=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*= INTRODUCTION 7 August 1996 The ER-2 Doppler radar (EDOP) and the Advanced Microwave Precipitation Radiometer (AMPR) flew together aboard the NASA ER-2 during the CAMEX-2 field campaign in August 1995. The AMPR is a cross-track scanning instrument while the EDOP employs antennas fixed along the nadir plane. EDOP is an X-band radar (9.6 GHz) operated by NASA GSFC (PI: Gerry Heymsfield) while AMPR operates at 10.7, 19.35, 37.1, and 85.5 GHz and is a MSFC instrument (PI: Roy Spencer and Robbie Hood). Although Goddard is providing coregistered EDOP and AMPR data files, technical questions concerning the AMPR instrument should be directed to personnel at Marshall. EDOP AND AMPR MERGED DATA FILE The EDOP and AMPR coregistered data are stored as ASCII in a file which contains one vertical reflectivity profile per line. The first two lines of the file contain header information. The brightness temperatures are for the nadir view and the reflectivity is from the EDOP nadir antenna. ASCII was chosen in order to provide the easiest access to the data. The EDOP and AMPR data were coregistered in time by comparing the ER-2 pitch from the navigation data of the two instruments. Typically there was a lag of 0-1 EDOP dwells (0.5 s) to achieve a correlation of >0.998. After the EDOP data where shifted in time, an EDOP dwell was selected at the time of each AMPR scanline. This is possible because AMPR produces a scanline every 3 seconds while EDOP generates a dwell (vertical range profile) each 0.5 second. The files contain the brightness temperatures in the nadir direction for 10, 19, 37, and 85 GHz. The vertical profile of reflectivity from EDOP follows after the temperature data. The EDOP data are the unaltered radial data relative in height to the surface echo. Therefore, ER-2 navigation (pitch, roll, ground speed, altitude) is included to assist in registration in space along the track. General File Format =================== Line 1 DATE Line 2 HOUSEKEEPING Line 3 DWELL/SCANLINE 1 Line 4 DWELL/SCANLINE 2 [....] Line n+2 DWELL/SCANLINE n Line Description ================ DATE: day month year HK: ngates gate-width gate-avg dwell-avg flag zthold zfield DWELL: time pitch roll ground speed altitude TBB-list dBZ-list Format Specifiers (i=Integer, f=Float, x=Space) =============================================== DATE: 2(i2.2, 2x), i4 HK: i3, 2x, f6.1, 2x, i3, 2x, i2, 2x, f7.2, 2x, f6.2, 2x, a2 DWELL: 3i2.2, 2x, f6.2, 2x, f6.2, 2x, f6.2, 2x, f7.1, 3x, 4(f6.2, 1x), $ 3x, NGATES(f6.2, 1x) (Where NGATES, number of gates, is given in the HK line, e.g. 205) Units o Gate width [meters] o INS pitch and roll [degrees] o INS ground speed [m/s] o GPS altitude [meters] o Brightness temperatures [degrees Kelvin] o Reflectivity threshold [dBZ] o Reflectivity [dBZ] Notes o The order of the brightness temperatures is: 10 19 37 85 GHz o The first gate of reflectivity is the surface (height = 0 km) o The day and month are two digits; the year is four digits o The time from GPS on each line is UTC: hhmmss o Missing or thresholded reflectivity has a value given by the FLAG field o Typically, the first two range gates are contaminated by surface clutter LIST OF FILES The selected flight tracks are provided in a compressed UNIX tar file. To extract the data files the following steps must be performed. 1) Uncompress: uncompress edopampr.tar.Z 2) Extract: tar -xf edopampr.tar The extracted files are: 950828_2203.mrg EDOP/AMPR coregistered data, 28 Aug 95, 2203 UTC 950828_2203.gif Combined EDOP nadir reflectivity and AMPR Tb image 950828_2306.mrg EDOP/AMPR coregistered data, 28 Aug 95, 2306 UTC 950828_2306.gif Combined EDOP nadir reflectivity and AMPR Tb image 950828_2331.mrg EDOP/AMPR coregistered data, 28 Aug 95, 2306 UTC 950828_2331.gif Combined EDOP nadir reflectivity and AMPR Tb image README.merge This file CONTACTS EDOP: Dr. Gerry Heymsfield Mesoscale Atmospheric Processes Branch (Code 912) NASA Goddard Space Flight Center Greenbelt, MD 20771 Phone: 301-286-6369 Fax: 301-286-1762 Email: heymsfie@carmen.gsfc.nasa.gov AMPR: Ms. Robbie Hood Global Hydrology and Climate Center 977 Explorer Blvd Huntsville, AL 35806 Phone: 205-922-5959 Fax: 205-922-5801 Email: robbie.hood@msfc.nasa.gov =*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=