ztforce.ztf_images

ZTF IRSA metadata queries, URL construction, FITS/PSF download with retry.

Attributes

`_IRSA_BASE`
`_DOWNLOAD_TIMEOUT_SEC`
`_BAND_TO_FILTERCODE`
`_REQUIRED_METADATA_COLS`

Functions

`query_sci_metadata`(→ pandas.DataFrame)	Query ZTF IRSA for all science exposures covering (ra, dec) in band.
`build_sci_url`(→ str)	Construct the IRSA IBE URL for a science image product.
`_validate_fits`(→ bool)	Return True if the FITS file opens without error.
`_download_with_retry`(→ pathlib.Path)	Download url to dest, retrying on failure with exponential backoff.
`download_fits`(→ pathlib.Path)	Download a FITS cutout to dest.
`download_psf_sidecar`(→ pathlib.Path)	Download a DAOPhot PSF sidecar (.psf) file to dest.

Module Contents

_IRSA_BASE = 'https://irsa.ipac.caltech.edu/ibe/data/ztf/products'[source]

_DOWNLOAD_TIMEOUT_SEC = 120[source]

_BAND_TO_FILTERCODE[source]

_REQUIRED_METADATA_COLS[source]

query_sci_metadata(ra: float, dec: float, band: str, config: ztforce.config.ZTForceConfig, search_radius_deg: float = 0.01) → pandas.DataFrame[source]

Query ZTF IRSA for all science exposures covering (ra, dec) in band.

Returns a DataFrame sorted by obsjd ascending. Raises NoImagesFoundError when no images are found.

build_sci_url(row: pandas.Series, ra: float, dec: float, suffix: str = 'sciimg.fits', cutout_size_arcmin: float = DEFAULT_CUTOUT_SIZE_ARCMIN) → str[source]

Construct the IRSA IBE URL for a science image product.

For FITS files a cutout query is appended so that only a cutout_size_arcmin × cutout_size_arcmin region centred on (ra, dec) is downloaded. PSF sidecar files are returned in full (they are small text files that describe the whole quadrant).

_validate_fits(path: pathlib.Path) → bool[source]: Return True if the FITS file opens without error.

_download_with_retry(url: str, dest: pathlib.Path, config: ztforce.config.ZTForceConfig, validate: bool = True) → pathlib.Path[source]: Download url to dest, retrying on failure with exponential backoff.

download_fits(url: str, dest: pathlib.Path, config: ztforce.config.ZTForceConfig) → pathlib.Path[source]: Download a FITS cutout to dest.

download_psf_sidecar(url: str, dest: pathlib.Path, config: ztforce.config.ZTForceConfig) → pathlib.Path[source]: Download a DAOPhot PSF sidecar (.psf) file to dest.