Radar Study Could Help Pilots Avoid Icing
Scientists at the National Center for Atmospheric Research (NCAR) in Boulder, Colo., are testing a new system this month that may pinpoint the location of water droplets in clouds that cause icing, potentially enabling pilots to avoid dangerous areas, the center announced yesterday. The system, known as S-Polka, combines two existing radars that use different wavelengths. By studying the differences between the images that are reflected back to each radar, scientists hope to find tiny water droplets that are difficult to distinguish using either radar alone. "This will take out a lot of the guesswork," said Marcia Politovich, director of the NCAR's icing program. "We think it will show exactly where the water is. That information could ultimately turn into an important warning system for pilots." Scientists and engineers at the NCAR are deploying S-Polka through the end of March at the NCAR's Marshall facility, southeast of Boulder. The system consists of a powerful polarized radar, known as S-Pol, which operates at a frequency of 3,000 MHz, and a polarized Ka-band radar, which operates at 35,000 MHz. The two radars have been mounted on a single pedestal. They are precisely aligned to look at the same area at the same time. Researchers will compare the radar images with data collected from a University of North Dakota Citation research airplane flying in the test area to determine whether the radar system is pinpointing water droplets. After data are collected this month, the researchers will focus on identifying and measuring droplets within the radar images accurately. If all goes well, the instrument will undergo final tests in a couple of years before being made available to airports. The project is funded by the National Science Foundation and the FAA.