A data acquisition and control system (DACS) has been designed and constructed for use during propagation experiments with the OLYMPUS satellite. OLYMPUS is a European Space Agency experimental satellite that broadcasts coherent at 12, 20 and 30 GHz and is viewed from Blacksburg, Virginia at an elevation angle of 13.9°. This low elevation angle yields a relatively long atmospheric path which serves to accentuate propagation effects. The DACS is a custom design which collects propagation, environmental and status information and periodically calibrates external equipment. Beacon signal strength is measured via a hybrid analog/digital receiver. The analog portion the receiver utilizes the coherency of the satellite beacons to track 20 and 30 GHz signals to the noise floor. The digital portion of the receiver is contained within the DACS and consists of a stand-alone microprocessor which filters the beacon signal to determine the power in a 3 Hz bandwidth. Additional DACS circuitry collects analog and digital input channels and controls external through digital output channels. Digital outputs are used to reference the collected to known by performing periodic calibrations on external equipment. Analog input channels are used to measure quantities including external temperature, wind speed wind direction, while digital inputs monitor alarm conditions. The VIEW program utility permits an operator to graphically view data in real time. In addition, collected data is stored to tape without an interruption in data collection. DACS operation has been virtually continuous since data collection was started on August 3, 1990. / Master of Science

This paper presents a broad overview of the equipment and rational of the experiment conducted by the VPI Satellite Communications Group under INTELSAT Contract 433. The object of this experiment is to assess the validity of meteorological radar as a predictor of satellite earth-space path fade statistics. To validate the data collected by the VPI radar for this experiment, the differential reflectivity (ZDR) measured during the November 29-30, 1985 rainstorm is compared with calculated ZDR and ZDR from published plots. The special hardware and calibration techniques required for this experiment are also described. An IBM-PC controlled antenna pointing system and a system to continuously monitor both the peak and average power of the radar transmitter are included. Also included is a calibration system for the radar receiver. A simple computer program is developed which will give the radar cross section of a metal sphere. This sphere is used as a calibrated radar target. / M.S.

Indiana University-Purdue University Indianapolis (IUPUI)

Indiana University-Purdue University Indianapolis (IUPUI) / Over the past two decades, northern parts of the United States have experienced extreme heat conditions. Some of the notable heat wave impacts have occurred in Chicago in 1995 with over 600 reported deaths and in Philadelphia in 1993 with over 180 reported deaths. The distribution of extreme heat events in Indianapolis has varied since the year 2000. The Urban Heat Island effect has caused the temperatures to rise unusually high during the summer months. Although the number of reported deaths in Indianapolis is smaller when compared to Chicago and Philadelphia, the heat wave in the year 2010 affected primarily the vulnerable population comprised of the elderly and the lower socio-economic groups. Studying the spatial distribution of high temperatures in the vulnerable areas helps determine not only the extent of the heat affected areas, but also to devise strategies and methods to plan, mitigate, and tackle extreme heat. In addition, examining spatial patterns of vulnerability can aid in development of a heat warning system to alert the populations at risk during extreme heat events. This study focuses on the qualitative and quantitative methods used to measure extreme heat events. Land surface temperatures obtained from the Landsat TM images provide useful means by which the spatial distribution of temperatures can be studied in relation to the temporal changes and socioeconomic vulnerability. The percentile method used, helps to determine the vulnerable areas and their extents. The maximum temperatures measured using LST conversion of the original digital number values of the Landsat TM images is reliable in terms of identifying the heat-affected regions.