aces.holography.grid_holography

Grid holography data

Module Contents

Functions

get_antenna_locations(location_file)	Will parse a file the describes the location of the ASKAP antennas. This partticular files
select_obs_radec(sbid)	Read pointing data extracted from ms tables, locate one point per grid point
dipa_to_lm(d, pa)	Given a distance, position_angle offset relative to a sky position,
get_true_azel(ra, dec, tim, ant_loc)	Given a sequence of celestial coordinates (ra, dec) and times, and the observer location,
get_obs_grid(az, el, refant)	param az:
grid_corr(data, mapset, refant, ant_loc)	Regrids the sampled data onto the intended grid on the sky.
raw_to_grid(raw_file_name, beam, refant, ant_loc)	Reads holography data in hdf5 MapSet format. Performs operations on the
main(sbid, beam[, holo_dir, refant])	Main script
cli()

Attributes

log

aces.holography.grid_holography.log

aces.holography.grid_holography.get_antenna_locations(location_file)

Will parse a file the describes the location of the ASKAP antennas. This partticular files is newline delimited, with a separate line describing their wgs84 and itrf positions. This file returns their wgs84 position as an antenna ordered list of XYZ positions.

Parameters:

location_file – Path to ‘antenna_positions_itrf.txt’ file (packaged with aces.holography submodule. )

Returns:

list of XYZ antenna positions, ordered by antenna number

aces.holography.grid_holography.select_obs_radec(sbid)

Read pointing data extracted from ms tables, locate one point per grid point and return az,el for ref ant (az0, el0) az,el for another ant (aza,ela), RA,Dec for each, and the time (UTC).

Parameters:

sbid – The sbid of the observation being processed

Returns:

The RA and Dec positions the beams were pointed towards, and the times int UTC they were there

aces.holography.grid_holography.dipa_to_lm(d, pa)

Given a distance, position_angle offset relative to a sky position, return the equivalent (l,m)

Parameters:

d – distance

:param pa:position_angle :return: rectangular offset - orthographic proejction

aces.holography.grid_holography.get_true_azel(ra, dec, tim, ant_loc)

Given a sequence of celestial coordinates (ra, dec) and times, and the observer location, calculate the topcentric coordinates of each. Coordinates should be for J2000. Times should be UTC. The routine uses astropy procedures. :param ra: Sequence of right ascensions in radians :param dec: Sequence of declinations in radians :param tim: Sequence of times in seconds of MJD :param ant_loc: observer’s location, geocentric in metres :return:

aces.holography.grid_holography.get_obs_grid(az, el, refant)

Parameters:

• az –

• el –

Returns:

aces.holography.grid_holography.grid_corr(data, mapset, refant, ant_loc)

Regrids the sampled data onto the intended grid on the sky. The input data should be in its native form (not subjected to sky_transform)

Parameters:

• data – Holography complex voltages in mapset formatted array

• mapset – mapset object holding this dataset

• refant – Reference antenna; if None, retrieved from SB database

:param ant_loc Antenna locations :return: regridded data

aces.holography.grid_holography.raw_to_grid(raw_file_name, beam, refant, ant_loc)

Reads holography data in hdf5 MapSet format. Performs operations on the data hyper-cube: * interpolates data onto regular grid * saves gridded data for the given beam in hdf5 MapSet format

Parameters:

• raw_file_name – (str) Name of hdf5 holography data file

• beam – (int) Beam number to process (0-based)

• refant – (int) Antenna number to use for grid reference (0-based)

:param ant_loc Antenna locations

aces.holography.grid_holography.main(sbid, beam, holo_dir='.', refant=None)

Main script

Parameters:

• sbid (int) – SBID

• beam (int) – beam number

• holo_dir (str) – directory holding holograophy data

• refant – (int) Antenna number to use for grid reference (0-based)

aces.holography.grid_holography.cli()