Vertical Temperature Profile Radiometer (VTPR) Data

Summary

The Vertical Temperature Profile Radiometer (VTPR) was an operational 8-channel sounding system mounted on the NOAA-2 through NOAA-5 spacecrafts. The instrument made routine observations for deriving atmospheric temperature soundings. The measurement covered more than six years of observation from November 1972 to February 1979.

A thorough description of the VTPR instrument has been provided by McMillin et al. (1973). The instrument scans perpendicular to the satellite motion, from left to right facing the direction of travel, in 23 discrete steps. Fields of view, scanning times, and apparent motion on the earth provide spot pixels which are contiguous both across and along the orbital track. The VTPR sounder has a horizontal resolution of 55km x 57km at the nadir and 67km x 91km at the end of scan. The image to the right shows an example of VTPR channel 8 brightness temperature measurements taken from NOAA-5 during a 6-hour period starting at 0600 UTC, February 1, 1979.

Each file of the dataset contains six hours of VTPR measurement. To facilitate the understanding of each file!s general data characteristics, descriptive quality control statistics associated with each file are computed. Time series of the statistical plots are produced. Separate plots were created to show number of pixels in each file, the standard deviation of the channel brightness temperatures, and the mean, minimum, and maximum values. These are provided in PNG file and Postscript file formats.

Data Description

The data can be obtained through an OpenDAP server or through anonymous ftp.

Each of the VTPR files store six hours of data with the following filename format:

                        yyyymmddhhvtpr.nc

In which yyyy is for the four-digit year, mm for month, dd for date, and hh for GMT hour.

The following header information shows the variables included in each file:

dimensions:
             ch = 8 ;
             number = UNLIMITED ;
variables:
             int satid(number) ;
                        satid:long_name = "satellite_id" ;
             int instid(number) ;
                        instid:long_name = "instrument_id" ;
             float bt(number, ch) ;
                        bt:long_name = "brightness temperature" ;
                        bt:units = "Kelvin" ;
             float lat(number) ;
                        lat:units = "degrees_north" ;
                        lat:valid_range =  -90.,  90. ;
             float lon(number) ;
                        lon:units  = "degrees_east" ;
                        lon:valid_range = -180., 180. ;
             float number(number) ;
             float zen(number );
                        zen:long_name = "zenith" ;
             float alt(number) ;
                        alt:long_name = "altitude" ;
                        alt:units = "km" ;
             int line(number) ;
                        line:long_name = "line" ;
             int posi(number) ;
                        posi:long_name = "position" ;
             int year(number) ;
             int month(number) ;
             int date(number) ;
             int hour(number) ;
             int minute(number) ;
             int second(number) ;

Bibliography

McMillin, L.M., D. Q. Wark, J. M. Siomkajlo, P. G. Abel, A. Werbowetzki, L. A. Lauritson, J. A. Pritchard, D. S. Crosby, H. M. Woolf, R. C. Luebbe, M. P. Weinreb, H. E. Fleming, F. E. Bittner, and C. M. Hayden, 1973: "Satellite Infrared Soundings from NOAA Spacecraft". (2.5 Mb) NOAA Technical Report NESS 65.

Shi, L. and J. J. Bates, 2006: "Vertical Temperature Profile Radiometer Brightness Temperature Dataset and its Statistics". (206 Kb) 14th Conference on Satellite Meteorology and Oceanography, 86th AMS Annual Meeting, Atlanta, GA, 30 January - 2 February 2006, American Meteorological Society, Boston, MA, P2.1 (7 p.)

Shi, L., J. J. Bates, X. Li, S. Uppala, and G. Kelly, 2008: "Extending the Satellite Sounding Archive Back in Time: the Vertical Temperature Profile Radiometer Data". J. Appl. Remote Sens. Vol. 2, 023506

Contact

NOAA/NESDIS/National Climatic Data Center
Satellite Services Group
151 Patton Ave
Asheville, NC 28801
USA
E-mail: NCDC.satorder@noaa.gov
Phone: 1+828-271-4800
FAX: 1+828-271-4876