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lofar_uvw_generator

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  • LOFAR UVW Generator

    The software is able to generate UVW coverage given a series of stations names or antenna fields. Furthermore, the repository contains additional tools that can be used to source the UVW coverage data generation on some pre existent observation.

    The code is also able to compute UV coverage summary parameter such as the UV filling factor or the UV eccentricity. Please refer to ObsCoreExtensionForVisibilities for more information regarding such parameters.

    Scrips available in this repository

    lofargen.py

    Generates random UVW coverage choosing randomly given a set of parameters. Such parameters are:

    • n_antennas
    • source_coordinates
    • frequency
    • max_baseline_length
    • observation_duration
    • array_coordinates

    The last two parameters are mandatory and represent the list of the the antenna coordinates and the duration of the observation.

    If additionally to the summary table also summary uvw plots are requested the generation can be toggled with --make_uvw_plot.

    Here after the usage:

    usage: Generate uvw and compute eccentricity and filling factor of the uvw plane
           [-h] [--n_antennas N_ANTENNAS]
           [--source_coordinates SOURCE_COORDINATES] [--make_uvw_plot]
           [--random_seed RANDOM_SEED] [--frequency FREQUENCY]
           [--max_baseline_length MAX_BASELINE_LENGTH]
           [--save_image_to SAVE_IMAGE_TO]
           array_coordinates observation_duration
    
    positional arguments:
      array_coordinates     coordinate list of the array elements
      observation_duration  duration of the observation in minutes
    
    optional arguments:
      -h, --help            show this help message and exit
      --n_antennas N_ANTENNAS
                            antenna sample size
      --source_coordinates SOURCE_COORDINATES
                            source_coordinates
      --make_uvw_plot
      --random_seed RANDOM_SEED
                            seed for the random number generator
      --frequency FREQUENCY
                            frequency in MHz
      --max_baseline_length MAX_BASELINE_LENGTH
                            max baseline length in m
      --save_image_to SAVE_IMAGE_TO

    lofargen_from_file.py

    Generates the UVW coverage given an input file containing the following columns:

    Column name Description
    SASID
    STARTTIME
    ENDTIME
    BEAMNUMBER
    FILTER LOFAR filter
    ANTENNASET LOFAR antennaset (e.g. HBA_Dual)
    RIGHTASCENSION
    DECLINATION
    STATIONS comma separeted list of stations

    The parameters needed for the execution of the script are the following:

    
    usage: Generate uvw and compute eccentricity and filling factor of the uvw plane
           [-h] [--make_uvw_plot] [--print_n_rows] [--start_row START_ROW]
           [--end_row END_ROW] [--save_image_to SAVE_IMAGE_TO]
           [--full_table FULL_TABLE]
           station_field observation_table
    
    positional arguments:
      station_field         coordinate list of the array elements
      observation_table     table with the observation information
    
    optional arguments:
      -h, --help            show this help message and exit
      --make_uvw_plot
      --print_n_rows        print nrows and exits
      --start_row START_ROW
      --end_row END_ROW
      --save_image_to SAVE_IMAGE_TO
      --full_table FULL_TABLE where to store the full table containing all the 
                              parameters
    

    lofarquery_lta.py

    Queries the LOFAR LTA to produce the file that serves as a source for the lofargen_from_file.py script.

    To use it the LTA credentials are required and can be specified via a configuration file who has to have the following structure:

    [global]
    database_user        : [username]
    database_password    : [password]

    The script has the following parameters:

    usage: lofarquery_lta.py [-h] [--config CONFIG] [--verbose]
                             [--chunk_size CHUNK_SIZE]
                             outfile
    
    Query the LTA to obtain the dataproduct list
    
    positional arguments:
      outfile               where to store the queried table
    
    optional arguments:
      -h, --help            show this help message and exit
      --config CONFIG       configuration file where the credentials are stored
      --verbose             set verbose logging level
      --chunk_size CHUNK_SIZE
                            save data in the csv in chunks of rows