The Use of Digital Radar in Short-Range Forecasting.
Abstract
As part of a program to improve short-range forecasts of weather conditions at aircraft terminals, a digital radar system was established at Air Force Geophysics Laboratory, Bedford Mass. The system, consisting of AN/FPS-77, digital interface, microwave transmitter-receiver, video integrator and computer, was installed in late 1972. Since that time the system has been used in conjunction with a network of 26 automated weather stations to make experimental forecasts of visibility and severe-weather conditions. The radar output of digital maps of radar intensity was found to be very convenient, but the inability of the radar to detect small water droplets limits the use in low visibility forecasting primarily to heavy rain storms and snow storms. In severe storms modest success was attained forecasting gusts, using digital maps. The large amounts of weather information from the network and radar frequently saturated the forecaster making forecasts at 15-min intervals, and relief was sought in the form of objective aids. Preliminary relationships between radar intensity, extinction coefficient (visibility) and rainfall rate have been formulated. In addition, a technique was developed using digital radar maps to obtain motion vectors and make probability forecasts of severe weather conditions. The calibration procedure relies on intensity of ground targets (hills and towers) for day-to-day relative calibration, and absolute calibration has been limited to Z-R relations. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 04, 1976
- Accession Number
- ADA033624
Entities
People
- H. Stuart Muench
- William E. Lamkin
Organizations
- Air Force Research Laboratory