Abstract

We propose to apply low cost single frequency GPS receivers, deployed in a dense array, to tomographic estimation of small scale three-dimensional (3-D) atmospheric water vapor fields. The proposed proof-of-concept experiment will be conducted during the Atmospheric Radiation Measurement (ARM) pr... Show moreWe propose to apply low cost single frequency GPS receivers, deployed in a dense array, to tomographic estimation of small scale three-dimensional (3-D) atmospheric water vapor fields. The proposed proof-of-concept experiment will be conducted during the Atmospheric Radiation Measurement (ARM) program’s Intensive Observation Period (IOP) of July 1999 near the Lamont Cloud and Radiation Testbed (CART). The system will utilize 25-30 GPS receivers deployed at 1 to 3 km spacing in a 10 x 10 km or larger area. Carrier phase data from this array will be analyzed to determine line-of-sight tropospheric delays caused by atmospheric water vapor. These line-ofsight delays shall be inverted, using tomographic techniques, and optionally first guess fields based on other atmospheric data available at the ARM CART site, to estimate 3-D atmospheric water vapor fields at 30 min or smaller time intervals. An alternative approach will be to assimilate the slant measurements into a high resolution numerical weather model like MM5. The purpose of the proposed effort is to develop and demonstrate a new atmospheric sensing technique to measure small scale atmospheric water vapor fields, which are important to provide the initial and boundary conditions for the Single Column Modeling (SCM) efforts conducted under the ARM program. Show less