landxml – LandXML¶
New in version 0.6.
LandXML is committed to providing an non-proprietary data standard (LandXML), driven by an consortium of partners for the inter-operability of data utilized within the Land Development industry.
The official documentation about the format is provided on the LandXML website.
LandXML is a specialized XML (eXtensible Mark-up Language) data file format containing civil engineering and survey measurement data commonly used in the Land Development and Transportation Industries.
For example:
<?xml version="1.0" encoding="utf-8"?>
<LandXML xmlns="http://www.landxml.org/schema/LandXML-1.2" time="15:49:09" date="2006-06-19" version="0" language="English" readOnly="false">
<Units>
<Metric linearUnit="meter" temperatureUnit="celsius" volumeUnit="cubicMeter" areaUnit="squareMeter" pressureUnit="milliBars" angularUnit="decimal dd.mm.ss" directionUnit="decimal dd.mm.ss">
</Metric>
</Units>
<CgPoints>
<CgPoint oID="2748159" state="existing" pntSurv="boundary" name="Q">312.04999999981374 274.33400000003166</CgPoint>
<CgPoint oID="2748179" state="existing" pntSurv="boundary" name="W">308.8430000003427 277.0350000000326</CgPoint>
<CgPoint oID="2746236" state="existing" pntSurv="boundary" name="M">306.9670000001788 19.508999999961816</CgPoint>
</CgPoints>
<Survey>
<SurveyHeader name="IS185989" headOfPower="Survey and Mapping Infrastructure Act 2003" surveyFormat="Identification" surveyPurpose="Identification" desc="Plan of Identification Survey of Lots 26 & 27 on RP726990 " type="surveyed" surveyStatus="Survey Records Only" fieldNoteFlag="false" submissionDate="2006-04-07" documentStatus="Captured">
<CoordinateSystem horizontalDatum="Local" verticalDatum="Arbitrary" />
</SurveyHeader>
<InstrumentSetup id="IS-7-IS185989" stationName="7-IS185989" instrumentHeight="0">
<InstrumentPoint pntRef="7-IS185989" />
</InstrumentSetup>
<InstrumentSetup id="IS-70-IS185989" stationName="70-IS185989" instrumentHeight="0">
<InstrumentPoint pntRef="70-IS185989" />
</InstrumentSetup>
<ObservationGroup id="OG-1">
<ReducedObservation name="3" setupID="IS-7-IS185989" targetSetupID="IS-70-IS185989" azimuth="302.504" horizDistance="10.81" distanceType="measured" azimuthType="measured" purpose="traverse" equipmentUsed="theodolite EDM" />
<ReducedObservation name="6" setupID="IS-72-IS185989" targetSetupID="IS-73-IS185989" azimuth="110.274" horizDistance="37.55" distanceType="measured" azimuthType="measured" purpose="traverse" equipmentUsed="theodolite EDM" />
<ReducedObservation name="4" setupID="IS-70-IS185989" targetSetupID="IS-71-IS185989" azimuth="359.512" horizDistance="52.12" distanceType="measured" azimuthType="measured" purpose="traverse" equipmentUsed="theodolite EDM" />
<ReducedObservation name="5" setupID="IS-71-IS185989" targetSetupID="IS-72-IS185989" azimuth="359.512" horizDistance="24.574" distanceType="measured" azimuthType="measured" purpose="traverse" equipmentUsed="theodolite EDM" />
</ObservationGroup>
</Survey>
<CoordinateSystem datum="OfPlan" desc="Vide IS185958" />
</LandXML>
LandXML structure¶
LandXML use a schema which specifies how to formally describe the elements of the document. The schema currently used is version 1.2.
Tags and attributs¶
| Tag | Attribut | Parent tag | formats.Feature |
|---|---|---|---|
| Units | |||
| Metric | Units | ||
| linearUnit | dist_unit | ||
| angularUnit | angle_unit | ||
| Imperial* | Units | ||
| Survey | |||
| SurveyHeader* | Survey | ||
| Equipment* | Survey | ||
| CgPoints | Survey | “PT” in feature | |
| CgPoint | CgPoints | formats.Point |
|
| name | CgPoints | point_name | |
| Feature | CgPoint | ||
| Property | Feature | ||
| values | attrib | ||
| InstrumentSetup | Survey | “ST” in feature | |
| id | station_id | ||
| stationName | point_name | ||
| instrumentHeight | ih | ||
| orientationAzimuth | hz0 | ||
| circleAzimuth | hz0 | ||
| Feature | InstrumentSetup | ||
| Property | Feature | ||
| values | attrib | ||
| ObservationGroup | Survey | ||
| setupID | station_id | ||
| Backsight | ObservationGroup | ||
| circle | circle | ||
| setupID | “setup” + id | ||
| BacksightPoint | ObservationGroup | ||
| name | |||
| RawObservation | ObservationGroup | “PO” in feature | |
| setupID | station_id | ||
| azimuth | azimuth | ||
| horizAngle | angle | ||
| zenithAngle | z_angle | ||
| slopeDistance | dist | ||
| horizDistance | dist | ||
| targetHeight | th | ||
| TargetPoint | RawObservation | formats.Point |
|
| desc | point_name | ||
| name | point_name | ||
| Feature | RawObservation | ||
| Property | Feature | ||
| values | attrib |
* Not implemented
Annotations¶
- Units :
- All angular and direction values default to radians unless otherwise noted. Angular values, expressed in the specified Units.angleUnit are measured counter-clockwise from east=0. Horizontal directions, expressed in the specified Units.directionUnit are measured counter-clockwise from 0 degrees = north.
- CgPoints :
- A collection of COGO points. (Cg = COGO = Cordinate Geometry).
- InstrumentSetup :
- The Instrument setup location is defined by either a coordinate text value (“north east” or “north east elev”) or a CgPoint number reference “pntRef” attribute.
- ObservationGroup :
- All observations to the same point in a group should be averaged together (they have consistant orientation).
- TargetPoint :
- Represents a 2D or 3D location for the target. It is defined by either a coordinate text value (“north east” or “north east elev”) or a CgPoint number reference “pntRef” attribute.
Known limitations¶
- Support for all tags is still incomplete, here is a list of TODO:
- add all missing tags
- add the possibility to customize code
See also