(this document is based on the readme document available at NASA/Marshall's Global Hydrology web page: http://ghrc.msfc.nasa.gov/uso/readme/ampr.html

Data Set Overview

The Advanced Microwave Precipitation Radar (AMPR) data sets of Texas & Florida Underflights field experiments (TEFLUN A & B) are part of the aircraft based measurements collected in support of the TRMM ground validation efforts.

AMPR instrument was flown on the NASA ER-2 aircraft over Texas from April 9 through May 6, 1998 for the TEFLUN-A experiment and over Florida from August5 through September 27, 1998 for the TEFLUN-B & CAMEX-3 field campaigns.

AMPR is a cross-track scanning total power microwave radiometer with four channels centered at 10.7, 19.35, 37.1 and 85.5 GHz. The AMPR measurements were made under the direction of the NASA/GSFC scientists Ms. Robbie Hood (Principal Investigator) and Mr.Frank LaFontaine(co-investigator). The calibrated brightness temperatures are used for the validation of TRMM TMI brightness temperatures and rain algorithms.

The TEFLUN-A data sets are archived at the Goddard Data and Information Services Center (DISC).

Sponsor

The distribution of these data sets is funded by NASA's Earth Science Enterprise. The data are not copyrighted; however, we request that when you publish data or results using these data, please acknowledge as follows:

The authors wish to thank Ms. Robbie Hood and Mr.Frank LaFontaine (NASA/Marshall Space Flight Center) for the production of this AMPR data set. They also thank the Data and Information Services Center (Code 610.2) at the Goddard Space Flight Center, Greenbelt, MD, 20771, for making it available to the scientific community. Goddard's contribution to the distribution and archive of this data set was sponsored by NASA's Earth Science Enterprise.

The Data

Characteristics

The data is very preliminary, before using this data in your publication, please contact the Principal Investigator Ms.Robbie Hood .

The Files

TEFLUN-A AMPR data

Flight Date (UTC)	Start-stop time UTC	# 15 minute Images
5 Apr 98	1600 - 1730	6
9 Apr 98	1615 - 2000	15
15 Apr 98	0100 - 0245	7
18 Apr 98	1700 - 2045	15
21 Apr 98	0415 - 0800	15
23 Apr 98	0315 - 0500	7
27 Apr 98	0000 - 0315	13
1 May 98	0030 - 0415	15
4 May 98	2115 - 0300	13
6 May 98	1845 - 2315	18

Files Format

Data are available in binary format and each file represents one flight. The native (binary) file type is labeled "Extended Package" [EP] and filenames have this abbreviation within them. The information file associated with the data files named READ_ME_AMPR_archive.txt is provided in the ampr directory at the FTP site.

File Naming Convention

The file naming convention for AMPR data (adopted by GHRC)is:

ampr_CAMEX-3_98124_R8ntb_EPc27May99.sys

where:

ampr = instrument name

CAMEX-3 = experiment acronym

98124 = launch date (yyddd)

R8ntb = High precision navigated brightness temperatures

EP = Extended Package data set type

c06Oct98 = creation date

.sys = binary data (.sys = SGI system format option)

The EP (extended package) record structure is as shown in the following table. A value of -32768 is a flag indicating that the data are not useable and a value of -22222 is a flag which indicates the data calculation(s) were not executable.
 

Data Format

Sequence	Format	Vals	Data type	Units
1	Integer*2	1	Scan number
2	Integer*2	1	Year	UTC
3	Integer*2	1	Day-of-year	UTC
4	Integer*2	1	Hour	UTC
5	Integer*2	1	Minute	UTC
6	Integer*2	1	Second	UTC
7	Integer*2	1	GPS validity code	1=good
8	real*8	1	GPS Altitude	meters
9	real*8	1	GPS Latitude	degrees
10	real*8	1	GPS Longitude	degrees
11	real*8	1	Heading (0, 360=North, clockwise)	degrees
12	real*8	1	Pitch (+ is nose up)	degrees
13	real*8	1	Roll (+ is right wing down)	degrees
14	real*8	1	Ground Speed	m/s
15	real*8	1	Air Speed	m/s
16	real*8	1	Barometric Altitude	meters
17	real*8	1	INS Latitude	degrees
18	real*8	1	INS Longitude	degrees
19-22	real*8	4	RMS noise (10, 19, 37, 85 GHz)	Kelvin
23-72	real*8	50	Pixel TB's at 10.7 GHz	Kelvin
73-122	real*8	50	Pixel TB's at 19.35 GHz	Kelvin
123-172	real*8	50	Pixel TB's at 37.1 GHz	Kelvin
173-222	real*8	50	Pixel TB's at 85.5 GHz	Kelvin
223-272	real*8	50	Pixel Latitude	degrees
273-322	real*8	50	Pixel Longitudes	degrees

Companion Software

A FORTRAN read program read_ampr_EPdata.f is provided by the data producers as an example of how to read a binary AMPR data file on a UNIX system. Source code for this FORTRAN program is available in the document directory in the anonymous FTP area.

The source code of the FORTRAN program (read_ampr_EPdata.f) (which includes an example for use in extracting AMPR data from the EP binary file) is also given below.

=============== beginning of source code ===========

program read_ampr_EPdata
c
c Data reader for the *R8ntb_EP* type of public AMPR data.  
c Frank LaFontaine (Raytheon ITSS)   Sep 98 --- New.
c
      implicit   real*8 (a-h,o-z),
integer*4 (i-n)
      parameter  maxrec=10000
      logical    exist, done
      character  file_format*12,
file_name*80
      integer*4  iscan(maxrec),
itime(5,maxrec), igps(maxrec)
      real*8    
rmsN(4,maxrec), er2nav(11,maxrec), tbs10(50,maxrec),
               
tbs19(50,maxrec), tbs37(50,maxrec), tbs85(50,maxrec),
               
xlat(50,maxrec), xlon(50,maxrec)

c Get command input.
      if (iargc() .eq. 2) then
         call getarg (1,
file_format)
         call getarg (2,
file_name)
      else
         print*
         print*,' 
Usage:  read_ampr_EPdata  file_format  file_name'
         print*
        
print*,'       file_format: 
formatted, system, '//
                                   
'unformatted, or binary'
         print*
        
print*,'      
file_name:    enter the AMPR "EP" file name'
         print*
         stop
      endif

c Check for input file existance.
      inquire (file=file_name, exist=exist)
      if (.not. exist) then
         print*
         print*,'  
Invalid input file name: ',file_name
         print*
         stop ' '
      endif

c Open and read all the data from the file.
      open (11, file=file_name,
form=file_format, readonly)

      i = 0
      done = .false.
      do while (.not. done)
         i = i + 1
         if (file_format .eq.
'formatted') then
           
read (11, 1100, err=101, end=101)  
                    
iscan(i), (itime(j,i), j=1,5), igps(i),
                    
(er2nav(j,i), j=1,11), (rmsN(j,i), j=1,4),
                    
(tbs10(j,i), j=1,50), (tbs19(j,i), j=1,50),
                    
(tbs37(j,i), j=1,50), (tbs85(j,i), j=1,50),
                    
(xlat(j,i), j=1,50), (xlon(j,i), j=1,50)
         else
           
read (11, err=101, end=101)
                    
iscan(i), (itime(j,i), j=1,5), igps(i),
                    
(er2nav(j,i), j=1,11), (rmsN(j,i), j=1,4),
                    
(tbs10(j,i), j=1,50), (tbs19(j,i), j=1,50),
                    
(tbs37(j,i), j=1,50), (tbs85(j,i), j=1,50),
                    
(xlat(j,i), j=1,50), (xlon(j,i), j=1,50)
         endif
      enddo

 1100 format ( 6i8, i8,f10.2,2f14.6,5f12.4,f10.2,2f14.6,
             
4f12.4, 200f12.4, 100f14.6)
  101 continue
      nscans = i - 1
      close (11)
      print*
      print*,'All data read...'
      print*

c FOR EXAMPLE:
c Print to the screen the scan#, date, time, and element 25 of
each 
c frequency, with latitude and longitude at that point.  Pause
every 100 scans.
      do i= 1, nscans
         write (6, 6001) 
iscan(i), (itime(j,i), j=1,5),
                        
tbs10(25,i), tbs19(25,i), tbs37(25,i),
                        
tbs85(25,i), xlat(25,i), xlon(25,i)
         if (mod(i,100) .eq.
0)  pause
      enddo
 6001 format ('Scan: ',i4,2x,'Date: ',i4,i3,2x,
            
'Time(UTC): ',i2,':',i2,':',i2,3x,'Tb10: ',f6.2,2x,
            
'Tb19: ',f6.2,2x,'Tb37: ',f6.2,2x,'Tb85: ',f6.2,3x,
            
'Lat: ',f9.5,2x,'Lon: ',f10.5)
      print*
      print*,'    
*******  read_ampr_EPdata is done  *******'
      stop
      end

=================== End of source code==========
 
 

Data Access and Contacts

Data Access

FTP Site

The TEFLUN aircraft data resides on DISC anonymous FTP. You may access the files from this document,

AMPR Calibrated Brightness Temperatures(Binary files)

AMPR Browse Images

or directly via FTP at

ftp disc2.nascom.nasa.gov

login: anonymous

password: < your internet address >

cd data/TEFLUNA/aircraft/nasa_er2/ampr

Points of Contact

For Information about TEFLUN data at Goddard DISC, please contact

Hydrology Data Support Team
NASA Goddard Space Flight Center
Greenbelt, MD 20771
email: hydrology@disc.gsfc.nasa.gov

Technical Inquiries about this Data should be addressed to:

Principal Investigator:
Ms. Robbie Hood
Global Hydrology and Climate Center
977 Explorer Blvd.
Huntsville, Alabama 35806
Phone: 256-922-5959
Fax: 256-922-5723
E-mail: robbie.hood@msfc.nasa.gov

or

Co-investigator:

Mr. Frank LaFontaine
Global Hydrology and Climate Center
977 Explorer Blvd.
Huntsville, Alabama 35806
Phone: 256-922-5796
Fax: 256-922-5723
E-mail: frank.lafontaine@msfc.nasa.gov