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 &amp; 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

Schema 1.2 for LandXML