Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

For the 'standard' MWA system, with 128 dual polarisation tiles, all being recorded, the file size is 5269098496 5275652096 bytes (~5GB)


The file begins with a 4096 byte ASCII header containing a subset of metadata for the observation.

There is then a 'delay metadata' block, used for fringe-tracking, of size:  numTiles * 2 * 102400 128000 bytes.  For the standard 128T array, this is 26214400 bytes32768000 bytes.

There are then 200 160 independent 'voltage data' blocks, each the same size as the delay metadata block.  That is numTiles * 2 * 102400 128000 bytes.


The total file size of a 128-Tile observation file is therefore 4096 + 201 161 * 26214400 or  5269098496 32768000 or 5275652096 bytes.


Each 'voltage data' block contains 40ms 50ms of raw voltage data for each tile.

...

Antenna 0 polarisation X  (5164,200 000 consecutive samples)

Antenna 0 polarisation Y (5164,200 000 consecutive samples)

Antenna 1 polarisation X (5164,200 000 consecutive samples)

Antenna 1 polarisation Y (5164,200 000 consecutive samples)

Antenna 2 polarisation X (5164,200 000 consecutive samples)

Antenna 2 polarisation Y (5164,200 000 consecutive samples)

… through to the final antenna in this observation.  Assuming n tiles, that would be:

Antenna (n-1) polarisation X (5164,200 000 consecutive samples)

Antenna (n-1) polarisation Y  (5164,200 000 consecutive samples)


Each sample is two Bytes.  One byte 'real' followed by one byte 'imaginary'. The values are stored as 'signed chars' in standard 'twos complement'.  5164,200 000 samples are therefore 102400 128000 bytes.  Each Tile is assumed to have two polarisations.

...