides near daily global coverage at intrinsic sensor resolutions that are generally between 25–50 km.

Response of African humid tropical forests to recent rainfall anomalies

“…QSCAT is an active radar sensor operating in microwave frequency (13.4 GHz) and provides daily (6.00 and 18.00) measurements of the backscatter signal from the top layer of the forest canopy. QSCAT observations are not impacted by cloud cover, atmospheric aerosol and radiation condition, and are sensitive to the structure and water content of forest canopy, providing a reliable remote sensing technique rstb.royalsocietypublishing.org Phil Trans R Soc B 368: 20120306 to monitor impact of climate on tropical forests [17,18,26]. Given the high frequency (2.2 cm) and the steep incidence angle (468-548) of the QSCAT radar, the backscatter measurement over dense tropical forests is sensitive only to the top canopy structure and moisture and has relatively no information about the underlying soil moisture [27][28][29][30][31] (see the electronic supplementary material).…”

Melt Detection in Antarctic Ice Shelves Using Scatterometers and Microwave Radiometers

“…Scatterometers were originally developed and flown to observe near-surface wind over the ocean [13] but are useful in a variety of terrestrial applications [14]. Scatterometer measurements are particularly sensitive to the water content of the illuminated surface.…”

“…Inasmuch as the time of day of observations may differ somewhat between the two sensors, sensor time-of-day acquisition may contribute to differences in the sensor responses. The QuikSCAT SIR image data used in this study are available from the NASA Scatterometer Climate Record Pathfinder (SCP) project [14], [21].…”

Sea Ice Monitoring by Remote Sensing

“…They have proven to be useful for observation of sea ice and many other marine and terrestrial parameters, although their prime objective is to measure ocean surface winds (Long et al 2001). A scatterometer transmits radar pulses and receives backscattered energy in the same way as the SAR, but is designed to give lower spatial resolution data from a range of azimuths, thereby giving wind direction.…”