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Vector checks

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marketajindrova edited this page May 14, 2020 · 22 revisions

Vector checks

QC tool does not take tolerance into account during spatial relationship operations such as overlaps, gaps, touches. The aim is to make the deliveries portable across the tools without any hassle.

raster.unzip

Delivery can be unzipped

The check can not be skipped. The result values of the check are: ok, aborted.

The check verifies that the delivery has been uploaded to QC tool as a valid ZIP file and the ZIP file can be successfully unzipped.

vector.naming

Naming is in accord with specification

The check can not be skipped.

The result values of the check are: ok, aborted.

The delivery must contain all prescribed layers, see dedicated page Symbolic layer names.

If the delivery is supplied in the geodatabase format, there should be only one geodatabase in the zip file. The directory of the geodatabase may be located anywhere in the directory hierarchy, eg. all examples are valid: clc2012_mt.gdb, mt/clc2012_mt.gdb, 2012/mt/clc2012_mt.gdb. Each feature class inside the geodatabase corresponds to one layer.

If the delivery is supplied in the shapefile format, there may be multiple shapefiles in the zip file. Each shapefile corresponds to one layer. The shapefiles may be located anywhere in the directory hierarchy, eg. all examples are valid: rpz_du025a_lclu2012_v1_1.shp, du025a/rpz_du025a_lclu2012_v1_1.shp, shapefiles/rpz_du025a_lclu2012_v1_1.shp.

The naming conventions are case-insensitive, eg. both rpz_du025a_lclu2012_v1_1.shp and RPZ_DU025A_LCLU2012_v1_1.SHP are valid names.

vector.attribute

Attribute table check

objectid and fid attributes reserves special treatment. These are internal attributes operated by the tools. User is not allowed to intervene such operations. Therefore, such attributes are considered not being part of user defined attributes. Because of this, this check ignores objectid and fid.

objectid is specific to geodatabase format. objectid values are preserved throughout checks so that user can actually identify a feature by the value. Wherever fid is mentioned, it is an alias for this objectid.

Shapefile format supports no internal object identifier. However, when the feature is read from the file, a tool attaches internal fid attribute to the feature and set its value to ordinal number.

There are special attributes shape_area and shape_length. Such attributes are specific to ArcGIS tool. The tool defines them automatically and the tool even sets their values on the fly. While the attributes do really exist at user level, they are parts of user defined fields. In accord, this specification does refer such attributes.

The check verifies that particular layer defines exactly the attributes specified. There must be no missing nor extra attribute present in the layer.

The check ignores any geometry columns.

vector.epsg

CRS (Projection) check

Each layer in the delivery must have a coordinate reference system (CRS) assigned. The CRS definition must include a valid EPSG code. For geodatabase deliveries, the CRS definition and EPSG code must be specified in the feature dataset definition. For shapefile deliveries, the CRS definition must be in the .prj file and must contain an AUTHORITY clause with EPSG code.

Shapefiles created in ArcGIS do not always have the EPSG authority in the .prj file. To add a valid EPSG code to the .prj file, use GDAL software (gdal_translate or qgis).

Product specific sets of allowed EPSG codes are described below.

vector.unique

Unique attribute check

Attributes described below can contain only unique values. In addition, NULL values are not allowed.

vector.enum

Valid codes

The values representing Land use / land cover (LULC) code must belong to a pre-defined set of valid codes. Empty text or NULL values are not allowed.

vector.change

Distinct codes in change layer

The check is applicable to change layers only. Change layers are currently parts of CORINE Land Cover, Coastal Zones, Urban Atlas and Natura 2000 products.

Features having the same code in initial year and reference year are reported as errors.

Corine Land Cover products have slight difference while they take into account technical change. The feature is a member of technical change if it has chtype attribute set to T. Such features are then reported as an exception instead of an error.

vector.non_probable_changes

Non-probable changes

The check is applicable to the Urban Atlas change layer product only.

The check reports features where the class change can be found in the list of non-probable changes. Such features are reported as warning features. The check is informative and always results in ok status.

vector.singlepart

Singlepart polygon check

The QC tool does not allow multi-part geometries.

All layers in all vector products:

  • feature satisfying general requirements:
    • feature is a single-part polygon; a single-part polygon may contain holes, but may not contain multiple exterior rings.

Reference:

vector.geometry

Geometries are valid

  • feature satisfying general requirements:
  • For each feature with invalid geometry, the invalid geometry reason (i.e. self-intersection) and invalid geometry location can be found in the attachment error table.
  • NOTE: Ring self-intersections, while considered valid by ArcGIS, are also reported as errors by the QC tool.

vector.gap

There is no gap in the AOI

There must be no area inside AOI not being covered by some of the layer features. Areas inside AOI not covered by any of the features (gaps) are reported as error features created for the purpose.

vector.mmu

Minimum mapping unit

vector.max_area

Maximum mapping unit

vector.mmw

Minimum mapping width

vector.overlap

No overlapping polygons

vector.neighbour

No neighbouring polygons with the same code

vector.layer_area

Vector and raster layer area comparison

vector.inspire

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