|
The Advanced Microwave Precipitation Radiometer (AMPR) has just completed a number of successful field deployments and will be refitted with a number of improvements to allow for improved calibration measurements and enhanced data processing. The AMPR is sponsored by NASA at the Marshall Space Flight Center for the investigation of precipitation using passive microwave brightness temperatures from the NASA ER-2 high altitude aircraft. The primaiy goal of the AMPR is the exploitation of the scattering signal of precipitation at frequencies near 18, 37, and 85 GHz together to unambiguously retrieve storm precipitation structure and intensity information from high in the storm (85 GHz) to deep within the storm (18 GHz). The instrument is a total power radiometer using a cross track scanning technique to gather data at four separate frequencies. The four center frequencies, 10.7, 19.35, 37.10, and 85.50 GHz. are separated into two feedhorns. The 10.7 GHz. being the larger diameter horn, drives the placement and position of the loads and the three remaining frequencies are contained in a multifrequency feedhom The previous load material used in the initial instrument deployments for the hot and cold loads were found to.be difficult to maintain at a uniform elevated temperature, causing gradients through the material. With the uncertainty in sensed temperatures versus radiometer brightness temperatures a set of new loads were developed and installed. Also, with the harsh environment in which the instrument flies, the data system needed to be revised. With the current data rates, a tape system was not selected to help minimi7.e the mechanical suscepubility to the high condensation seen by the instrument and electronics on landing. A flash RAM approach will be used to store the data during each flight at a modest rate of 160 words/sec. Future growth in the data system will allow increased data throughput and capacity for J<OSS1Dle dual-polari7.ation applications. Ground station computers will take :flash RAM cards and ingest the data for quick view presentation and initial data analysis for next day flight preparation.
|
