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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