1. INTRODUCTION

Sar Raw Data

Acronym: SAR.RAW

Decommutated raw SAR echos data suitable for input to a processor.

The product is stored on two CCTs.

1) General CCTs structure

CCT1 contains the following three files :

Volume Directory File Leader File Data Set File

2) Files description

a) Volume Directory File:

     volume descriptor record           360 bytes (mandatory)

     leader file pointer record         360 bytes (mandatory)

     data set file pointer record       360 bytes (mandatory) 

     text record                        360 bytes (mandatory)

b) Leader File:

    file descriptor record                       720 bytes (mandatory)            

     data set summary record                    1886 bytes (mandatory)

     platform position data record              .... bytes (optional)

     radiometric compensation record            .... bytes (optional)

     radar parameter update data record         .... bytes (optional)

     facility related data record              12288 bytes (mandatory)  
     general type

     facility related data record              12288 bytes (optional)  
     pcs quality type

c) Data Set File:

     file descriptor record                    11644 bytes (mandatory)         

     13600 signal data record                  11644 bytes (mandatory)

CCT2 contains the following three files :

Volume Directory File Data Set File Null Volume File

d) Volume Directory File (update of CCT1):

     volume descriptor record              360 bytes (mandatory)

     leader file pointer record            360 bytes (mandatory)

     data set file pointer record          360 bytes (mandatory) 

     text record                           360 bytes (mandatory)

e) Data Set File:

     ..... signal data records             11644 bytes (mandatory)

f) Null Volume File:

     volume descriptor record                360 bytes (mandatory)

Notation conventions :

$ - the use of the "$"' (dollar sign) in the documentation denotes a requirement for the blank character (ie. the ASCII or EBCDIC space character).

(n) - this expression is used to denote the contents of an integer binary field which will vary depending on the product type or data origin and will have to be supplied on the CCT by the facility generating the CCT.

<.....> - this expression is used to denote the contents of an alphanumeric field, which will vary depending on the product type or data origin and will have to be supplied on the CCT by the facility generating the CCT.

<$...$> - this expression is used to denote a blank field.

File Class                           Class Code         Data Type

"8$BIT$ASCII$0NLY$$$$$$$$$$$$"      "ASCO"              ASCII only data
"EBCDIC$0NLY$$$$$$$$$$$$$$$$$"      "EBCO"              EBCDIC only
"BCD$0NLY$$$$$$$$$$$$$$$$$$$$"      "BCDO"              BCD only
"BINARY$0NLY$$$$$$$$$$$$$$$$$"      "BINO"              binary only data
"MIXED$BINARY$AND$ASCII$$$$$$"      "MBAA"              binary & ASCII
"MIXED$BINARY$AND$EBCDIC$$$$$"      "MBAE"              binary & EBCDIC
"MIXED$BINARY$AND$BCD$$$$$$$$"      "MBAB"              binary & BCD
"UNDEFINED,$ETC.$$$$$$$$$$$$$"      "UNDF"              undefined
"C0MPLEX$$$$$$$$$$$$$$$$$$$$$"      "COMP"              complex
"REAL$$$$$$$$$$$$$$$$$$$$$$$$"      "REAL"              floating point


Data Interpretation                 Format             Length

"INTEGER*1$$$$$$$$$$$$$$$$$$$"      "I*1$"             (1 byte wide)
"INTEGER*2$$$$$$$$$$$$$$$$$$$"      "I*2$"             (2 byte wide)
"INTEGER*4$$$$$$$$$$$$$$$$$$$"      "I*4$"             (4 byte wide)
- one, two and four byte two"s complement integer representation

"SIGNED$INTEGER*1$$$$$$$$$$$$"      "IS1$"             (1 byte wide)
"SIGNED$INTEGER*2$$$$$$$$$$$$"      "IS2$"             (2 byte wide)
"SIGNED$INTEGER*4$$$$$$$$$$$$"      "IS4$"             (4 byte wide)
- one, two and four byte signed integer with the  most significant
  bit used to denote sign

"UNSIGNED$INTEGER*1$$$$$$$$$$"      "IU1$"             (1 byte wide)
"UNSIGNED$INTEGER*2$$$$$$$$$$"      "IU2$"             (2 byte wide)
"UNSIGNED$INTEGER*4$$$$$$$$$$"      "IU4$"             (4 byte wide)
- one, two and four byte un    -signed integer with the  most significant
  bit used as part of the pixel value, the pixel is always positive.

"REAL*2$$$$$$$$$$$$$$$$$$$$$$"      "R*2$"             (2 byte wide)
"REAL*4$$$$$$$$$$$$$$$$$$$$$$"      "R*4$"             (4 byte wide)
"REAL*8$$$$$$$$$$$$$$$$$$$$$$"      "R*8$"             (8 byte wide)
- two, four and eight byte two's complement floating point representation
  with the exponent denoted in two's complement binary.(note that the REAL*8
  representation is the same as double precision.)


Data Interpretation                 Format             Length


"REAL*2$HEXADECIMAL$$$$$$$$$$"      "R*2H"             (2 byte wide)
"REAL*4$HEXADECIMAL$$$$$$$$$$"      "R*4H"             (4 byte wide)
"REAL*8$HEXADECIMAL$$$$$$$$$$"      "R*8H"             (8 byte wide)
- two, four eight byte hexadecimal floating point representation with the 
  exponent denoted as a hexadecimal exponent. (note that the REAL*8.
  representation is the same as double precision.)

"C0MPLEX*4$$$$$$$$$$$$$$$$$$$"      "C*4$"             (4 byte wide)
"C0MPLEX*8$$$$$$$$$$$$$$$$$$$"      "C*8$"             (8 byte wide)
- four byte field with the first half (two bytes) containing the two"s
  complement floating point representation value of the real component and
  the second half containing the imaginary component.Similarly for the eight
  byte type, with each half of the field containing the real and imaginary
  pairs.
 
"C0MPLEX$INTEGER*2$$$$$$$$$$$"      "CI*2"             (2 byte wide)
"C0MPLEX$INTEGER*4$$$$$$$$$$$"      "CI*4"             (4 byte wide)
"C0MPLEX$INTEGER*8$$$$$$$$$$$~      "CI*8"             (8 byte wide)
- similar to the complex floating point representation above except that
  each component is stored as a two"s complement integer.

"C0MPLEX$SIGNED$INTEGER*2$$$$"      "CIS2"             (2 byte wide)
"C0MPLEX$SIGNED$INTEGER*4$$$$"      "CIS4"             (4 byte wide)
"C0MPLEX$SIGNED$INTEGER*8$$$$"      "CIS8"             (8 byte wide)
- similar to the complex floating point representation above except that
  each component is stored as a signed integer.

"C0MPLEX*4$HEXADECIMAL$$$$$$$"      "C*4H"             (4 byte wide)
"C0MPLEX*8$HEXADECIMAL$$$$$$$"      "C*8H"             (8 byte wide)
- same as the floating point complex notation above except that the
  representation follows the hexadecimal conventions.


Records in products                                      CEOS   Codes

Volume Directory File

- VOLUME DESCRIPTOR RECORD                              (192,192,18,18)
- FILE POINTER RECORD                                   (219,192,18,18)
- TEXT RECORD                                           (18,63,18,18)

Leader File

- FILE DESCRIPTOR RECORD                                (63,192,18,18)
- DATA SET SUMMARY RECORD                               (10, 10,31,20)
- PLATFORM POSITION DATA RECORD                         (10, 30,31,20)
- RADIOMETRIC COMPENSATION RECORD                       (10, 51,31,20)
- RADAR PARAMETER DATA UPDATE RECORD                    (10,100,31,20)
- FACILITY RELATED DATA RECORD GENERAL TYPE             (10,200,31,50)
- FACILITY RELATED DATA RECORD PCS QUALITY TYPE         (10,200,31,50)

SAR Data File

- FILE DESCRIPTOR RECORD                                (63,192,18,18)
- RAW SIGNAL DATA RECORD                                 (50,10,31,20)

Null Volume

- NULL VOLUME DESCRIPTOR RECORD                         (192,192,63,18)

Note:

Fields not provided are treated as follows:( for a case of a field 8 bytes long)

   Field type           Format           Filler

   alphanumeric           A8             8 blanks

   numeric integer        Iw             -9999999

   numeric floating point F8.2           -9999.99

   numeric exponential    E8.2           -9999.99E-99