Numerical Preprocessing of Rawinsonde Position Vectors

摘要

Martin-Graham filters are used subsequent to correction for erroneous data points to smooth the rawinsonde set AN/GMD-4 spherical measurements. This smoothing produces not only a corrected wind profile but also allows an orderly pressure integration of the hydrostatic equation. The major data problems besides high frequency elevation-angle noise include range jumps and diffraction phenomena. The range jumps are identified and corrected through the inspection of first and second differences in the range field. The diffraction phenomena are adjusted by assuming a linear change in the balloon-ascent-rate field and reconstructing the elevation angles. Erroneous data due to other causes are adjusted by comparing filtered with raw data and imposing limitations on the height, wind, and position vector fields. (Author)