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In its “Decadal Survey” of earth science missions for NASA published in 2007 [1] the U.S. National Research Council (NRC) recommended that a geostationary microwave sounder be developed for a Precipitation and All-weather Temperature and Humidity (PATH) mission and recommended that it be implemented as an “array spectrometer”. That was largely based on a synthetic-aperture concept then under development...
The Cyclone Global Navigation Satellite System (CYGNSS), selected as part of NASA's Earth Venture program and launching in 2016, will use an 8 observatory micro-satellite constellation to enhance the understanding of tropical cyclone intensity development. Operating the CYGNSS constellation in a cost effective manner is a fundamental cornerstone of achieving significant science return in a cost-constrained...
Proposed approaches to the NRC Earth Science Decadal Survey's Precipitation, All-Weather Temperature, and Humidity (PATH) mission involving synthetic aperture arrays require massively parallel, high speed correlators implemented on a geostationary satellite platform. We present testing methodology for a coarse digital correlator chip using a low-power ASIC architecture. The chip was designed in the...
NASA's first Earth Venture mission, the NASA EVM-1 Cyclone Global Navigation Satellite System (CYGNSS), is designed to provide data that will enable the study of the relationship between ocean surface properties, moist atmospheric thermodynamics and convective dynamics. These relationships are postulated to be intrinsic to the genesis and intensification of tropic storms. Key information about the...
This paper presents the development of the attitude determination and control system design of the Cyclone Global Navigation Satellite System spacecraft. The CYGNSS constellation consists of eight small satellite observatories in 500 km circular orbits at an inclination of 35 deg released from a single launch platform. Each CYGNSS spacecraft will make frequent and accurate measurements of ocean surface...
One of the greatest challenges in the evaluation of microwave radiometer RFI detection methods is a lack of suitable ground truth about the RFI environment; the false alarm rate can be readily estimated without it, but probability of detection cannot. A method is introduced to derive the probability distribution of RFI amplitude anywhere on the globe, thus characterizing the RFI environment. The method...
While hurricane track forecasts have improved in accuracy by ∼50% since 1990, there has been essentially no improvement in the accuracy of intensity prediction. This lack of progress is thought to be caused by inadequate observations and modeling of the inner core due to two causes: 1) much of the inner core ocean surface is obscured from conventional remote sensing instruments by intense precipitation...
As part of the EV-2 Cyclone Global Navigation Satellite System (CYGNSS) mission team, Surrey will be providing the Delay Doppler Mapping Instrument (DDMI) for eight Observatories designed and built by the University of Michigan and Southwest Research Institute (SwRI). Following the success of the GPS Reflectometry Experiment on the UK-DMC 1 satellite launched in 2003, Surrey has developed the SGR-ReSI...
Hurricane track forecasts have improved in accuracy by ∼50% since 1990, while in that same period there has been essentially no improvement in the accuracy of intensity prediction. One of the main problems in addressing intensity occurs because the rapidly evolving stages of the tropical cyclone (TC) life cycle are poorly sampled in time by conventional polar-orbiting, wide-swath surface wind imagers...
The NASA EV-2 Cyclone Global Navigation Satellite System (CYGNSS) is a spaceborne mission focused on tropical cyclone (TC) inner core process studies. CYGNSS attempts to resolve the principle deficiencies with current TC intensity forecasts, which lies in inadequate observations and modeling of the inner core. The inadequacy in observations results from two causes: 1) Much of the inner core ocean...
Bistatic remote sensing using L-band GPS signals has been proposed as an alternative to using microwave radiometers and monostatic radar scatterometers for spaceborne ocean surface windspeed measurements. L-band scattered signals are sensitive to waves with longer wavelengths than are the signals sensed by conventional radiometers and scatterometers, which typically operate at higher frequencies....
This paper describes the end-to-end simulation of the new HIRAD, which will provide improved hurricane surveillance. This paper (part-2 of 2) evaluates the HIRAD instrument performance in retrieving hurricane-force wind speeds in the presence of intense rain. Examples of retrieved hurricane wind speed and rain rate images are presented, and comparisons of the retrieved parameters with the MM5 numerical...
The vicarious cold and warm calibration methods of Ruf, and Brown and Ruf, have been used to assess the calibration of the WindSat radiometer as well as the biases of the TMI, SSM/I F13 and SSM/I F14 radiometers relative to WindSat. WindSat biases computed as a function of scan position are consistent with a roll offset of the instrument of 0.2?? and a pitch offset of 0.15??, and biases in the 6 GHz...
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