Gisheo Catalog

About

The goal of the Gisheo Data Catalog (GDIS) is to maintain an indexed repository of the available geographical data.

Availability

The catalog is accessible as a web service at:

  1. SOAP: http://nyx.info.uvt.ro/gdis/soap/query/.wsdl
  2. JSON: http://nyx.info.uvt.ro/gdis/json/

The method of interest is:

search(String query)

The query string a string conforming to CatalogQueryString?

JSON Interface

The JSON interface is identical to the SOAP interface with the main difference that the results are encoded as pure JSON objects. The GDIS Methods are invoked directly in a HTTP GET request. The input parameters required by the method should be encoded as JSON Objects (Strings, Dictionary's, etc) and are automatically decoded server-side into native object.

An example of a JSON call of the search method would be:

http://nyx.info.uvt.ro/gdis/json/search?_=a&callback=foo&query=%22vendor%3AUVT%22

Search Filters

The data catalog and his corresponding web page implement a simple data query language.

The language is similar to the filter languages used by mainstream search engines. The general syntax is

filter1:filter_value1 filter2:filter_value2

The implicit logical operation between filter specifications is AND

Available Filters

Location Based

  1. place filter: The place filter provides geo-location coordinates based on the provided place name. The syntax of place name is "city/state/country". Failure to find the location results in 0 matches.
    place:"Timisoara/Timis/Romania"
    
  1. point filter: This filter enforces that result datasets interact with a point. The syntax of point value is (lat, lon)
    point:(45.756001,21.238001)
    
  1. bbox filter: This filter enforces that result datasets interact with a bbox.
    bbox:(16.513047916844, 0, 16.5130837385849, 3.60631631377637e-05)
    

Vendor based

  1. vendor filter
    vendor:"UVT"
    

Group/Collection based

  1. Group Filter (datagroup or 'group' statements).
    group:"/Imagery/Landsat"
    

Note that the parameters required for the group and datagroup statements require and hierarchical path

ID Based

In order to retrieve an dataset description the uuid filter can be used:

uuid:ca69d2a5-49fa-4637-a471-b7f2cbcb77a3

Type Based

Data type based search is implemented using the "is" and "type" operators.

The "is" operator matches all datasets that are of the specified type (including derived types)

is:"gisheo.raster"

The previous example matches also data with the gisheo.raster.etm type.

The "type" filter is similar to the previous example but it only matches the exact data type

type:"gisheo.raster"

Logical Operators

AND

(place:"Timisoara/Timis/Romania" and place:"Lugoj/Timis/Romania")

OR

(place:"Timisoara/Timis/Romania" or place:"Lugoj/Timis/Romania")