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