Validating ionospheric models with measured electron density profiles

On behalf of an URSI Working Group 3 initiated study (VIM), three ionospheric models, IRI, PL/PRISM and FLIP, are compared with electron density profiles derived from ionograms Millstone Hill. Four months of data in 1989/90 were analyzed. For most of the time, N(h) profiles were available every 15 minutes providing a good statistical database for the evaluation of the ionospheric models in terms of diurnal and seasonal variations.     

Satellite-derived synoptic climatology in data-sparse regions

Synoptic-scale “moisture bursts” are defined, based on infrared GOES imagery, and their synoptic climatology is developed. Quantitative analysis of satellite-derived individual channel radiance data and vertical eigenfunctions of complete channel data yield rich structural detail; these details do not appear in FGGE analyses in regions void of conventional meteorological data.     

Transrapid MagLev Update

The Transrapid MagLev had been under development in West Germany for a number of years under the sponsorship of the Ministry of Research and Technology. Following a number of experimental and demonstration vehicles, two prototype 250MPH 100-passenger inter-city vehicles, TRO6, were built, along with an elaborate 20-mile test facility where revenue service can be simulated. Following a period of initial testing by the Transrapid consortium, the operation of the test facility was turned over to a consortium of the German airlines (Lufthansa), German railroad (DB) and a testing house. This consortium is evaluating the suitability of the Transrapid MagLev for revenue service under the complete range of operating conditions. At this time, approximately 200 runs have been made, for a total of 7,000 miles at speeds up to 220MPH (the maximum achievable until the completion of the southern loop.)     

Laser Doppler Velocimeter Development

A new two-channel laser Doppler velocimeter developed for the Ames High Reynolds Channel No. II is described. Design features required for the satisfactory operation of the optical system in the channel environment are discussed. Fiber optics are used to transmit the megahertz Doppler signal to the photodetectors located outside the channel pressure vessel, and provision is made to isolate the optical system from pressure and thermal strain effects. Computer-controlled scanning mirrors are used to psoition the laser beams in the channel flow. Techniques used to seed the flow with 0.5-?-diam polystyrene spheres avoiding deposition on the test-section windows and porous boundary-layer removal panels are described. Preliminary results are presented with a discussion of several of the factors affecting accuracy.     

Digital Cartographic Data: A Case for Electronic Delivery

The demand for digital cartographic data and information is expanding rapidly, most dramatically in navigation. Electronic chart and map display systems are now reaching the market for land, sea and air navigation and rapid delivery of the latest data is absolutely essential. Commercial aviation is moving rapidly toward the automated cockpit with the new generation Flight Management Computer System. Marine navigation is experiencing a similar growth in integrated navigation systems and every major automobile manufacturer has plans for digital map navigation systems. The largest, most complete data bases to meet these requirements are Government held and difficult to access, thus most private sector firms re-digitize and agencies maintain near duplicate data. Present inefficiencies, introduced errors, and delays stem from lack of rapid access and delivery of digital data. Use of newly developed satellite data broadcast technology offers a solution.