Author: National Aeronautics and Space Administration (NASA)Publisher: Createspace Independent Publishing Platform
ISBN: 9781722941369
Category :
Languages : en
Pages : 142
Book Description
High resolution windspeed profile measurements are needed to provide reliable detection of hazardous low altitude windshear with an airborne pulse Doppler radar. The system phase noise in a Doppler weather radar may degrade the spectrum moment estimation quality and the clutter cancellation capability which are important in windshear detection. Also the bias due to weather return Doppler spectrum skewness may cause large errors in pulse pair spectral parameter estimates. These effects are analyzed for the improvement of an airborne Doppler weather radar signal processing design. A method is presented for the direct measurement of windspeed gradient using low pulse repetition frequency (PRF) radar. This spatial gradient is essential in obtaining the windshear hazard index. As an alternative, the modified Prony method is suggested as a spectrum mode estimator for both the clutter and weather signal. Estimation of Doppler spectrum modes may provide the desired windshear hazard information without the need of any preliminary processing requirement such as clutter filtering. The results obtained by processing a NASA simulation model output support consideration of mode identification as one component of a windshear detection algorithm. Lee, Jonggil Unspecified Center AIRBORNE EQUIPMENT; DETECTION; HAZARDS; METEOROLOGICAL RADAR; PULSE DOPPLER RADAR; SIGNAL PROCESSING; STATISTICAL ANALYSIS; WEATHER; WIND SHEAR; WIND VELOCITY; ALGORITHMS; CLUTTER; ERRORS; ESTIMATES; ESTIMATING; HIGH RESOLUTION; LOW ALTITUDE; LOW FREQUENCIES; SIMULATION; SPECTRA...