Question

例如，如果我们在gml：

中有以下给出的边界框

<gml:Envelope> <gml:lowerCorner>42.943 -71.032</gml:lowerCorner> <gml:upperCorner>43.039 -69.856</gml:upperCorner> </gml:Envelope>

现在，对于下角，哪个值是纬度，哪个是经度。无法在在线文档中找到此信息。

由于漫游者

上述GML格式为GeoRSS

Answer 1

来自GML架构：

<complexType name="EnvelopeType">
<choice>
<sequence>
<element name="lowerCorner" type="gml:DirectPositionType"/>
<element name="upperCorner" type="gml:DirectPositionType"/>
</sequence>
<element ref="gml:pos" minOccurs="2" maxOccurs="2">
<annotation>
<appinfo>deprecated</appinfo>
</annotation>
</element>
<element ref="gml:coordinates"/>
</choice>
<attributeGroup ref="gml:SRSReferenceGroup"/>
</complexType>
<element name="Envelope" type="gml:EnvelopeType" substitutionGroup="gml:AbstractObject">
<annotation>
<documentation>
Envelope defines an extent using a pair of positions defining opposite corners in arbitrary dimensions. The first direct position is the "lower corner" (a coordinate position consisting of all the minimal ordinates for each dimension for all points within the envelope), the second one the "upper corner" (a coordinate position consisting of all the maximal ordinates for each dimension for all points within the envelope). The use of the properties "coordinates" and "pos" has been deprecated. The explicitly named properties "lowerCorner" and "upperCorner" shall be used instead.
</documentation>
</annotation>
</element>

通向SRSReference组，其中包含允许您查找轴顺序的代码以及有关坐标的单位（以及其他内容）。：

<attributeGroup name="SRSReferenceGroup">
<annotation>
<documentation>
The attribute group SRSReferenceGroup is an optional reference to the CRS used by this geometry, with optional additional information to simplify the processing of the coordinates when a more complete definition of the CRS is not needed. In general the attribute srsName points to a CRS instance of gml:AbstractCoordinateReferenceSystem. For well-known references it is not required that the CRS description exists at the location the URI points to. If no srsName attribute is given, the CRS shall be specified as part of the larger context this geometry element is part of.
</documentation>
</annotation>
<attribute name="srsName" type="anyURI"/>
<attribute name="srsDimension" type="positiveInteger"/>
<attributeGroup ref="gml:SRSInformationGroup"/>
</attributeGroup>

因此，如果没有指定的SRS，就无法回答您的问题，我们甚至不知道您的坐标是什么单位。

GML边界框中的纬度/经度信息

1 个答案: