EPICENTRE 3 EPSG project

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EPICENTRE 3 - EPSG project
Roel Nicolai senior consultant Geomatics and
GIS Shell International Exploration and
Production Technology Application and
Research Rijswijk - The Netherlands
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What is the EPSG?

• European Petroleum Survey Group
• Professional forum for chief surveyors of EP
  companies in Europe
• significant activity is exchange of geodetic
  data.
• Approached by POSC for advice on data modeling
  for Epicentre 1992
• Special Interest Group formed from main EPSG,
  consisting of geodetic experts 1993
• EPSG Geodesy Working Group
• Roger Lott - BP-Amoco (chairman)
• Jim Cain -Western Atlas
• Jean-Patrick Girbig - Petroconsultants
• Roel Nicolai - Shell International EP
• Pierre Zakia (Christian Ameil) - Elf Aquitaine

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What is EPSGs relationship with POSC?

• Advisory on geodetic modeling subjects
• geodetic ? spatial reference systems
• Coordinate System sub-model of Epicentre
• excellent co-operation of POSC data modelers
• hindered by our (EPSG) poor understanding of
  Epicentre modeling conventions
• Advisory on geodetic reference parameters
• POSC advised to include parameters in Epicentre
• coordinate systems, coordinate transformations
• after release of the first snapshots EPSG
  realized advice was needed
• oil company and contractor data put into public
  domain after extensive data reconciliation
• Epicentre standard reference data updated to
  current EPSG values only at Epicentre releases
• Advisory on coordinate transformation methods
• Guidance Note 7

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Other EPSG contacts on standards
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Other EPSG contacts on standards

• GeoTIFF
• approached POSC to use coordinate system standard
  reference data. Referred to EPSG.
• GeoTIFF v1 adopted a coordinate system data
  structure based on EPSG data distribution model
  but modified to incorporate influence of US
  metadata standard.
• EPSG data (v2) extended to include numeric codes
  for TIFF compatibility. Agreed to include data
  not necessarily required by oil industry.
• reference data not updated with subsequent EPSG
  updates.
• Open GIS Consortium
• early drafts adopted GeoTIFF work.
• EPSG data distribution model mistaken for POSC
  data model.
• referencing EPSG data.

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Other EPSG contacts on standards

• ISO TC 211
• EPSG is a class A liason contributor to the
  spatial referencing by coordinates work item.
  Contribution has focussed on having GIS user
  needs included in what otherwise would have been
  rigorous geodetic discussions.
• Current ISO draft very similar to EPSG advice to
  POSC (some terminology changes).
• OpenSpirit
• Based on Shell application integration software
  SpiritII
• included coordinate transformation software,
  after transform to OO
• parameters not included
• Shell EPSG representative accepted as adviser to
  Alliance

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EPSG Geodetic Reference Parameters

• Collecting industry wide data sets from
• oil companies
• seismic companies
• survey contractors
• national geodetic institutes
• Reconciling the differences
• Data quality only non-contentious data,
  confirmed by more than one uncorrelated source.
• Shared usage exclude data specific to one single
  company
• Practicality exclude data ostensibly only for
  geodetic usage
• Initially offered to POSC as MS-Excel files
• Publication on WWW as a FREE service, no
  liability accepted
• Petroconsultants (now HIS Energy Group)
• http//www.petroconsultants.com/products/geodetic2
  .html

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EPSG Geodetic Reference Parameters (2)

• 1996 Simple relational database
• NOT Epicentre
• seen as too complex by users
• users wanted access to tables direct
• limited MS-Access experience in EPSG-GWG
• Several upgrades to the data model
• data driven
• analysis driven
• Increasing user base
• significant feedback from customers
• data quality improved
• new data
• increasing customer base outside EP
• EPSG household name in practical geodetic
  reference parameters

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EPSG data usage
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Back to Epicentre

• Dec 1997 Review of Epicentre 2.2 beta
• Coordinate Systems and Transformations
• Several loosely connected geodetic issues
• Recommendations for changes
• Funding issues
• prevented earlier
• implementation

Shell International Exploration and production
B.V. Research and Technical Services
Siep report
December 1997
SIEP 97-5892
Review of Coordinate System
sub-model of EPICENTRE 2.2 beta and
associated geodetic aspects
by
R. Nicolai (EPT-AM) for the
European Petroleum Survey Group - Geodesy Working
Group with input from R. Lott (BP
Exploration) J. Cain (Western Geophysical) J.P.
Girbig (Petroconsultants) P. Zakia (Elf)
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Summary of recommended changes

• Simplification of the coordinate system model
• extend with Compound Coordinate System
• 3-dimensional coordinate systems
• Re-model the vertical coordinate system model
• simplify using analogy with horizontal coordinate
  systems
• Extend coordinate transformations
• extend with concatenated transformations
• include local coordinate systems in
  transformations
• some recent restructuring added
• Signal inconsistencies in Reference entities data
• e.g. ref coordinate system constraint

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EPICENTRE 2.2 - Coordinate Systems
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Some Types of Coordinate System
Local or
Geodetic
non-geodetic
Geographic 3D
Geocentric
Local 3D
3D
X Y Z
????H
i j k
2D
Projected 2D
Local 2D
Geographic 2D
(Horizontal)
i j
E N
????
Local 1D
1D
Gravity related Height
Ellipsoidal Height
k
(Vertical)
h
H
Geographic Height
Projected Height
Projected Local height
Compound
E N h
E N k
??? h
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Coordinate systems and Transformations
geocentric X,Y,Z
proper full 7-parameter datum transformation
proper full 7-parameter datum transformation
with embedded cartesian to geographical
conversion
geocentric to ellipsoidal and v.v
transformation of ellipsoidal to geoidal height
or v.v. applying a geoid model
geographic 3D ????, H
drop vertical component
simplified 7 parameter datum transformation,
assuming ellipsoidal height0 occasionally a
polynomial transformation
local 3D i, j, k
simplified 7 parameter datum transformation,
assuming ellipsoidal height0 vertical component
remains unchanged or gets offset applied
compound ????? h
geographic 2D ????
drop vertical component
drop vertical component
only specified by exception, usually as a
polynomial regresssion combining the effect of
two map projections and a datum change
Rarely encountered specifies delta-Lat and
delta-Lon as plane local coordinates implies a
Plate Carré projection
(inverse) map projection, leaving vertical
component unchanged or applying offset
(inverse) map projection
local 2D i, j
only specified by exception, see projected 2D.
Vertical component is unchanged or gets an offset
applied.
drop horizontal components
compound N, E h
projected 2D N, E
drop vertical component
affine transformation
drop horizontal components
applying offset to height/depth
applying offset to height/depth
local 1D k
vertical h (d)
applying offset to height/depth
drop horizontal components
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EPICENTRE 3 - EPSG recommendations
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The end

• Thank you for your attention

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Original EPSG data model
Horizontal
from
Geodetic
Geodetic
Coordinate
to
Transformation
Datum
System

Indicates relationship
between a projected CS
and its source geographic CS
Transformation
Path
Prime
Ellipsoid
Meridian
For projected
coord.systems
Transformation
Transformation
Polynomial
Non-Polynomial
Unit of
Measure
Length
Angle
Scale

Three separate
tables are used for
units of measure of
Transformation
length, angle and scale.
Method
The relationships shown
in this diagram are
therefore simplified
from
Vertical Offset
Vertical
Vertical
Coordinate
to
Datum
System
Regrettably often confused for Epicentre
Change
Area
Codes

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EPICENTRE 2.2 - Coordinate Systems
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EPICENTRE 3 proposed
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EPICENTRE 3 proposed
Vertical Coord System
Geocentric Coord System
Geodetic Datum
Compound Coord System
Geographic 2D Coord System
Geographic 3D Coord System
Non-spatial Coord System
Vertical Datum
Projected 2D Coord System
Local Coord System
Local Datum
Homogeneous Spatial Coordinate System (Abstract)
????
Coordinate System (Abstract)
?
Applied Transformation
Single coordinate transformation (Abstract)
Concatenated Transformation
?
Map Projection Transformation
Geodetic Transformation
Non-spatial Transformation
Coordinate transformation (Abstract)
Coord Transform Value
Coord Transform Parameter
Coord Transform Method
Transformation Path
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Unit of measure and coordinate system
Reference data example
Reference data example
coordinate system
ref. coord. system constraint
'geographic 2d'
'projected 2d'
has a set of
has a set of
predefined axis
predefined axis
ref.axis orientation
types of
types of
'latitude' and 'longitude'
'northing' and 'easting'
ref. axis type
coordinate system axis
These axes describe the
These axes describe the
following predefined quantities
following predefined quantities
'latitude' and 'longitude'
'northing ftUS' and 'easting ftUS'
ref.quantity property
These quanties are of the
These quanties are of the
following predefined types
following predefined types
'length ftUS' (2x)
Proposed new relationship
'plane angle (2x)'
ref.quantity type
These types have an
These types have only one
alternative UOMs
range
allowed range and a series
allowable 'alternative' UOMs,
of allowable 'alternative'
viz the one featuring in the
UOMs. In the case of a
name.
plane angle
No range has been defined.
ref. unit of measure
dega
rad
mina
seca
gon
gr