Changes between Version 16 and Version 17 of Discovery/DiscoveryWebServiceMEDIN


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Timestamp:
06/11/09 10:33:49 (10 years ago)
Author:
mpritcha
Comment:

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  • Discovery/DiscoveryWebServiceMEDIN

    v16 v17  
    9494 
    9595=== Choice of search criteria: <termSearch>, <spatialSearch> and <temporalSearch> ===  
    96 The <searchCriteria> element acts as a container enabling the selection of one or more of <termSearch>, <spatialSearch> and <temporalSearch>. Searches of these 3 basic types may be used in combination. 
     96The <searchCriteria> element acts as a container enabling the selection of one or more of <termSearch>, <spatialSearch> and <temporalSearch>. Searches of these 3 basic types may be used in combination. Only one of each of <termSearch>, <spatialSearch> and <temporalSearch> may be included, but at least one of these three types of search must be supplied. 
    9797 
    9898==== termSearch ==== 
     
    147147 
    148148=== Spatial searching : <spatialOperator> and <boundingBox> === 
    149 The search may incorporate a spatial query to restrict results to those metadata records having spatial coverage(s) matching the search criteria defined by the <boundingBox> elements <limitNorth>, <limitEast>, <limitSouth>, <limitWest>. Coordinates should be in decimal lat/lon (* although an optional element <spatialReferenceSystem> may be populated with an entry from the [#spatialReferenceSystem spatialReferenceSystem] list to specify the spatial reference system (SRS) of the bounding box coordinates. (*Note : this feature is included for future development e.g. ability to supply spatial search coordinates in British National Grid coordinates. Currently the only supported SRS is EPSG:4326 (WGS84 lat/lon). 
    150 An optional <spatialOperator> may be included, populated with a term from the [#spatialOperatorList spatialOperatorList], defining the method by which the search should be compared to spatial coverage(s) related to metadata records. Note that in the discovery index database, metadata records may contain several spatial coverages, so a match can occur if any of the spatial coverages related to the metadata item match the criteria specified in the search. 
    151  
    152 If <spatialOperator> is omitted, but a valid <boundingBox> is supplied, the default operator applied is overlaps. Values for <limitNorth>, <limitSouth>, <limitEast> and <limitWest> should be given in decimal degrees latitude and longitude. <limitNorth> and <limitSouth> must be in the range -90.0 to +90.0, with <limitNorth> greater than <limitSouth>. <limitWest> and <limitEast> must be in the range -180.0 to 180.0 and <limitEast> should be greater than <limitWest>. Bounding boxes that span the -180 degree meridian, or the poles, are not currently supported. 
    153  
    154 Spatial searches (as a further restriction of "term" searches) are currently implemented by obtaining a resultset from the term search, obtaining a result set from the spatial search, then returning the intersection of the two result sets. 
     149The search may incorporate a spatial query to restrict results to those metadata records having spatial coverage(s) matching the search criteria defined by the <boundingBox> elements <limitNorth>, <limitSouth>, <limitEast> and <limitWest>. An optional element <spatialReferenceSystem> may be populated with an entry from the [#spatialReferenceSystem spatialReferenceSystem] list to specify an alternative spatial reference system (SRS) of the bounding box coordinates. (*Note : this feature is included for future development e.g. ability to supply spatial search coordinates in British National Grid coordinates. Currently the only supported SRS is EPSG:4326 (WGS84 lat/lon), and this will remain as the default if no SRS is specified. 
     150 
     151When using SRS EPSG:4326 (default), values for <limitNorth>, <limitSouth>, <limitEast> and <limitWest> should be given in decimal degrees latitude and longitude. <limitNorth> and <limitSouth> must be in the range -90.0 to +90.0, with <limitNorth> greater than <limitSouth>. <limitWest> and <limitEast> must be in the range -180.0 to 180.0 and <limitEast> should be greater than <limitWest>. Bounding boxes that span the -180 degree meridian, or the poles, are not supported. 
     152 
     153An optional <spatialOperator> may be included, populated with a term from the [#spatialOperatorList spatialOperatorList], defining the comparison to be applied to spatial coverage(s) related to metadata records. The default value is "overlaps". Note that in the discovery index database, metadata records may contain several spatial coverages, so a match can occur if any of the spatial coverages related to the metadata item match the criteria specified in the spatial search.  
    155154 
    156155=== Temporal searching : <DateRange> ===