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Azimuthal Modulation Of C-Band Scatterometer Over Southern Ocean Sea Ice, David G. Long, David S. Early
Azimuthal Modulation Of C-Band Scatterometer Over Southern Ocean Sea Ice, David G. Long, David S. Early
Faculty Publications
In a continuing evaluation of the ERS-1 C-band scatterometer as a tool for studying polar sea ice, the authors evaluate the azimuthal modulation characteristics of Antarctic sea ice. ERS-1 AMI scatterometer mode data sets from several study regions dispersed in the Antarctic seasonal sea ice pack are evaluated for azimuthal modulation. When appropriate, the incidence angle dependence is estimated and removed in a study region before determining whether azimuthal modulation is present in the data. Other comparisons are made using the fore and aft beam measurement difference. The results show that over the ice pack, azimuthal modulation is less than …
Radar Backscatter Measurement Accuracy For A Spaceborne Pencil-Beam Wind Scatterometer With Transmit Modulation, David G. Long, Michael W. Spencer
Radar Backscatter Measurement Accuracy For A Spaceborne Pencil-Beam Wind Scatterometer With Transmit Modulation, David G. Long, Michael W. Spencer
Faculty Publications
Scatterometers are remote sensing radars designed to measure near-surface winds over the ocean. The difficulties of accommodating traditional fan-beam scatterometers on spacecraft has lead to the development of a scanning pencil-beam instrument known as SeaWinds. SeaWinds will be part of the Japanese Advanced Earth Observing Satellite II (ADEOS-II) to be launched in 1999. To analyze the performance of the SeaWinds design, a new expression for the measurement accuracy of a pencil-beam system is required. In this paper the authors derive a general expression for the backscatter measurement accuracy for a pencil-beam scatterometer which includes the effects of transmit signal modulation …
Tradeoffs In The Design Of A Spaceborne Scanning Pencil Beam Scatterometer: Application To Seawinds, David G. Long, Chialin T. Wu, Michael W. Spencer
Tradeoffs In The Design Of A Spaceborne Scanning Pencil Beam Scatterometer: Application To Seawinds, David G. Long, Chialin T. Wu, Michael W. Spencer
Faculty Publications
SeaWinds is a spaceborne wind scatterometer to be flown on the second Japanese Advanced Earth Observing Satellite (ADEOS-II) in 1999. An important international element of NASA's Earth Observing System (EOS), SeaWinds is an advanced follow-on to the NASA scatterometer (NSCAT) on the first ADEOS platform. Unlike previous operational spaceborne scatterometer systems. SeaWinds employs a scanning "pencil-beam" antenna rather than a "fan-beam" antenna, making the instrument more compact and yielding greater ocean coverage. The goals of this paper are twofold. First, the overall SeaWinds functional design and backscatter measurement approach are described, and the relative advantages of the pencil-beam technique are …