These data were calibrated with the old calibration figures. The most recent calibration (as of 11 May 1999, documented here) has revealed that 2 dB should be added to all 35 and 94 GHz (and 95 GHz GKSS) reflectivity values on this site.
Since the data is averaged over a number of seconds in real time, the profiles are the nearest in time to the aircraft overheads (where these are known). The heights correspond to the centres of the range gates and are above mean sea level, although the accuracy is no better than the pulse length of the radar, which is of same order as the range-gate spacing. The contribution to the measured signal from noise has been subtracted.
On some occasions the aircraft were detected; this is indicated next to the links below. Profiles including a hits on the C-130 in cloud are accompanied by the adjacent profiles so that interpolation can be performed (if required) to estimate the reflectivity of the cloud in the direct vicinity of the aircraft itself.
Most of the profiles taken at 35 GHz were from `fixed' dwells at vertical in between RHIs. The raw temporal resolution of these data was around 0.25 seconds, but 5 second averaging has been performed to increase sensitivity. The range resolution of these data is 225 metres. These files can be found in the subdirectory 35_s.
Some of the profiles were recorded in vertically-pointing mode, the mode used for unattended operations. The temporal resolution of these data was 10 seconds, and the spatial resolution was 75 metres. These profiles are indicated below with `(75 metre range resolution)', and can be found in the subdirectory 35_v.
The 94 GHz data had a temporal resolution of 10 or 20 seconds and a spatial resolution of 60 metres. It should be noted that some rays were `glitched' at 94 GHz when the ARAT aircraft was overhead, probably because of interference with the KESTREL radar, although there was an intermittent technical fault which caused similar glitching on other occasions. Where the nearest ray to an overhead has been corrupted, the nearest uncorrupted ray is provided instead. These files can be found in the subdirectory 94_v.
Each data file consists of a single profile of radar reflectivity at a single wavelength, in simple ascii format. The files are not compressed or zipped. The first line contains two numbers; the first is the number of range gates used, and the second is the time of the profile in decimal hours UTC (also indicated in the filenames as hhmmss). The remainder of the file is two columns of numbers corresponding to the height of the centre of range gate in kilometres and the radar reflectivity in dBZ.