GML: Support for unit of measure for radius of gml:CircleByCenterPoint does not work as expected

[heidivanparys]

What is the bug?

Setting the value of gml:Curve/gml:segments/gml:CircleByCenterPoint/gml:radius/@uom to km or [nmi_i] does not construct the expected geometry in GDAL/QGIS, although those units should be supported according to what I can see in e.g. #3118.

Steps to reproduce the issue

Use the following three GML snippets. The circle using meter as unit is shown fine. The circles using kilometer and nautical miles are not shown fine.

Note: I know that using nautical miles would not make that much sense in the given location and with the given CRS, but I would at least expect km to work here. I added the nautical miles example to test what would happen, and also because I could see in other issues that support for that uom should be present.

<?xml version="1.0" encoding="UTF-8"?>
<ex:FeatureCollection
    xmlns:gml="http://www.opengis.net/gml/3.2"
    xmlns:ex="urn:uuid:33491e0b-1e7a-4dc0-817e-2c333fa786f7"
    gml:id="id7c0d5245-cc49-4f2d-b1fa-25c9a87af4c7">
    <ex:featureMember>
        <ex:MyFeatureTypeMeters gml:id="id894572b5-3d7d-446b-8b47-6c96ec30e06a">
            <ex:id>894572b5-3d7d-446b-8b47-6c96ec30e06a</ex:id>
            <ex:geometri>
                <gml:Surface srsName="http://www.opengis.net/def/crs/EPSG/0/25832" srsDimension="2">
                    <gml:patches>
                        <gml:PolygonPatch>
                            <gml:exterior>
                                <gml:Ring>
                                    <gml:curveMember>
                                        <gml:Curve>
                                            <gml:segments>
                                                <gml:CircleByCenterPoint numArc="1">
                                                    <gml:pos>665843.66 6063914.72</gml:pos>
                                                    <gml:radius uom="m">3000</gml:radius>
                                                </gml:CircleByCenterPoint>
                                            </gml:segments>
                                        </gml:Curve>
                                    </gml:curveMember>
                                </gml:Ring>
                            </gml:exterior>
                        </gml:PolygonPatch>
                    </gml:patches>
                </gml:Surface>
            </ex:geometri>
        </ex:MyFeatureTypeMeters>
    </ex:featureMember>
</ex:FeatureCollection>

<?xml version="1.0" encoding="UTF-8"?>
<ex:FeatureCollection
    xmlns:gml="http://www.opengis.net/gml/3.2"
    xmlns:ex="urn:uuid:33491e0b-1e7a-4dc0-817e-2c333fa786f7"
    gml:id="id7c0d5245-cc49-4f2d-b1fa-25c9a87af4c7">
    <ex:featureMember>
        <ex:MyFeatureTypeKilometers gml:id="id894572b5-3d7d-446b-8b47-6c96ec30e06a">
            <ex:id>894572b5-3d7d-446b-8b47-6c96ec30e06a</ex:id>
            <ex:geometri>
                <gml:Surface srsName="http://www.opengis.net/def/crs/EPSG/0/25832" srsDimension="2">
                    <gml:patches>
                        <gml:PolygonPatch>
                            <gml:exterior>
                                <gml:Ring>
                                    <gml:curveMember>
                                        <gml:Curve>
                                            <gml:segments>
                                                <gml:CircleByCenterPoint numArc="1">
                                                    <gml:pos>665843.66 6063914.72</gml:pos>
                                                    <gml:radius uom="km">3</gml:radius>
                                                </gml:CircleByCenterPoint>
                                            </gml:segments>
                                        </gml:Curve>
                                    </gml:curveMember>
                                </gml:Ring>
                            </gml:exterior>
                        </gml:PolygonPatch>
                    </gml:patches>
                </gml:Surface>
            </ex:geometri>
        </ex:MyFeatureTypeKilometers>
    </ex:featureMember>
</ex:FeatureCollection>

<?xml version="1.0" encoding="UTF-8"?>
<ex:FeatureCollection
    xmlns:gml="http://www.opengis.net/gml/3.2"
    xmlns:ex="urn:uuid:33491e0b-1e7a-4dc0-817e-2c333fa786f7"
    gml:id="id7c0d5245-cc49-4f2d-b1fa-25c9a87af4c7">
    <ex:featureMember>
        <ex:MyFeatureTypeNauticalMiles gml:id="id894572b5-3d7d-446b-8b47-6c96ec30e06a">
            <ex:id>894572b5-3d7d-446b-8b47-6c96ec30e06a</ex:id>
            <ex:geometri>
                <gml:Surface srsName="http://www.opengis.net/def/crs/EPSG/0/25832" srsDimension="2">
                    <gml:patches>
                        <gml:PolygonPatch>
                            <gml:exterior>
                                <gml:Ring>
                                    <gml:curveMember>
                                        <gml:Curve>
                                            <gml:segments>
                                                <gml:CircleByCenterPoint numArc="1">
                                                    <gml:pos>665843.66 6063914.72</gml:pos>
                                                    <gml:radius uom="[nmi_i]">1.62</gml:radius>
                                                </gml:CircleByCenterPoint>
                                            </gml:segments>
                                        </gml:Curve>
                                    </gml:curveMember>
                                </gml:Ring>
                            </gml:exterior>
                        </gml:PolygonPatch>
                    </gml:patches>
                </gml:Surface>
            </ex:geometri>
        </ex:MyFeatureTypeNauticalMiles>
    </ex:featureMember>
</ex:FeatureCollection>

Versions and provenance

Installation via OSGEO4W.

QGIS version	3.40.0-Bratislava
QGIS code revision	b56115d874
Libraries
Qt version	5.15.13
Python version	3.12.7
GDAL/OGR version	3.9.3
PROJ version	9.5.0
EPSG Registry database version	v11.016 (2024-08-31)
GEOS version	3.13.0-CAPI-1.19.0
SQLite version	3.46.1
PDAL version	2.8.1
PostgreSQL client version	unknown
SpatiaLite version	5.1.0
QWT version	6.3.0
QScintilla2 version	2.14.1
OS version	Windows 10 Version 2009
Active Python plugins
quick_map_services	0.19.34
db_manager	0.1.20
grassprovider	2.12.99
MetaSearch	0.3.6
processing	2.12.99

Additional context

This issue is related to #11582, #4807 and #3118.

[rouault]

fix in #11599. Won't likely make it to 3.10.1 whose RC1 has been issued just before

[rouault]

Won't likely make it to 3.10.1 whose RC1 has been issued just before

actually we'll have a RC2, so the fix will go to 3.10.1

[heidivanparys]

Great, thanks a lot for the very quick reply and fix!