Case Study Analysis of Clustering Applied to VAS Measurements

摘要

A joint effort is underway to test a technique for clustering satellite soundingmeasurements (Hillger and Purdom, 1990) that was developed at the Cooperative Institute for Research in the Atmosphere (CIRA) and applied to VISSR Atmospheric Sounder (VAS) data ingested at the Forecast Systems Laboratory (FSL). Clustering offers the advantage of increasing signal-to-noise by averaging of measurements which are similar to within the noise levels of the VAS instrument. A case study day was chosen, which differs in two ways from previous tests of clustering on VAS. One difference was that measurements in selected VAS channels are not available for all horizontal scans of the satellite. The second difference was this case study included cloud-contaminated FOVs (Field-of-View) along with clear FOVs. Findings from the study are the nearest to a real-time test that has been done. Results will define some of the advantages and disadvantages of clustering as compared to arbitrary blocking of VAS measurements which is presently used for operational satellite sounding production.