SSAQuery

class pyvo.dal.ssa.SSAQuery(baseurl, version='1.0', request='queryData')[source]

Bases: pyvo.dal.query.DALQuery

a class for preparing an query to an SSA service. Query constraints are added via its service type-specific properties and methods. Once all the constraints are set, one of the various execute() functions can be called to submit the query and return the results.

The base URL for the query, which controls where the query will be sent when one of the execute functions is called, is typically set at construction time; however, it can be updated later via the baseurl to send a configured query to another service.

In addition to the attributes described below, search parameters can be set generically by name via dict semantic. The class attribute, std_parameters, list the parameters defined by the SSA standard.

The typical function for submitting the query is execute(); however, alternate execute functions provide the response in different forms, allowing the caller to take greater control of the result processing.

initialize the query object with a baseurl and request type

Attributes Summary

band the spectral bandpass given in a range-list format in units of
dec the declination part of the position constraint (default: None).
format the desired format of the images to be returned. This will be in the
pos the position (POS) constraint as a 2-element tuple denoting RA and
ra the right ascension part of the position constraint (default: None).
size the diameter of the search region specified in decimal degrees
std_parameters
time the time coverage given in a range-list format using a restricted

Attributes Documentation

band

the spectral bandpass given in a range-list format in units of meters

Examples of proper format include:

0.20/0.21.5 a wavelength range that includes 21cm
2.7E-7/0.13 a bandpass from optical to radio
dec

the declination part of the position constraint (default: None). If this is set but ra has not been set yet, ra will be set to 0.0.

format

the desired format of the images to be returned. This will be in the form of a commna-separated list of MIME-types or one of the following special values.

value meaning
all all formats available
compliant any SSA data model compliant format
native the native project specific format for the spectrum
graphic any of the graphics formats: JPEG, PNG, GIF
votable the SSA VOTable format
fits the SSA-compliant FITS format
xml the SSA native XML serialization
metadata no images requested; only an empty table with fields properly specified
pos

the position (POS) constraint as a 2-element tuple denoting RA and declination in decimal degrees. This defaults to None.

ra

the right ascension part of the position constraint (default: None). If this is set but dec has not been set yet, dec will be set to 0.0.

size

the diameter of the search region specified in decimal degrees

std_parameters = ['REQUEST', 'VERSION', 'POS', 'SIZE', 'BAND', 'TIME', 'FORMAT', 'APERTURE', 'SPECRP', 'SPATRES', 'TIMERES', 'SNR', 'REDSHIFT', 'VARAMPL', 'TARGETNAME', 'TARGETCLASS', 'FLUXCALIB', 'WAVECALIB', 'PUBID', 'CREATORID', 'COLLECTION', 'TOP', 'MAXREC', 'MTIME', 'COMPRESS', 'RUNID']
time

the time coverage given in a range-list format using a restricted subset of ISO 8601.

Examples of proper format include:

2003/2009 covers years 2003-09, inclusive
2003-02/2003-04 covers Feb. through April in 2003
2003-05-02/2010-09-21 covers a range of days
2001-05-02T12:21:30/2010 provides second resolution