SSA xs ssap XML Schema used to describe the capabilities of a service instance conforming to the Simple Spectral Access (SSA) protocol. The capabilities of an SSA service implementation. The category indicating the level to which this instance complies with the SSA standard. Allowed values are "query", "minimal", and "full". See definitions of allowed values for details. The category specifying where the data originally came from. Allowed values are "survey", "pointed", "custom", "theory", "artificial" The category that describes the process used to produce the dataset. Typically this describes only the processing performed by the data service, but it could describe some additional earlier processing as well, e.g., if data is partially precomputed. Allowed values are "archival", "cutout", "filtered", "mosaic", "projection", "spectralExtraction", "catalogExtraction" Identifiers of spatial reference frames that can be used in the POS parameter. The identifiers must be taken from the vocabulary http://www.ivoa.net/rdf/refframe. At least one recognized value must be listed when the service supports POS. With SSA v1.1, ICRS must be supported in that case; thus, this list must include at least this value. The largest search radius, in degrees, that will be accepted by the service without returning an error condition. Not providing this element or specifying a value of 180 indicates that there is no restriction. Not providing a value is the prefered way to indicate that there is no restriction. The hard limit on the largest number of records that the query operation will return in a single response. Not providing this value means that there is no effective limit. This does not refer to the total number of spectra in the archive but rather maximum number of records the service is capable of returning. A limit that is greater than the number of spectra available in the archive is equivalent to their being no effective limit. (See RM, Hanisch 2007.) The largest number of records that the service will return when the MAXREC parameter not specified in the query input. Not providing a value means that the hard limit implied by maxRecords will be the default limit. The largest aperture that can be supported upon request via the APERTURE input parameter by a service that supports the spectral extraction creation method. A value of 180 or not providing a value means there is no theoretical limit. Not providing a value is the preferred way to indicate that there is no limit. The maximum spectrum file size in bytes that will be returned. Not providing a value indicates that there is no effective limit the size of files that can be returned. This is primarily relevant when spectra are created on the fly (see creationType). If the service provides access to static spectra, this should only be specified if there are spectra in the archive that can be searched for but not returned because they are too big. a set of query parameters that is expected to produce at least one matched record which can be used to test the service. The allowed values for indicating the level at which a service instance complies with the SSA standard. The service supports all of the capabilities and features of the SSA protocol identified as "must" in the specification, except that it does not support returning data in at least one SSA-compliant format. This level represents the lowest level of compliance. The service supports all of the capabilities and features of the SSA protocol identified as "must" in the specification. In brief, this includes: * implementing the GET interface, * support the parameters POS, SIZE, TOME, BAND, and FORMAT * includes all mandatory metadata fields in query response * supports getData method retrieval in at least one SSA-compliant format * supports the "FORMAT=METADATA" metadata query. This level represents the middle level of compliance. The service supports all of the capabilities and features of the SSA protocol identified as "must" or "should" in the specification. This level represents the highest level of compliance. The defined categories that specify where the spectral data originally came from. A survey dataset, which typically covers some region of observational parameter space in a uniform fashion, with as complete as possible coverage in the region of parameter space observed. A pointed observation of a particular astronomical object or field. Typically, these are instrumental observations taken as part of some PI observing program. The data quality and characteristics may be variable, but the observations of a particular object or field may be more extensive than for a survey. Data which has been custom processed, e.g., as part of a specific research project. Theory data, or any data generated from a theoretical model, for example a synthetic spectrum. Artificial or simulated data. This is similar to theory data but need not be based on a physical model, and is often used for testing purposes. The entire archival or project dataset is returned. Transformations such as metadata or data model mediation or format conversions may take place, but the content of the dataset is not substantially modified (e.g., all the data is returned and the sample values are not modified). The dataset is subsetted in some region of parameter space to produce a subset dataset. Sample values are not modified, e.g., cutouts could be recombined to reconstitute the original dataset. The data is filtered in some fashion to exclude portions of the dataset, e.g., passing only data in selected regions along a measurement axis, or processing the data in a way which recomputes the sample values, e.g., due to interpolation or flux transformation. Filtering is often combined with other forms of processing, e.g., projection. Data from multiple non- or partially-overlapping datasets are combined to produce a new dataset. Data is geometrically warped or dimensionally reduced by projecting through a multidimensional dataset. Extraction of a spectrum from another dataset, e.g., extraction of a spectrum from a spectral data cube through a simulated aperture. Extraction of a catalog of some form from another dataset, e.g., extraction of a source catalog from an image, or extraction of a line list catalog from a spectrum (not valid for a SSA service). A query to be sent to the service the center position the search cone given in decimal degrees. the size of the search radius. Fully specified test query formatted as an URL argument list in the syntax specified by the SSA standard. The list must exclude the REQUEST argument which is assumed to be set to "queryData". This value must be in the form of name=value pairs delimited with ampersands (&). A query may then be formed by appending to the base URL the request argument, "REQUEST=queryData&", followed by the contents of this element. a position in the sky to search. The longitude (e.g. Right Ascension) of the center of the search position in decimal degrees. The latitude (e.g. Declination) of the center of the search position in decimal degrees. the coordinate system reference frame name indicating the frame to assume for the given position. If not provided, ICRS is assumed.