achieved, as contrasted to the previous altitude performance of 19,000 feet. This greater altitude capability permits us to utilize the majority of the wave clouds that frequently occur over the Mount Rose area. These wave clouds provide ideal "atmospheric laboratory" conditions due to their stationary configuration in space. Work plan B. Perform field experiments in cloud nucleation in the Elko and Reno area Elko.—The existing cloud-seeding program is continuing in the Elko area. No significant design changes have occurred in this program during the reporting interval. The radiosonde has been installed at Elko. This will greatly aid in the statistical analysis of seeding results. Mount Rose.-No seeding experiments have been conducted. Work plan C. Investigate the feasibility of a weather surveillance radar network in the Western United States As noted in Letter Progress Report No. 3, personnel of the Weather Bureau Research Station, Las Vegas, Nev., obtained information on precipitation in the Elko area by photographing a PPI presentation of the FAA Battle Mountain radar. The actual photographing was done in the Salt Lake ARTCC Center since the output of the Battle Mountain radar is microwaved to Salt Lake. The data was obtained by using a Polaroid camera to photograph a Bright Display. A Bright Display is a TV-type presentation of radar data stored on a storage tube. The technique is as follows: The radar output is read into one side of a storage tube and stored there for a period up to 6 minutes (as determined by the operator). The stored data is scanned and displayed on what are essentially conventional TV receivers. As noted previously one of the major advantages of the FAA system is the use of MTI (moving target indication) to eliminate ground clutter. This is especially advantageous in the mountainous areas of the West. A second advantage of the FAA system is the use of video mapping. This presents easy identification of the areas of interest by correlating the video maps with airways charts. Both the above features, the use of MTI and video mapping can be noted in the enclosed photographs figures A through F. 59-528-66-pt. 1 |