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If you are using raw ASTERIX formatted data, you can skip this format since it is just related to a custom extension to ASTERIX. If your ASTERIX data is in a file with ".astfin" extension, this document explains the format of the data in the file. |
The ASTERIX Final format is a simple extension of the ASTERIX standard.
Regular ASTERIX blocks are wrapped in an ASTERIX Final envelope. Each envelope has the following structure:
HEADER NormalAsterixBlock1 NormalAsterixBlock2 ... FOOTER
The ASTERIX Final envelopes are concatenated in a file, one after the other.
The header of eight bytes is composed like this:
|
byte 0 |
length (msb) |
|
byte 1 |
length (lsb) |
|
byte 2 |
board number |
|
byte 3 |
line number |
|
byte 4 |
recording day |
|
byte 5 |
time (msb) |
|
byte 6 |
time |
|
byte 7 |
time (lsb) |
The length is a two-byte integer, starting with the most significant byte. It includes the length of the header and the footer itself. The board number, line number and recording day field are generally not used and set to 0. The time is expressed in hundredths of a second past midnight, as a three-bytes integer, starting with the most significant byte.
The footer is four times the byte 0xa5 (decimal 165).