ASCAT Soil Moisture

This report presents a proposal for a new discrete global grid (DGG) that is recommended for implementation within IPF's software for processing scatterometer data and generating soil moisture products. The new grid is to improve the current adapted sinusoidal grid used within WARP4.0. An overview of the three main methods for implementing DGG'S; partitioning, tiling and subdivision, is presented and their benefits and limitations are discussed. Four candidate DGG's are selected which represent the current state of the art both within IPF's operational processing environments and within the larger scientific community. This includes the proposed SMOS grid. The candidate grids are assessed based upon a detailed set of requirements and considerations for operational processing of scatterome-ter data. A simple compliancy matrix determines that the best potential DGG is the QSCAT grid which was implemented by IPF for the extraction and processing of NASA's QuikSCAT scatterometer data. The report concludes with the presentation of the proposed WARP5 grid, which is an adapted geodetic grid based upon the GEM6 ellipsoid, and includes a detailed description on the grid generation and an assessment of intergrid distances. The present study was funded by the NWP SAF ii Related Documents For more information relating to IPF's work concerning the derivation of Soil Moisture products from ASCAT data the reader is directed to the reports detailed in Table 1–1.