pycrtools.tasks.imager

CoordinateGrid([obstime, ut1_utc, L, phi])	Coordinate grid for images.
Imager([ws, parfile])	Creates an image using beamforming for each pixel.
Task([ws, parfile])	Base class from which all tasks should be derived.
savefits(filename, array[, overwrite])	Save image as standard FITS file.

Imager

Module author: Pim Schellart <P.Schellart@astro.ru.nl>

Code author: J.Emilio Enriquez <e.enriquez@astro.ru.nl>

class pycrtools.tasks.imager.Imager(ws=None, parfile=None, **kwargs)

Creates an image using beamforming for each pixel.

A grid of pixels is formed based on standards FITS coordinate descriptions. Then calculates the total power for a given pixel (pointing) by beamforming and adds the selected antennas/time steps/frequency range.

Note

It does not calculate the visibities from the multiple baselines.

See also

Representations of celestial coordinates in FITS (http://adsabs.harvard.edu/abs/2002A%26A...395.1077C)

Input parameters

CDELT1 [default value: 2.56666660309 ]

CDELT2 [default value: 2.56666660309 ]

CDELT3

CDELT4

CRPIX1

CRPIX2

CRPIX3 [default value: 0.0 ]

CRPIX4 [default value: 0.0 ]

CRVAL1 [default value: 180.0 ]

CRVAL2 [default value: 90.0 ]

CRVAL3 [default value: 0.0 ]

CRVAL4 [default value: 0.0 ]

CTYPE1 [default value: “ALON-STG” ]

CTYPE2 [default value: “ALAT-STG” ]

CTYPE3 [default value: “FREQ” ]

CTYPE4 [default value: “TIME” ]

CUNIT1 [default value: “deg” ]

CUNIT2 [default value: “deg” ]

CUNIT3 [default value: “Hz” ]

CUNIT4 [default value: “s” ]

FREQMAX [default value: None ]

Maximum frequency to use.

FREQMIN [default value: None ]

Minimum frequency to use.

LATPOLE [default value: 90.0 ]

LONPOLE [default value: 0.0 ]

NAXIS [default value: 4 ]

NAXIS1 [default value: 90 ]

NAXIS2 [default value: 90 ]

NAXIS3 [default value: 1 ]

NAXIS4 [default value: 1 ]

OBSLAT [default value: 0.923543111634 ]

Observer latitude in radians

OBSLON [default value: 0.11990128415 ]

Observer longitude in radians

OBSTIME

Observation time in sec.

PC001001 [default value: 1.0 ]

PC001002 [default value: 0.0 ]

PC002001 [default value: 0.0 ]

PC002002 [default value: 1.0 ]

data [default value: None ]

image [default value: None ]

intgrfreq [default value: False ]

Output frequency integrated image.

inversefft [default value: False ]

Used for a time series image.

nblocks [default value: 1 ]

Number of blocks.

ntimesteps

Number of time steps.

output [default value: “out.fits” ]

Output filename.

phase_calibrate [default value: False ]

Use DIPOLE_CALIBRATION_DELAY to phase calibrate FFT data before imaging.

rfi_remove [default value: None ]

List of frequency indices to remove.

startblock [default value: 0 ]

Block start number.

init()

Initialize imager.

run()

Run the imager.

pycrtools.tasks.imager.savefits(filename, array, overwrite=True, **kwargs)

Save image as standard FITS file.