Spatial Quality and Anomalies Diagnosis (SQUAD) Tool for QGIS Quick Start Guide


PDF document icon tl-18-06.pdf — PDF document, 419 kB (429,914 bytes)

Author(s): MEASURE Evaluation

Year: 2018

Spatial Quality and Anomalies Diagnosis (SQUAD) Tool for QGIS Quick Start Guide Abstract:

QGIS is a free and open-source geographic information system (GIS) software. The Spatial Quality and Anomalies Diagnosis (SQUAD) tool is a QGIS plug-in that will assess data quality of large spatial data sets. Because it can be difficult to perform data quality checks on large data sets, the SQUAD tool rapidly and automatically looks for anomalies in the data that may indicate data quality issues.
The tool requires two data sets (in the form of shapefiles): one consisting of point locations and the other consisting of polygons that represent administrative units. The tool will review the point locations and identify one of six anomalies:

  1. Missing coordinates
  2. Truncated coordinates (lack of adequate precision)
  3. Duplicate coordinates for distinct records
  4. Duplicate key attributes (two identical names, but plotting in different locations)
  5. Coordinate not located exactly where it would be expected (but falling within two kilometers of a border)
  6. Coordinate not located anywhere near where expected

The quick start guide provides a general overview of the use of the tool with the sample data available for the tool. A more detailed overview is available on the MEASURE Evaluation web site, here: www.measureevaluation.org/resources/tools/geographic-information-systems/squad-tool/.

Requires sample data file.

Filed under: GIS , Geographic Information Systems , Data , Spatial data