shimmerr package¶

Submodules¶

shimmerr.array module¶

class shimmerr.array.Antenna(position, gain=1 + 0j)¶

Bases: object

A class that represents the lowest level elements in the array.

Attributes¶

p: list: Contains the 3D position of the antenna in ECEF (Earth-Centered Earth-Fixed) coordinates
p_ENU: list: Contains the 3D position of the antenna in ENU (East-North-Up) coordinates
g: complex: Complex gain of the element

__init__(position, gain=1 + 0j)¶

Parameters¶

positionlist: Contains the 3D position of the antenna in ETRS coordinates
gaincomplex, optional: Complex gain of the element, by default 1

calculate_response(directions, frequency, mode='omnidirectional')¶

Calculates the element response in directions.

Parameters¶

directionsndarray: 3xM array of unit length vectors that decribe the directions in ENU coordinates
frequencyfloat: Frequency of the measurement
modestr, optional: sets the beam shape, by default “omnidirectional” (no directivity).

Returns¶

ndarray: M length response

update_antenna(new_gain=None)¶: Updates antenna gain

class shimmerr.array.Station(positions, pointing_ra=None, pointing_dec=None, gain=1 + 0j)¶

Bases: object

A class that represents the full station.

Attributes¶

p: list: Contains the 3D position of the station in ECEF (Earth-Centered Earth-Fixed) coordinates
p_array: list: Contains the 3D position of the station in ENU (East-North-Up) coordinates of a specified reference stataion
g: complex: Complex gain of the element
d: ndarray: Complex pointing of the station (in Ra, Dec)
tracking: bool: If set, the telescope is in tracking mode (pointed to a specific point), if False, the telescope is in drift-scan mode

ENU_rotation_matrix()¶: Calculates the 3x3 matrix that transforms the coordinates from ECEF (Earth-Centered Earth-Fixed) to ENU (East-North-Up)

__init__(positions, pointing_ra=None, pointing_dec=None, gain=1 + 0j)¶

Parameters¶

positionslist: Contains the 3D position of the elements (tiles) in ECEF (Earth-Centered Earth-Fixed) coordinates
pointing_rafloat, optional: Right ascension of the phase center in deg, default is None
pointing_decfloat, optional: Declination of the phase center in deg, default is None
gaincomplex, optional: Complex gain of the tile (shared by all elements), by default 1

add_random_gain_drift(sigma_tile, sigma_antenna, seed=None)¶

Add complex Gaussian zero mean noise to the gains.

Parameters¶

sigma_tilefloat: Standard deviation of the noise added on a tile level
sigma_antennafloat: Standard deviation of the noise added on an antenna level
seedNone or int, optional: Seed of the random generator. Set by an integer for reproducability, by default None

break_elements(mode='maximum', number=0, seed=None)¶

Breaks elements within the tiles of the array (by setting their gains to 0). Set the seed for reproducability, but be aware that a different seed should be used for different stations to guarantee randomness.

Parameters¶

modestr, optional: Sets the way in which elements are broken, by default “maximum” maximum: Uniformly breaks elements up to a maximum number. If higher than the number of elements per tile, the full tile will be flagged more often (numbers between #elements and max are shifted to max) number: Breaks the specified number of elements. If higher than the number of antennas in a tile, all antennas are broken. Rounds to nearest number of elements per tile (so 10% of 16 elements = 1.6 elements –> 2 elements flagged in every tile) percentage: Same as number but with a percentage. typical: Breaks elements according to a normal(number, number) distribution, such that on average <number> elements are broken. typical_percentage: the same as above but with a percentage.
numberint, optional: Number that controls how many elements are broken (so maximum, percentage, etc.), by default 0
seedint, optional: seed for the random number generator that controls how many and which elements are broken, by default None (initialize randomly every call)

Raises¶

ValueError: either for a negative number of elements (not physically possible) or for an unknown mode

calculate_array_factor(directions, pointing_directions, frequency, tile_beams=None)¶

Calculates the station array factor in M directions.

Parameters¶

directionsndarray: 3xM array of unit length vectors that decribe the directions in ENU coordinates
frequencyfloat: Frequency of the measurement
tile_beamsNone or ndarray, optional: If set to None (default) this disables the element beams and only the array factor is returned. Otherwise, give an N x M array of element responses in the requested directions
pointing_directionsndarray: 3xM array of unit length vectors that decribe the direction of the pointing center in ENU coordinates.

Returns¶

ndarray: M length response

calculate_response(directions, frequency, antenna_mode=None, pointing_directions=None, calculate_all_tiles=True)¶

Calculates the full station beam in M directions.

Parameters¶

directionsndarray: 3xM array of unit length vectors that decribe the directions in ENU coordinates
frequencyfloat: Frequency of the measurement
antenna_modeNone or str, optional: If set to None (default) this disables the element beams and only the array factor is returned. Otherwise, give the requested antenna type.
pointing_directionsndarray, optional: 3xM array of unit length vectors that decribe the direction of the pointing center in ENU coordinates. Default is None (drift-scan)
calculate_all_tilesbool, optional: If set, all tile beams are computed separately (allows for antenna drift), if unset, a tile beam pattern is reused for all tiles. Default is False.

Returns¶

ndarray: M length response

get_element_property(property)¶: Helper function for the element list. Retrieves a property of the underlying elements.

radec_to_ENU(time, right_ascension=None, declination=None, temporal_offset=0, number_of_timesteps=1, tracking_direction=False)¶

Calculates a sky direction in the stations ENU frame at a given time

Parameters¶

timestr: Start time of observation in UTC format (YYYY-MM-DDThh:mm:ss, example: 2024-07-04T19:25:00)
right_ascensionfloat, optional: RA in deg, default is None (for if the phase center is observed)
declinationfloat, optional: dec in deg, default is None (for if the phase center is observed)
temporal_offsetfloat: Time resolution in s.
number_of_timestepsint: Number of simulated time intervals, default is 1
tracking_directionbool: If set, compute the direction of the phase center instead of the Ra,Dec. Default is False.

Returns¶

ndarray: source direction unit vector in ENU

reset_elements()¶: Resets all elements in the tile to the common pointing and unit gain.

set_ENU_positions()¶: Sets ENU (East-North-Up) coordinates.

set_array_position(station)¶

Sets position of station within the interferometric array compared to another station (so the position is the ENU position of self in the reference frame of the other station)

Parameters¶

stationStation object: reference station

set_element_property(property, values, same_value=False)¶: Helper function for the element list. Sets a property of the underlying elements.

update_station_pointing(new_pointing_ra=None, new_pointing_dec=None)¶

Updates station_pointing (including tile pointing). If the pointing is set to None, the telescope operates in drift-scan mode.

Parameters¶

pointing_rafloat, optional: Right ascension of the phase center in deg, default is None
pointing_decfloat, optional: Declination of the phase center in deg, default is None

class shimmerr.array.Tile(positions, tracking, gain=1 + 0j)¶

Bases: object

A class that represents the analogue beamformer elements in the array.

Attributes¶

p: list: Contains the 3D position of the tile in ECEF (Earth-Centered Earth-Fixed) coordinates
p_ENU: list: Contains the 3D position of the tile in ENU (East-North-Up) coordinates
g: complex: Complex gain of the element
d: ndarray: Complex pointing of the tile (in Ra, Dec)

__init__(positions, tracking, gain=1 + 0j)¶

Parameters¶

positionslist: Contains the 3D position of the elements in ECEF coordinates
pointingcomplex, optional: Complex pointing of the tile (in ENU coordinates)
gaincomplex, optional: Complex gain of the tile (shared by all elements), by default 1

calculate_response(directions, frequency, antenna_beams=None, pointing_directions=None)¶

Calculates the tile response or array factor in M directions.

directionsndarray
3xM array of unit length vectors that decribe the directions in ENU coordinates

frequencyfloat
Frequency of the measurement

antenna_beamsNone or ndarray, optional
If set to None (default) this disables the element beams and only the array factor is returned. Otherwise, give an N x M array of element responses in the requested directions

pointing_directionsndarray, optional

3xM array of unit length vectors that decribe the direction of the pointing center in ENU coordinates. Default is None (drift-scan)

ndarray: M length response

get_element_property(property)¶: Helper function for the element list. Retrieves a property of the underlying elements.

reset_elements()¶: Resets all elements in the tile to have unit gain

set_ENU_positions(rotation_matrix, station_position)¶: Calculates the ENU (East-North-Up) coordinates of all elements and the tile itself, based on the station rotation matrix from ECEF to ENU.

set_element_property(property, values, same_value=False)¶: Helper function for the element list. Sets a property of the underlying elements.

update_tile_gain(new_gain)¶

shimmerr.array.calculate_array_factor_contribution(positions, gains, k, directions)¶

Calculates the array factor contributions of all elements and passes them separately (not summed).

Parameters¶

positionsndarray: 3xN array of element positions (must be floats)
gainsndarray: N sized array of element gains (must be complex)
kfloat: wave number
directionsndarray: 3xM array of directions to calculate the response in

Returns¶

ndarray: N x M array with responses

shimmerr.calibration module¶

class shimmerr.calibration.DDEcal(array, reference_station, n_channels=1, n_times=1, uv_lambda=[250, 5000], antenna_mode='omnidirectional', n_iterations=50, tolerance=1e-06, update_speed=0.2, smoothness_scale=4000000.0)¶

Bases: object

A class that can run DDECal in a single polarisation, with various weighting schemes.

Attributes:¶

array: dict: Interferometer dictionary with Station objects as values.
reference_station: str: Name (AKA array key) of the station that should act as the reference for gain phases. Subtracting the phases of this station removes unitairy ambiguity.
n_channels: int: Number of channels per solution interval
n_times: int: Number of time steps per solution interval
uv_lambda: list: List containing the minimum and maximum baseline length used in calibration in lambda.
antenna_mode: str: Mode for the antenna in the calibration beam (see: Antenna objects).
n_iterations: int: Number of iterations for the algorithm.
tolerance: float: If the mean change rate of the gains drops below this number, the algorithm interprets it as convergence and stops the optimisation earlier than n_iterations.
update_spead: float: Number between 0 and 1 that determines how quick the gain solutions should update. A speed of 0 means no update, a speed of 1 means that the previous gain solution is not included in the update.
smoothness_scale: float: Width of the spectral regularisation kernel in MHz.

calculate_residuals(visibility_file, gain_path, skymodel, fname, data_path=None)¶

Calculate residuals with known gains

Parameters¶

visibility_filestr: filename that contains the visibilities (path + name).
gain_pathstr: path + filename of the gains
skymodelSkymodel object: Used for determining the calibration directions, see sources.py
fnamestr: output file name (including path)
data_pathstr, optional: basepath for the model and gains, by default None (inferred from the visibility file)

run_DDEcal(visibility_file, skymodel, reuse_predict=False, reweight_mode=None, fname=None, calculate_residual=True, data_path=None)¶

Perform DDECal

Parameters¶

visibility_filestr: filename that contains the visibilities (path + name)
skymodelSkymodel object: sources. Used for determining the calibration directions and possibly the predict, see sources.py
reuse_predictbool, optional: If True, the coherency model is read from disk, if False it is computed first, by default False
reweight_modestr, optional: Reweighting kernel (“abs”, “squared” or None), by default None - abs: robust calibrator (smooth with the expected beam response) - squared: smooth with the square of the model times gain - None: smooth with the gain
fnamestr, optional: Name of the output files. By default None (name is set to Calibration_<reweight_mode>_<smoothness_scale>).
calculate_residualbool, optional: Whether to also calculate the residual visibilities, by default True
data_pathstr, optional: basepath for the model and output, by default None (inferred from the visibility file)

shimmerr.export module¶

shimmerr.export.export_MS(array, visibility_file, output_file, template_name='/home/codex/brackenhoff/projects/beam_errors/beam_errors/files/LOFAR_HBA_Dutch_template.MS', DP3_binding='DP3')¶

Function that converts visbility CSVs from SHIMMERR into MS.

Parameters¶

arraydict: dictionary of Station objects that form the interferometer
visibility_filestr: path + filename of the csv with the stored visibilities
output_filestr: path + filename of the MS in which the visibilities should be output
template_namestr, optional: path + filename of the MS template. Currently SHIMMERR is only packages with LOFAR HBA, but another template van be supplied by the user. This will change the ELEMENT_FLAGGING, however, (see the _unflag_broken_tiles function), by default f”<SHIMMERR home directory>/files/LOFAR_HBA_Dutch_template.MS”
DP3_bindingstr, optional: binding to call DP3 from (for example if it should be called with a container), by default “DP3”

shimmerr.load_array module¶

shimmerr.load_array.load_LOFAR(mode='EoR', pointing_ra=None, pointing_dec=None)¶

Loads LOFAR HBA using coordinates from Michiel Brentjens’ LOFAR Antpos: https://github.com/brentjens/lofar-antenna-positions

Parameters¶

modestr, optional: Beamforming mode, can be “CS” (only core stations), “Dutch_tapered” (all Dutch stations, with the RS beamformed to act like a CS), “Dutch_sensitive” (all Dutch stations, with all tiles in the RS functioning), “international” (all LOFAR stations from Lofarantpos), or “EoR” (stations with baselines shorter than ~10 km, in tapered setting, corresponds to the Epoch of Reionization science case), by default “EoR”
pointing_rafloat, optional: Right ascension of the phase center in deg, by default None (drift-scan)
pointing_decfloat, optional: Declination of the phase center in deg, by default None (drift-scan)

Returns¶

dict: Dictionary of SHIMMERR Station objects

shimmerr.load_array.load_array_from_file(filepath, pointing_ra=None, pointing_dec=None)¶

Loads an array from a file supplied by the user. The file should be structured as follows: - Stations are separated by empty lines, and start with a name (so the first line of the station “paragraph” is a string with its name) - The rest of the block of a station consists of lines with 4 comma separated values. – The first is a tile identifier (any string) – The later 3 are antenna positions in ETRS coordinates – New tiles are automatically created when a new tile identifier is read Comments can be added with a # sign at the start of a line

Parameters¶

filepathstr: path + filename of the file that contains the array.
pointing_rafloat, optional: Right ascension of the phase center in deg, by default None (drift-scan)
pointing_decfloat, optional: Declination of the phase center in deg, by default None (drift-scan)

Returns¶

dict: Dictionary of SHIMMERR Station objects

shimmerr.metrics module¶

shimmerr.metrics.compute_realized_gains(directory_realized_responses, directory_ideal_responses, fname_realized_gains, patch_names=None)¶

Computes the “realised gains”, AKA the ratio between the true beam response and the calibration beam response. This is the “perfect” gain that perfectly calibrates a calibration patch. In reality, this gain can’t come out of calibration (solution intervals, noise, etc.), but it can be used to gauge gain calirbation errors NB: be careful that this uses beam _responses_ (one station) not the beam _models_ (baseline-based).

Parameters¶

directory_realized_responsesstr: Path of the directory with true beam responses
directory_ideal_responsesstr: Path of the directory with the calibration beam responses
fname_realized_gainsstr: filename to save the realized gains under
patch_nameslist, optional: list of strings with the names of the calibration directions in which the responses should be computed, by default None (uses all patches in the directory).

shimmerr.sources module¶

class shimmerr.sources.Patch(patch_right_ascension, patch_declination)¶

Bases: object

__init__(patch_right_ascension, patch_declination)¶

Class that contains a calibration patch (group/cluster of sources)

Parameters¶

patch_right_ascensionstr: RA in HH:MM:SS.SSS
patch_declinationstr: Dec in +-DD.MM.SS.SSS

add_source(source_name, right_ascension, declination, brightness, reference_frequency, spectral_index, logSI)¶

Creates a source within the Patch. The brightness is computed as for a LOFAR sourcedb (see https://www.astron.nl/lofarwiki/doku.php?id=public:user_software:documentation:makesourcedb)

Parameters¶

right_ascensionstr: RA in HH:MM:SS.SSS
declinationstr: Dec in +-DD.MM.SS.SSS
brightnessfloat: Source brightness (I0)
reference_frequencyfloat: v0
spectral_indexstr: str in the form [c0,c1,c2]
logSIbool: whether the spectral index is logarithmic

class shimmerr.sources.Skymodel(filename)¶

Bases: object

__init__(filename)¶

Reads a skymodel from disk and converts it into a SHIMMERR sky model.

Parameters¶

filenamestr: path + filename of the sky model

join_patches(patch_names, joint_name=None, joint_ra=None, joint_dec=None)¶

parse_formatstring(string)¶

class shimmerr.sources.Source(right_ascension, declination, brightness, reference_frequency, spectral_index, logSI)¶

Bases: object

__init__(right_ascension, declination, brightness, reference_frequency, spectral_index, logSI)¶

Class to describe a sky-model source. The brightness is computed as for a LOFAR sourcedb (see https://www.astron.nl/lofarwiki/doku.php?id=public:user_software:documentation:makesourcedb)

Parameters¶

right_ascensionstr: RA in HH:MM:SS.SSS
declinationstr: Dec in +-DD.MM.SS.SSS
brightnessfloat: Source brightness (I0)
reference_frequencyfloat: v0
spectral_indexstr: str in the form [c0,c1,c2]
logSIbool: whether the spectral index is logarithmic

static linear_spectral_index_brightness(frequency, brightness, reference_frequency, spectral_index)¶: Helper function to calculate the brightness as a function of frequency for a linear spectral index

static logarithmic_spectral_index_brightness(frequency, brightness, reference_frequency, spectral_index)¶: Helper function to calculate the brightness as a function of frequency for a logarithmic spectral index

static parse_declination(declination_string)¶: Helper function to convert the Dec to degrees

static parse_right_ascension(right_ascension_string)¶: Helper function to convert the RA to degrees

shimmerr.visibility module¶

shimmerr.visibility.add_thermal_noise(filename, data_path, sefd, seed)¶

Adds thermal noise to the visibilities

Parameters¶

filenamestr: directory of the relevant visibilities. The input file with be at <path>/<filename>/full_model.csv, and the output file at <path>/<filename>/data.csv
data_pathstr: data path (see filename)
sefdfloat: system equivalent flux density of the noise
seedint: seed for the randum number generator

shimmerr.visibility.calculate_directions(station, start_time_utc, time_resolution, number_of_timeslots, right_ascensions, declinations, n_jobs)¶: Helper function to generate source directions and tracking directions in an easy format

shimmerr.visibility.get_time_labels(start_time_utc, duration, time_resolution)¶: Helper function to generate time labels for the visibilities

shimmerr.visibility.predict_data(array, skymodel, frequencies, start_time_utc, filename, data_path='./data/predictions', time_resolution=2, duration=12, antenna_mode='omnidirectional', basestation=None, reuse_tile_beam=False, SEFD=4200.0, save_response=True, seed=None, n_jobs=-1)¶

Performs a full visibility predict from a sky model and interferometer.

Parameters¶

arraydict: dict of SHIMMERR stations that describe the interferometer (see array.py and load_array.py)
skymodeldict: dict of SHIMMERR patches that describe the sources in the sky (see sources.py)
frequencieslist or ndarray of floats: Frequencies at which to simulate the array. We simulate no smearing etc.
start_time_utcstr: UTC start time of the observation in format YYYY-MM-DDThh:mm:ss, example: 2024-07-04T19:25:00
filenamestr: name of the folder in which the visibilities should be saved
data_pathstr, optional: folder in which the destination folder should be saved, by default “./data/predictions”
time_resolutionint, optional: time resolution in seconds, by default 2
durationint, optional: observation duration in hours, by default 12
antenna_modestr, optional: beam mode for the lowest level elements, by default “omnidirectional”
basestationstr, optional: name of the station used as the ‘array center’, by default None (selects the first station in the array dictionary)
reuse_tile_beambool, optional: If set, uses the same tile model for all tiles in a stationm. This does not allow for intra-tile variation, but does speed up the computation. Recommended for the calibration model predict, by default False (all tiles computed separately)
SEFDfloat, optional: System equivalent flux density of the noise in Jy. Set to None to disable noise, by default 4.2e3
save_responsebool, optional: toggles whether the station responses are saved to enable computing the expected gain. Default is True.
seedint, optional: seed for the random number generator that creates the noise, set to anything but None for reproducability, by default None
n_jobsint, optional: Number of prediction processes that are allowed to run in parallel (ideally equal to the number of CPU cores), by default -1 (all cores used)

shimmerr.visibility.predict_patch_visibilities(array, skymodel, frequencies, start_time_utc, filename, data_path='./data/predictions', time_resolution=2, duration=12, antenna_mode='omnidirectional', basestation=None, reuse_tile_beam=False, save_response=True, n_jobs=-1)¶

Predicts noiseless visibilities of each patch and saves each patch to disk.

Parameters¶

arraydict: Dictionary containing Station objects
skymodelSkymodel object: skymodel to be simulated
frequencieslist or ndarray of floats: Frequencies at which to simulate the array. We simulate no smearing etc.
start_time_utcstr: UTC start time of the observation in format YYYY-MM-DDThh:mm:ss, example: 2024-07-04T19:25:00
filenamestr: name of the folder in which the visibilities should be saved
data_pathstr, optional: folder in which the destination folder should be saved, by default “./data/predictions”
time_resolutionint, optional: time resolution in seconds, by default 2
durationint, optional: observation duration in hours, by default 12
antenna_modestr, optional: beam mode for the lowest level elements, by default “omnidirectional”
basestationstr, optional: name of the station used as the ‘array center’, by default None (selects the first station in the array dictionary)
prediction_batch_sizeint, optional: approximate batch size for each visibility prediction after beam calculation. This is a trade off between speed and memory virtualization. The batch will become an integer multiple of the number of stations * number of sources, so this number may be exceeded if one of such batches is larger than the specified value, by default 10000.
save_responsebool, optional: toggles whether the station responses are saved to enable computing the expected gain. Default is True.

shimmerr.visibility.process_batch(batch, source_powers)¶

shimmerr.visibility.record_beams(df, new_batch, first_frequency, last_frequency, first_station, file_path)¶: Helper function to write the response beam files

shimmerr.visibility.subtract_visibilities(filename_in_1, filename_in_2, filename_out, common_path='')¶

Function to take the difference between visibilities (for source subtraction)

Parameters¶

filename_in_1str: filename of the visibilities from which the sources must be subtracted
filename_in_2str: filename of the visibilities with the sources that must be subtracted
filename_outstr: filename where the result must be stored
common_pathstr, optional: path for these files (the paths can also be added to the filename, in which case this would be root), by default “”

shimmerr.visibility.sum_patches(filename, data_path, skymodel)¶

Sums all patch models to create a full sky visibility prediction

Parameters¶

filenamestr: directory of the relevant visibilities. The summed file with be at <path>/<filename>/full_model.csv, and the patch models must be at <path>/<filename>/patch_models
data_pathstr: data path (see filename)
skymodeldict: SHIMMERR sky model (used for patch names only)

shimmerr.visualization module¶

shimmerr.visualization.get_beam(beam_value_mode, beam_plot_mode, station, frequency, directions, phase_center, antenna_mode, tile_number, antenna_number, calculate_all_tiles)¶

Helper function to calculate the beam so it can be plot

Parameters¶

beam_value_modestr, optional: The way in which the beam should be calculated “element”, “tile” (array factor), “station” (array factor), “array_factor” (tile and station array factors combined), or “full” (elements and array factors), by default “full”
beam_plot_modestr, optional: The way in which the beam should be displayed (“power” of “voltage” in dB and real and imaginary in linear scale), by default “power”
stationStation object: Station
frequencyfloat or int, optional: measurement frequency to plot the beam for, by default 150e6
directionsndarray: Array with directions in which to calculate the beam, should be 3xNdir
phase_centerndarray: Array with the pointing direction in which to calculate the beam, should be 3xNdir
antenna_modeNone or str, optional: Gives the shape of the element beam, by default None
tile_numberint, optional: Which tile in the station to display for tile/element option, by default 0
antenna_numberint, optional: Which element in the chosen tile to display (for element option), by default 0
calculate_all_tilesbool: If set, all tile beams are computed separately (allows for intra-tile variations), if unset all tile beams are identical (faster computation)

Returns¶

ndarray: beam values that can be plotted
str: colorbar label

shimmerr.visualization.plot_convergence(results, plot_folder, name)¶

Plot the convergence of a calibration run

Parameters¶

resultsdict: Results as output by the DDECal.run (see calibration.py)
plot_folderstr: path where the plot should be save
namestr: filename of the plot

shimmerr.visualization.plot_gain_error(fname_gains, fname_true_gains, plot_folder, name, reference_station='CS002HBA0', amplitude_lims=[0, 2], phase_lims=[-3.141592653589793, 3.141592653589793])¶

Creates a plot of the error in estimated gains using the ideal gains (ratio between true beam response and claibration beam)

Parameters¶

fname_gainsstr: path + filename where the estimated gains are stored
fname_true_gainsstr: path + filename where the ideal gains are stored (see metrics.py)
plot_folderstr: directory where the plot is to be stored
namestr: filename of the plot
reference_stationstr, optional: name fo the reference station used to remove unitairy ambiguity by using it as zero-phase, by default “CS002HBA0”
amplitude_limslist, optional: range of amplitude colorbar, by default [0, 2]
phase_limslist, optional: range of phase colorbar, by default [-np.pi, np.pi]

shimmerr.visualization.plot_gains(fname, plot_folder, name, amplitude_lims=[0, 2], phase_lims=[-3.141592653589793, 3.141592653589793])¶

Function to plot gains

Parameters¶

fnamestr: path + filename of the results object that contians the gails
plot_folderstr: Folder where the plot should be saved
namestr: name of the plot
amplitude_limslist, optional: range of the gain amplitude in the plot, by default [0, 2]
phase_limslist, optional: range of the gain phase in the plot, by default [-np.pi, np.pi]

shimmerr.visualization.plot_spatial_beam(station, n_altitude, n_azimuth, frequency=150000000.0, antenna_mode=None, beam_plot_mode='power', beam_value_mode='full', tile_number=0, antenna_number=0, points_of_interest=[], plot_title=None, time='2024-01-01T00:00:00', calculate_all_tiles=True, **kwargs)¶

Helper function to create plots of station beams easily

Parameters¶

stationStation object: Station
n_altitudeint: Number of points in the altitude sweep (more is higher resolution)
n_azimuthint: Number of points in the azimuth sweep (similar to n_altitude)
frequencyfloat or int, optional: measurement frequency to plot the beam for, by default 150e6
antenna_modeNone or str, optional: Gives the shape of the element beam, by default None
beam_plot_modestr, optional: The way in which the beam should be displayed (“power” of “voltage” in dB and real and imaginary in linear scale), by default “power”
beam_value_modestr, optional: The way in which the beam should be calculated “element”, “tile” (array factor), “station” (array factor), “array_factor” (tile and station array factors combined), or “full” (elements and array factors), by default “full”
tile_numberint, optional: Which tile in the station to display for tile/element option, by default 0
antenna_numberint, optional: Which element in the chosen tile to display (for element option), by default 0
plot_title: str: Title of the plot
points_of_interestlist, optional: list of directions that should be highlighted in the plot. For example the pointing direction or a bright source, by default [] (no highlighted points)

shimmerr.visualization.plot_spectrotemporal_beam(station, right_ascension, declination, frequencies=array([1.34100e+08, 1.34295e+08, 1.34490e+08, 1.34685e+08, 1.34880e+08, 1.35075e+08, 1.35270e+08, 1.35465e+08, 1.35660e+08, 1.35855e+08, 1.36050e+08, 1.36245e+08, 1.36440e+08, 1.36635e+08, 1.36830e+08, 1.37025e+08, 1.37220e+08, 1.37415e+08, 1.37610e+08, 1.37805e+08, 1.38000e+08, 1.38195e+08, 1.38390e+08, 1.38585e+08, 1.38780e+08, 1.38975e+08, 1.39170e+08, 1.39365e+08, 1.39560e+08, 1.39755e+08, 1.39950e+08, 1.40145e+08, 1.40340e+08, 1.40535e+08, 1.40730e+08, 1.40925e+08, 1.41120e+08, 1.41315e+08, 1.41510e+08, 1.41705e+08, 1.41900e+08, 1.42095e+08, 1.42290e+08, 1.42485e+08, 1.42680e+08, 1.42875e+08, 1.43070e+08, 1.43265e+08, 1.43460e+08, 1.43655e+08, 1.43850e+08, 1.44045e+08, 1.44240e+08, 1.44435e+08, 1.44630e+08, 1.44825e+08, 1.45020e+08, 1.45215e+08, 1.45410e+08, 1.45605e+08, 1.45800e+08, 1.45995e+08, 1.46190e+08, 1.46385e+08, 1.46580e+08]), utc_starttime='2024-07-04T21:35:00', time_resolution=2, number_of_timeslots=400, antenna_mode=None, beam_plot_mode='power', beam_value_mode='full', tile_number=0, antenna_number=0, plot_title=None, calculate_all_tiles=True, **kwargs)¶

Helper function to create plots of station beams easily

Parameters¶

stationStation object: Station
right_ascentionfloat: Target RA in degrees
declinationfloat: Target dec in degrees
frequenciesndarray, optional: channel central frequencies to plot the beam for in Hz. Default is 195kHz channels between 134.1 and 146.7 MHz (LOFAR-EoR redshift bin 2).
utc_starttimstr: Observing time in UTC format (YYYY-MM-DDThh:mm:ss. Default is “2024-07-04T21:35:00”
time_resolutionfloat: Time resolution at which to plot the beam in seconds. Default is 2.
number_of_timeslotsint: Number of timeslots (of size time_resolution) to plot. Default is 400
antenna_modeNone or str, optional: Gives the shape of the element beam, by default None
beam_plot_modestr, optional: The way in which the beam should be displayed (“power” of “voltage” in dB and real and imaginary in linear scale), by default “power”
beam_value_modestr, optional: The way in which the beam should be calculated “element”, “tile” (array factor), “station” (array factor), “array_factor” (tile and station array factors combined), or “full” (elements and array factors), by default “full”
tile_numberint, optional: Which tile in the station to display for tile/element option, by default 0
antenna_numberint, optional: Which element in the chosen tile to display (for element option), by default 0

shimmerr.visualization.plot_visibility(file, station_pairs, magnitude_range=[None, None], phase_range=[-3.141592653589793, 3.141592653589793], **kwargs)¶

Plots a visibility

Parameters¶

filestr: pth + filename of the visibility
station_pairslist: list of tuples with the baseline to be plotted
magnitude_rangelist, optional: range of the magnitude scale, by default [None, None]
phase_rangelist, optional: range of the phase scale, by default [-np.pi, np.pi]

shimmerr package¶

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shimmerr.array module¶

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shimmerr.calibration module¶

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shimmerr.export module¶

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shimmerr.load_array module¶

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shimmerr.metrics module¶

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shimmerr.sources module¶

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shimmerr.visibility module¶

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shimmerr.visualization module¶

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Module contents¶