The neural network algorithm in this paper is applied to the ocean surface wind speed retrievals. Firstly, the Ku band backscattering coefficient (σKu) is considered as the input parameter to retrieve the wind speed and the retrieval precision reaches 1 m/s (root mean square error) for HY2 altimeter. Secondly, by introducing the Ku-band significant wave height (swhku), C-band backscattering coe...

A full-spectral third-generation ocean wind-wave model, Wavewatch-III, has been implemented in the South China Sea (SCS) for investigating the wind wave characteristics. This model was developed at the Ocean Modeling Branch of the National Centers for Environmental Prediction (NCEP). The NASA QuickScat data (0.25 resolution) two times daily were used to simulate the wind waves for the whole yea...

This paper describes the design, development, and operation of a research Unmanned Aerial Vehicle (UAV) system that has been developed at the Georgia Institute of Technology, called the GTMax. This description will include the processes put in place to enable the system to be used for UAV-technology research, including effective flight testing. Research UAVs are characterized by the need for co...

This paper describes the Ka-band altimetry payload and system that has been studied for several years by CNES, ALCATEL SPACE and some science laboratories. Altimetry is one of the major elements of the ocean observing system to be made sustainable through the GEOSS (Global Earth Observation System of Systems) and GMES (Global Monitoring of the Environment and Security) programs. A short review ...

Conventional terrain-aided navigation (TAN) technique uses an altimeter to locate the position of an aerial vehicle. However, a major problem with a radar altimeter is that its beam (or pulse) footprint on the ground could be large, and therefore the nadir altitude cannot be estimated accurately. To overcome this difficulty, one may use the nadir-looking synthetic aperture radar (SAR) technique...

Observations of sea surface height reveal that substantial changes have occurred over the past decade in the mid- to high-latitude North Atlantic Ocean. TOPEX/Poseidon altimeter data show that subpolar sea surface height increased during the 1990s, and the geostrophic velocity derived from altimeter data exhibits declining subpolar gyre circulation. Combining the data from earlier satellites, w...

We have conducted airborne measurements over the Greenland ice sheet from the NASA P-3B aircraft using a 150MHz coherent radar depth sounder to obtain extensive ice sheet thickness measurements. Simultaneous measurements of ice sheet elevation were also made using a laser altimeter. In outlet glacier areas along the ice sheet margin, the ice surface is characterized by a very rough, crevassed s...

1589. Lunar and Planetary Institute, Houston. [CD-ROM] Zuber, M. T., D. E. Smith, R. J. Phillips, S. C. Solomon, W. B. Banerdt, G. A. Neumann, and O. Aharonson 1998a. Shape of the northern hemisphere ofET AL. Mars from the Mars Orbiter Laser Altimeter (MOLA). Geophys. Res. Lett.25, 4393–4396. Zuber, M. T., D. E. Smith, S. C. Solomon, J. B. Ashire, R. S. Azfal, O. Aharonson, K. Fishbaugh...

The surface topography of the Greenland and Antarctic ice sheets is the principal ice parameter obtainable from satellite radar altimetry. The improved ability of the GEOSA T altimeter to follow irregular surfaces and its extended operation have greatly increased the available topographic data on ice sheets for the study of ice dynamics and the possible detection of changes in global ice volume.