pycsw enhancement for geospatial similarity calculation

pycsw is an OGC CSW server implementation written in Python.

pycsw fully implements the OpenGIS Catalogue Service Implementation Specification (Catalogue Service for the Web). Initial development started in 2010 (more formally announced in 2011). The project is certified OGC Compliant, and is an OGC Reference Implementation. Since 2015, pycsw is an official OSGeo Project.

pycsw allows for the publishing and discovery of geospatial metadata via numerous APIs (CSW 2/CSW 3, OpenSearch, OAI-PMH, SRU). Existing repositories of geospatial metadata can also be exposed, providing a standards-based metadata and catalogue component of spatial data infrastructures.

pycsw is Open Source, released under an MIT license, and runs on all major platforms (Windows, Linux, Mac OS X).

Please read the docs at http://pycsw.org/docs for more information.

Installation

git clone https://github.com/KathHv/pycsw.git && cd pycsw
pip3 install -e . && pip3 install -r requirements-standalone.txt

Configuration for Server-Admin

Edit preferences.cfg To edit the default values of the parameters in GetSimilarRecords edit the parameters in [similarity]. For more information see the (pycsw documentation)[http://docs.pycsw.org/en/latest/configuration.html].

Run pycsw

Run in pycsw folder:

python3 pycsw/wsgi.py

What is new in our pycsw version?

We enhanced pycsw with two similarity functions that include metadata fields of the records like the wkt_geometry, the temporal extent, the vector representation and the format of the related file.

Similar records can be displayed by the 'getSimilarRecords'-request that react to the following parameters:

• id (required)
• all parameter that are included in the 'getRecordById'-request
• similarrecords ²               max number of shown similar records
• temp_weight ¹             how relevant shall the temporal factor be in the similarity calculation
• datatype_weight ¹       how relevant shall the similarity of datatypes be in the similarity calculation
• location_weight ¹        how relevant shall the location factor be in the similarity calculation
• geographic_weight ¹  how relevant shall the geographic factor be in the similarity calculation
• extent_weight ¹           how relevant shall the extent factor be in the similarity calculation

1 The range of the weights can be definded in the preferences.cfg-file as well through the 'max_value_for_weight' variable (right boundry). the default weight for each weight can be set in this file as well
2 the limit for this parameter can be set in the preferences.cfg-file through the parameter 'limit_for_similarrecords'.