generate_injection_catalog

lsst.source.injection.generate_injection_catalog(ra_lim: Sequence[float], dec_lim: Sequence[float], wcs: SkyWcs = None, number: int = 1, density: int | None = None, seed: Any = None, log_level: int = 20, **kwargs: Any) → Table

Generate a synthetic source injection catalog.

This function generates a synthetic source injection catalog from user supplied input parameters. The catalog is returned as an astropy Table.

On-sky source positions are generated using the quasi-random Halton sequence. By default, the Halton sequence is seeded using the product of the right ascension and declination limit ranges. This ensures that the same sequence is always generated for the same limits. This seed may be overridden by specifying the seed parameter.

A unique injection ID is generated for each source. The injection ID encodes two pieces of information: the unique source identification number and the version number of the source as specified by the number parameter. To achieve this, the unique source ID number is multiplied by 10**n such that the sum of the multiplied source ID number with the unique repeated version number will always be unique. For example, an injection catalog with number = 3 versions of each source will have injection IDs: 0, 1, 2, 10, 11, 12, 20, 21, 22, etc. If number = 20, then the injection IDs will be: 0, 1, 2, …, 17, 18, 19, 100, 101, 102, etc. If number = 1 (default) then the injection ID will be a simple sequential list of integers.

Parameters:
ra_limSequence [float]

The right ascension limits of the catalog in degrees.

dec_limSequence [float]

The declination limits of the catalog in degrees.

wcslsst.afw.geom.SkyWcs, optional

The WCS associated with these data. If not given or None (default), the catalog will be generated using Cartesian geometry.

numberint, optional

The number of times to generate each unique combination of input parameters. The default is 1 (i.e., no repeats). This will be ignored if density is specified.

densityint | None, optional

The desired source density in sources per square degree. If given, the number parameter will be ignored. Instead, the number of unique parameter combination generations will be calculated to achieve the desired density. The default is None (i.e., no density calculation).

seedAny, optional

The seed to use for the Halton sequence. If not given or None (default), the seed will be set using the product of the right ascension and declination limit ranges.

log_levelint, optional

The log level to use for logging.

**kwargsAny

The input parameters used to generate the catalog. Each parameter key will be used as a column name in the catalog. The values are the unique values for that parameter. The output catalog will contain a row for each unique combination of input parameters and be generated the number of times specified by number.

Returns:
tableastropy.table.Table

The fully populated synthetic source injection catalog. The catalog will contain an automatically generated injection_id column that is unique for each source. The injection ID encodes two pieces of information: the unique source identification number and the repeated version number of the source as defined by the number parameter.