Pulsar tool¶

arts_tools.pulsars.find_pulsars¶

arts_tools.pulsars.find_pulsars.get_half_power_width(freq)¶

Calculate compound beam half-power width, assuming linear scaling with frequency

Parameters:: freq (Quantity) – Frequency
Returns:: half-power width (Quantity)

arts_tools.pulsars.find_pulsars.main()¶

arts_tools.pulsars.find_pulsars.make_plot(cb_coord, psr_coord, hpbw)¶

Create a plot of the CB pattern with pulsar locations

Parameters:

cb_coord (list) – List of SkyCoord objects with CB pointings
psr_coord (list) – List of (name, SkyCoord) tuples with pulsar names and positions
hpbw (Quantity) – half-power beam width of the CBs

ALTA downloads¶

arts_tools.archive.download_from_alta¶

arts_tools.archive.download_from_alta.get_file_paths(release, taskid, cbs, tabs)¶

Construct path to files in ALTA

Parameters:

release (str) – Data release (SVC or internal)
taskid (str) – Observation taskid
cbs (iterator) – compound beams to download
tabs (iterator) – tied-array beams to download of each compound beam

Returns:

list of file paths

arts_tools.archive.download_from_alta.main()¶

arts_tools.archive.download_helpers¶

class arts_tools.archive.download_helpers.DownloadProgressBar(*_, **__)¶

Bases: tqdm

A progress bar for downloads using tqdm based on https://stackoverflow.com/questions/15644964/python-progress-bar-and-downloads

update_to(nbyte=1, blocksize=1, totalsize=None)¶

arts_tools.archive.download_helpers.download_irods(path, output_folder=None, overwrite=False)¶

Download file from ALTA using iRODS

Parameters:

path – Path to file on iRODS server
output_folder (str) – Output folder (Default: current directory)
overwrite (bool) – Overwrite output file if it already exists

arts_tools.archive.download_helpers.download_url(url, output_folder=None, overwrite=False, verbose=False)¶

Download file from given url

Parameters:

url – URL to download file from
output_folder (str) – Output folder (Default: current directory)
overwrite (bool) – Overwrite output file if it already exists
verbose (bool) – Print download progress

arts_tools.archive.download_helpers.format_bytes(nbytes)¶

Format a number in bytes with a prefix

Parameters:: nbytes (int) – number of bytes (>0)
Returns:: number of MB/GB etc (float), unit (MB/GB etc) (str)

arts_tools.archive.download_helpers.print_progress(nblock, nbyte_per_block, nbyte_total, step=5)¶

Print download progress of urllib.request.urlretrieve command

Parameters:

nblock –
nbyte_per_block –
total_bytes –
step (int) – progress is only printed if the percentage is a multiple of step

FITS file handling¶

arts_tools.fits.reader¶

arts_tools.fits.reader.read_header(fname, hdu=None)¶

Read fits header

Parameters:

fname (str) – Path to fits file
hdu (int/str) – HDU to read header from (default: all)

Returns:

header (astropy.io.fits.header.Header) or list of headers if hdu is not specified

arts_tools.fits.reader.read_parameterset(fname)¶

Read observation parameterset from fits file

Parameters:: fname (str) – Path to fits file
Returns:: parameterset (dict)

arts_tools.fits.fix_file_from_before_20200408¶

arts_tools.fits.fix_file_from_before_20200408.ALIGN = 2880¶: fits file alignment block size in bytes

arts_tools.fits.fix_file_from_before_20200408.NAXIS1 = 30220¶: NAXIS1 in original data

arts_tools.fits.fix_file_from_before_20200408.NCHAN = 384¶: Number of frequency channels in original data

arts_tools.fits.fix_file_from_before_20200408.NSAMP = 500¶: Number of time samples per subint in original data

arts_tools.fits.fix_file_from_before_20200408.TSUBINT = 1.024¶: Number of seconds per subint in original data

arts_tools.fits.fix_file_from_before_20200408.fix_data(data, naxis2)¶

Fix the data: Swap time and frequency axis, reverse frequency ordering

Parameters:

data (bytes) – raw data, without padding
naxis2 (int) – NAXIS2 value

Returns:

fixed data (bytes)

arts_tools.fits.fix_file_from_before_20200408.fix_header(header, naxis2, force=False)¶

Fix the header: replace NAXIS2 = 0 by correct value and replaces data column bits by bytes

Parameters:

header (str) – full header, including padding, as single string
naxis2 (int) – new NAXIS2 value
force (bool) – Overwrite NAXIS2 even if original value was not zero

Returns:

fixed header (bytes)

arts_tools.fits.fix_file_from_before_20200408.get_data(fname, hdr_size)¶

Read raw data

Parameters:

fname (str) – Path to fits file
hdr_size (int) – Header size in bytes, aligned to fits block

Returns:

raw data (bytes), padding (bytes), derived naxis2 (int)

arts_tools.fits.fix_file_from_before_20200408.get_header(fname)¶

Read header from fits file, assuming there are 2 HDUs

Parameters:: fname (str) – Path to fits file
Returns:: raw header (bytes), header size in bytes (int)

arts_tools.fits.fix_file_from_before_20200408.main()¶

arts_tools.fits.fix_file_from_before_20200408.write_file(fname, *args)¶

Write output file

Parameters:

fname – path to output file
args – byte array to write to file, usually header, data, and padding

IQUV PSRDADA to PSRFITS conversion¶

arts_tools.iquv.psrdada_to_fits¶

General tools¶

arts_tools.tools.altaz_to_hadec(alt, az, lat=<Latitude 52.91532992 deg>)¶

Convert Alt, Az to HA, Dec

Parameters:

alt – altitude with unit
az – azimuth with unit
lat – Latitude with unit (default: WSRT)

Returns:

hour angle, declination

arts_tools.tools.cb_index_to_pointing(cb, pointing_ra, pointing_dec)¶

Get pointing of given CB based on telescope pointing

Parameters:

cb (int/list) – CB index
pointing_ra (Quantity) – Pointing right ascension
pointing_dec (Quantity) – Pointing Declination

Returns:

(RA, Dec) tuple of CB pointing, with unit

arts_tools.tools.coord_to_offset(ra0, dec0, ra1, dec1)¶

Convert point (ra1, dec1) to projected offset from reference (ra0, dec0)

Parameters:

ra0 – Reference RA or Az
dec0 – Reference Dec or Alt
ra1 – Target RA or Az
dec1 – Target Dec or Alt

Returns:

(theta, phi) offset theta is offset in RA or Az phi is offset in Dec or Alt

arts_tools.tools.hadec_to_altaz(ha, dec, lat=<Latitude 52.91532992 deg>)¶

Convert HA, Dec to Alt, Az

Parameters:

ha – hour angle with unit
dec – declination with unit
lat – Latitude with unit (default: WSRT)

Returns:

altitude, azimuth

arts_tools.tools.hadec_to_par(ha, dec, lat=<Latitude 52.91532992 deg>)¶

Convert HA, Dec to parallactic angle

Parameters:

ha – hour angle with unit
dec – declination with unit
lat – Latitude with unit (default: WSRT)

Returns:

parallactic angle

arts_tools.tools.hadec_to_proj(ha, dec, lat=<Latitude 52.91532992 deg>)¶

Convert HA, Dec to E-W baseline projection angle

Parameters:

ha – hour angle with unit
dec – declination with unit
lat – Latitude with unit (default: WSRT)

Returns:

projection angle

arts_tools.tools.hadec_to_radec(ha, dec, t, lon=<Latitude 52.91532992 deg>)¶

Convert apparent HA, Dec to J2000 RA, Dec

Parameters:

ha – hour angle with unit
dec – declination with unit
t – UT time (string or astropy.time.Time)
lon – Longitude with unit (default: WSRT)

Returns:

SkyCoord object of J2000 coordinates

arts_tools.tools.limit(val, minval=-1, maxval=1)¶

Where val > maxval, replace by maxval

Where val < minval, replace by minval

Parameters:

val – input value
minval – minimum value
maxval – maximum value

Returns:

limited value

arts_tools.tools.offset_to_coord(ra0, dec0, theta, phi)¶

Convert a projected offset (theta, phi) to coordinate with reference (ra0, dec0)

Parameters:

ra0 – Reference RA or Az
dec0 – Reference Dec or Alt
theta – RA or Az offset
phi – Dec or Alt offset

Returns:

(Ra, Dec) or (Az, Alt) of offset point

arts_tools.tools.radec_to_hadec(ra, dec, t, lon=<Longitude 6.60894465 deg>)¶

Convert J2000 RA, Dec to apparent HA, Dec

Parameters:

ra – right ascension with unit
dec – declination with unit
t – UT time (string or astropy.time.Time)
lon – Longitude with unit (default: WSRT)

Returns:

HA, Dec with unit