Presentation Index

 
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1

SEDRIS Spatial Reference Model

2

SRM Tutorial

3

Outline

4

Section I

5

In the Beginning ...

6

Simulation Interfaces

7

A Spectrum of Constructive, Live and Virtual Capabilities Support Training, Planning & Analysis

8

A Spectrum of Constructive, Live and Virtual Capabilities Support Training, Planning & Analysis

9

The Interface Canyons

10

Real Operational Systems

11

Why is a Spatial Reference Model (SRM) Needed?

12

SRM Requirements

13

Location is Not Enough

14

A Shared Solution is Required!

15

Structure of the SRM ISO Standard

16

Structure of the SRM ISO Standard

17

Section II

18

It’s a Loooong Way Up

19

Here’s an Interesting Perspective

20

Not All Projections are Geodetic!

21

More Familiar?

22

Spatial, the Final Frontier

23

So How Will We Get There?

24

Coordinates

25

Coordinate System Types

26

Depictions of 2D Rectilinear Coordinate Systems

27

Curvilinear Coordinate Systems

28

Time – the fourth dimension

29

Systems of Time

30

Locating a Coordinate System

31

Defining an ORM

32

Defining an ORS

33

Ellipsoid of Revolution

34

Standard Spheres

35

Standard Ellipsoids of Revolution

36

Equipotential Surfaces

37

Gravity Equipotential Reference Surfaces

38

Pressure Equipotential Reference Surfaces

39

Earth Reference Surfaces

40

Standard Horizontal Datums

41

Local Horizontal Datums

42

Relating Multiple Earth-related Surfaces

43

ORM Types (1 of 3)

44

ORM Types (2 of 3)

45

ORM Types (3 of 3)

46

Defining a SRF

47

SRF Example

48

Et Voilá: A Celestiocentric SRF

49

SRFs by Category

50

Many SRF Realizations

51

Spatial Operations

52

Operations on Coordinates

53

Types of Operation Errors

54

Spatial Reference Model

55

Section IIB

56

Ellipsoid of Revolution Geometry & Notation

57

Latitude, Longitude and Height

58

Earth Surface Relationships

59

Earth’s Gravitational Field

60

SRM Refresher

61

Section III

62

Development of Surfaces to Generate Maps

63

Map Projections

64

Projecting from 2D to 1D

65

Cylindrical Projections

66

Planar Projections

67

A Stereographic Projection

68

Conic Projections

69

Mercator Projection

70

Oblique Mercator Projection*

71

The Grid For Transverse Mercator*

72

Universal Transverse Mercator (60)

73

Lines of Constant Heading*

74

Great Circle Arc between Moscow and Washington D.C.*

75

Many Map Projections are Conformal

76

Section IV

77

Augmented Projection-Based SRFs

78

“3D” Projection-based SRFs

79

Coordinate Operations affect Geometrical Relationships

80

SRF Operation Relationships

81

Geometric Distortions

82

Distance and Elevation Angle

83

Distance Distortion Can Be Mitigated, Somewhat

84

Azimuth

85

How Much Azimuth Distortion?

86

Augmented UTM (AUTM) example:

87

Section V

88

Modelers Often Prefer Orthonormal Coordinate Systems

89

Geometry Distorting 3-D SRFs are often Used – Why ?

90

Relationships Between SRFs and Simulations

91

MCG&I and Dynamics Modeling

92

MCG&I

93

Dynamics Modeling

94

Section VI

95

Euclidean Distance for an Orthonormal System

96

Defining Geometrical Concepts

97

The Traditional Surveying Process

98

Surveying is a Complex Process

99

Traditional Distance Determination in Surveys

100

Surveying on a Plane ERS

101

Surveying on a Plane ERS with a Topographic Surface Added

102

Surveying on a Spherical ERS

103

Chaining on a Spherical ERS with a Topographic Surface Added

104

Surveying on an Ellipsoid of Revolution ERS

105

Normal Section of an Ellipsoid of Revolution ORS

106

Distance on an Ellipsoid of Revolution ORS

107

Bearing Angles (Ellipsoid of Revolution ORS)

108

Bearing when a Point P is above the Ellipsoid of Revolution ORS

109

Once the Environment is Included, There are Many Feasible Paths

110

Placing a Solid Cube on an ORS

111

Doing the Math ...

112

Placing a Cube on a Topographic Surface

113

Long Linear Structures

114

Vectors in Augmented Projection-based SRFs

115

Vectors in a Curvilinear System

116

Defining a Canonical Local Tangent Plane SRF

117

A LTP Coordinate System Embedded in a Celestiodetic SRF

118

Defining a CLTP Embedded in a Celestiodetic SRF

119

Reference Vectors

120

Reference Vector Transformations

121

SRF “North” may not be True North

122

Convergence of the Meridian

123

Representing a Projection-based SRF Vector in Terms of a CLTP

124

Computing COM For TM

125

Computing the Sine and Cosine of the COM for the Rotation Matrix

126

Observations

127

Section VII

128

Why is Accuracy Needed for Coordinate Operations?

129

Shooting at a Target in the Real World

130

Simulation of Shooting at a Target

131

Error Sources in Coordinate Operations Software

132

Definition of Error

133

Numerical methods

134

Analytic (closed form) Solutions

135

Taylor/Maclaurin Series Methods

136

Iterative Methods

137

Error in Power Series Expansions

138

Authoritative Sources Sometimes Appear to Disagree

139

Direct Approximation of a Function or Its Inverse

140

Direct Approximation of a Function or Its Inverse (cont)

141

Error Analysis and Resolution of Disagreements

142

Effect of Small Errors

143

Fuzzy Creep/Coordinate Drift

144

Bounds Checking

145

What to Do?

146

Distortion and Computation Error Tradeoff

147

Distortion in Projection-based SRFs

148

Distortion-Accuracy Trades for UTM

149

Point Scale Equations

150

UTM Point Scale Equations

151

Linear Distortion Error For UTM

152

Difference between SR-7 & Extended Formulas for Transverse Mercator

153

Conclusions of Experiment

154

The Chaining Problem

155

Section VIII

156

SRFs

157

DRM <Location> (Page 15)

158

SRFs Supported

159

SRFs with CS Origin Offsets*

160

Local Space Rectangular

161

Local Space Rectangular (2D)

162

Geocentric

163

Geodetic

164

Geodetic (2D)

165

Local Tangent Plane

166

Local Tangent Plane (2D)

167

GCS

168

Mercator

169

Augmented Mercator

170

Oblique Mercator

171

Augm. Oblique Mercator

172

Transverse Mercator

173

Augm. Transverse Mercator

174

Universal Transverse Mercator

175

Augm. Univ. Transverse Mercator

176

Lambert Conformal Conic

177

Augm. Lambert Conformal Conic

178

Polar Stereographic

179

Augm. Polar Stereographic

180

Universal Polar Stereographic

181

Augm. Univ. Polar Stereographic

182

Equidistant Cylindrical

183

Augm. Equidistant Cylindrical

184

Geocentric Equatorial Inertial

185

Geomagnetic

186

Geocentric Solar Ecliptic

187

Geocentric Solar Magnetic

188

Solar Magnetic

189

Section IX

190

PPT Slide

191

ERS “Datum” Transformations

192

Init WGS84 Geoidal Separation

193

Get WGS84 Geoidal Separation

194

PPT Slide

195

Types of Operation Errors

196

“Valid” Coordinates

197

Coordinate Validity

198

Implementation Details (1 of 2)

199

Implementation Details (2 of 2)

200

Range Extension (1 of 2)

201

Range Extension (2 of 2)

202

PPT Slide

203

Op Support

204

Coordinate Operation Chains

205

Status Codes (1 of 3)

206

Status Codes (2 of 3)

207

Interface Specification(s)

208

Status Codes (3 of 3)

209

Operation Setup

210

Conversion Operation

211

Multi-conversion Operation

212

Boundary Checking

213

Operation Teardown

214

Vector Operation

215

Matrix Operation*

216

Transformation Operation

217

Convergence of Meridian Operation

218

"SRM Check Utility"*

219

Further Reading

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