LOCA: Location Details

  • Class: Samples, Amalgamated Specimens and Laboratory Test Scheduling
Heading Unit Type Example Description
LOCA_ID   ID 327-16A Location identifier
LOCA_TYPE   PA CP+RC Type of activity
LOCA_STAT   PA PRELIM Status of information relating to this position
LOCA_NATE m 2DP 523145 National Grid Easting of location or start of traverse
LOCA_NATN m 2DP 178456.12 National Grid Northing of location or start of traverse
LOCA_GREF   PA OSGB National grid referencing system used
LOCA_GL m 2DP 16.23 Ground level relative to datum of location or start of traverse
LOCA_REM   X   General remarks
LOCA_FDEP m 2DP 32.6 Final depth
LOCA_STAR yyyy-mm-dd DT 18/03/1991 Date of start of activity
LOCA_PURP   X Groundwater observation well Purpose of activity at this location
LOCA_TERM   X Abandoned on engineer’s instruction Reason for activity termination
LOCA_ENDD yyyy-mm-dd DT 22/03/1991 End date of activity
LOCA_LETT   X TQ231784 OSGB letter grid reference
LOCA_LOCX m 2DP 565.23 Local grid x co-ordinate or start of traverse
LOCA_LOCY m 2DP 421.12 Local grid y co-ordinate or start of traverse
LOCA_LOCZ m 2DP 106.63 Level or start of traverse to local datum
LOCA_LREF   X London grid 1 Local grid referencing system used
LOCA_DATM   X Anytown datum Local datum referencing system used
LOCA_ETRV m 2DP 523195.12 National Grid Easting of end of traverse
LOCA_NTRV m 2DP 178486.12 National Grid Northing of end of traverse
LOCA_LTRV m 2DP 9.67 Ground level relative to datum of end of traverse
LOCA_XTRL m 2DP 523195.12 Local grid easting of end of traverse
LOCA_YTRL m 2DP 178486.12 Local grid northing of end of traverse
LOCA_ZTRL m 2DP 9.67 Local elevation of end of traverse
LOCA_LAT   DMS 28:52. Latitude of location or start of traverse
LOCA_LON   DMS 10:34. Longitude of location or start of traverse
LOCA_ELAT   DMS 28:53. Latitude of end of traverse
LOCA_ELON   DMS 10:34. Longitude of end of traverse
LOCA_LLZ   X WSG84 Projection Format
LOCA_LOCM   X dGPS Method of location
LOCA_LOCA   X Sub-station 1 Site location sub division (within project) code or description
LOCA_CLST   X Phase 2a Investigation phase grouping code or description
LOCA_ALID   X Tunnel Alignment P Alignment Identifier
LOCA_OFFS   2DP 10.35 Offset
LOCA_CNGE   X 500+123.23 Chainage
LOCA_TRAN   X Coordinate transforms document ref 100-23-A, dated 16 April 2010 Reference to or details of algorithm used to calculate local grid reference, local ground levels or chainage
FILE_FSET   X FS2 Associated file reference (eg boring or pitting instructions, location photographs)

Notes - 8

  • LOCA is used to transfer the spatial location of all positions where data has been recorded. This includes the location of exploratory holes, sampling points or other locations where an observation / test has been made, or a sample / measurement taken.
  • The LOCA_TYPE code is used to categorise the type of activity that has occurred at the location.
  • The details of exploratory hole construction are contained in the HDPH group. If LOCA_TYPE codes are used that represent the type of exploratory hole construction then they must be correlated with the code or combinations of codes in HDPH_TYPE. Alternatively the code ‘EH’ could be used to represent an Exploratory Hole the details of which are contained in HDPH.
  • If the AGS data file includes information on construction items, then LOCA would also include references to these locations.
  • LOCA_ID must be unique for the project and should be unique for the site to allow for consolidation of data. Consideration of this needs to be made at the outset of the project. Typically the consulting engineer or designer allows for this in specifying hole or location identifiers.
  • LOCA_FDEP will generally be null for location points other than exploratory holes, pits, piles or other below ground constructed elements.
  • Two headings, LOCA_LOCA and LOCA_CLST, provide a heading for tags of hole groupings. These groupings would typically be specified by the Investigation Supervisor/Designer rather than the GI Contractor. LOCA_LOCA is to be used to define the grouping of a hole by site location, whereas LOCA_CLST is typically used to indicate investigation phase. If codes are used to define these location or phase data, then the codes must be defined in the ABBR group.
  • LOCA_OFFS, LOCA_CNGE and LOCA_ALID allow location data to be presented by chainage and offset to an alignment as typically used for location on road and rail projects. The data included in these headings will probably be expressed in project related units. For example, offset can be defined as positive or negative (eg or -12). Chainage on UK railway projects may well be expressed in miles and chains (eg 10 mi 1 ch)