Categories of linear referencing methods per ISO 19148:2021 §6.2.3.These categories define the fundamental approach to determining positions along a linear feature:- absolute: Fixed origin, typically the first coordinate- relative: Origin at a specified referent point- interpolative: Position determined by interpolation between control points
Diagram
Type
restriction of string
Facets
enumeration
absolute
Position specified as absolute distance from a defined origin, typically the first coordinate of the LinearExtent. Per ISO 19148, absolute methods use distance from a fixed origin point.DIGGS examples:- Measured depth from kelly bushing (origin at KB)- Distance along geophysical trackline from start- Chainage along pipeline from reference monument- Distance from top of core sample
enumeration
relative
Position specified relative to a referent point along the linear feature. Per ISO 19148, relative methods express position as offset from a reference point that may not be at the origin.DIGGS examples:- Depth below ground surface (referent at ground level)- Distance from line intersection point- Offset from kickoff point in directional drilling
enumeration
interpolative
Position determined by interpolation between known control points (anchor points). Per ISO 19148, interpolative methods calculate position based on known reference points distributed along the linear element.DIGGS examples:- Core positions adjusted for stretch/compression between top and bottom- Trackline positions interpolated between GPS waypoints- Borehole positions adjusted using downhole survey stations
Source
<simpleType name="LinearReferencingMethodTypeEnum"><annotation><documentation>Categories of linear referencing methods per ISO 19148:2021 §6.2.3. These categories define the fundamental approach to determining positions along a linear feature: - absolute: Fixed origin, typically the first coordinate - relative: Origin at a specified referent point - interpolative: Position determined by interpolation between control points</documentation></annotation><restriction base="string"><enumeration value="absolute"><annotation><documentation>Position specified as absolute distance from a defined origin, typically the first coordinate of the LinearExtent. Per ISO 19148, absolute methods use distance from a fixed origin point. DIGGS examples: - Measured depth from kelly bushing (origin at KB) - Distance along geophysical trackline from start - Chainage along pipeline from reference monument - Distance from top of core sample</documentation></annotation></enumeration><enumeration value="relative"><annotation><documentation>Position specified relative to a referent point along the linear feature. Per ISO 19148, relative methods express position as offset from a reference point that may not be at the origin. DIGGS examples: - Depth below ground surface (referent at ground level) - Distance from line intersection point - Offset from kickoff point in directional drilling</documentation></annotation></enumeration><enumeration value="interpolative"><annotation><documentation>Position determined by interpolation between known control points (anchor points). Per ISO 19148, interpolative methods calculate position based on known reference points distributed along the linear element. DIGGS examples: - Core positions adjusted for stretch/compression between top and bottom - Trackline positions interpolated between GPS waypoints - Borehole positions adjusted using downhole survey stations</documentation></annotation></enumeration></restriction></simpleType>