|
|
CAMEX-4 MIPS 915 MHz Doppler Wind Profiler Table of Contents
The University of Alabama in Huntsville (UAH) Mobile Integrated Profiling System (MIPS) includes a 915 MHz Doppler profiler, lidar ceilometer, 12 channel microwave profiling radiometer, Doppler Sodar, Radio Acoustic Sounding System (RASS), Field Mills, and surface observing stations. This dataset consists of data derived from the 915 MHz Doppler Wind Profiler as described below. Instrument DescriptionThe 915 MHz antenna is an electrically steerable micropatch phased array, formatted by four 0.9 m and 0.9 m antenna panels. In order to derive the full three-dimensional wind vector, observations must be made using a minimum of 3 non-coplanar beam pointing directions. This is accomplished in the current system that has five fixed beams, one at zenith, and four beams 23 deg from zenith in orthogonal directions. Profiling is achieved using a technique known as Doppler Beam Swinging (DBS) which involves making observations in a cyclic sequence of vertical and near-vertical beam pointing directions. The 'targets', from which small fractions of the pulsed radar signals are returned, are irregularities of atmospheric refractive index, which cause back-scattering (so-called 'clear-air' returns), and hydrometeors, which give rise to Rayleigh scattering. The scattered signal is Doppler-shifted according to the radial component of the target's velocity, i.e. that along the radar beam pointing direction. By sampling the radar return signals as a function of delay from the time of the transmitted pulse, range to the target is measured with the transmitted pulse length determining the range resolution. With the 9 deg beamwidth, the sample volume width is approximately 15% the value of range. Thus, at a height of 4 km, the width of the sample volume is ~600 m. There are several web sites which give excellent descriptions of Doppler Wind Profiling systems. On such is found at the Mesosphere-Stratosphere-Troposphere Radar Facility at Aberystwyth in the UK. Data ProductsThere are three files produced per day for the MIPS Profiler. One is a file named W01ddd.CNS, where ddd is the day of year. This is 'consensus' file, (hence the extension) and is in ASCII. There are two additional files whose names are of the form D01dddA.SPC or H01dddA.SPC; again, where ddd is the day of year. These are spectral data files. These files are in binary format, and are D indicates a data file, and H indicates a header file. Data FormatData is stored in daily tar files of the form
where ddd is the day of the year. When untarred, this file yields three files described above:
The .CNS file is a text file, and the .SPC files are binary. Formatting descriptions are found in the document distributed with the dataset called How the Profiler software works.pdf, which is also available via the preceding link. This particular document comes from the operator's manual. Contact InformationThe data producer is:
To order these data or for further information, please contact:
|