Arizona Geographic Information Council 2002 AGIC Conference

About This Presentation

Title:

Arizona Geographic Information Council 2002 AGIC Conference

Description:

Arizona Geographic Information Council 2002 AGIC Conference – PowerPoint PPT presentation

Number of Views:127

Avg rating:3.0/5.0

Slides: 130

Provided by: davem90

Category:

more less

Transcript and Presenter's Notes

Title: Arizona Geographic Information Council 2002 AGIC Conference

1
Arizona Geographic Information Council2002 AGIC
Conference
GIS without Geodesy is a FELONY!!
Dave Minkel, National Geodetic Survey NGS
Geodetic Advisor for Arizona Dave.Minkel_at_noaa.gov,
(602) 542-1569
2
Workshop Outline

Datums
Earth Model (a.k.a. Ellipsoid)
Horizontal Datums
Vertical Datums
Projections
Geodetic control
Transformations
Public Land Survey System (PLSS)
And (If theres time left)
GPS Data Services from NGS
GPS Update
Future of the geodetic network

3
The National Geodetic Survey- a brief overview -

Formed in 1807 by President Jefferson
Survey of the Coast (1807 - 1878)
US Coast Geodetic Survey (1878 - 1970)
Geodesy is the applied science that deals with
the size and shape of the earth.
Responsible for the establishment and maintenance
of the National Spatial Reference System (NSRS)
Geodetic Advisor program puts an NGS geodesist in
cooperating States

4
ACRONYMS US
R
NAD 27
ITRF 97
GRS 80
WGS 84
NAVD 88
EGM 96
GEOID 99
NGVD 29
NAD 83
GEOID 96
5
DATUMS

A set of constants specifying the coordinate
system used for geodetic control, i.e., for
calculating coordinates of points on the Earth.
Specific geodetic datums are usually given
distinctive names. (e.g., North American Datum of
1983, European Datum of 1950, National Geodetic
Vertical Datum of 1929)

6
HORIZONTAL DATUMS

8 Constants
3 specify the location of the origin of the
coordinate system.
3 specify the orientation of the coordinate
system.
2 specify the dimensions of the reference
ellipsoid

7
VERTICAL DATUMS

A set of fundamental elevations to which other
elevations are referred.

8
Ellipsoid of RevolutionMathematical Model of the
Earth
N
b
a
S
a Semi major axis b Semi minor axis f
a-b Flattening a
9
UNITED STATESELLIPSOID DEFINITIONS
BESSEL 1841 a 6,377,397.155 m 1/f
299.1528128
CLARKE 1866 a 6,378,206.4 m 1/f
294.97869821
GEODETIC REFERENCE SYSTEM 1980 - (GRS 80) a
6,378,137 m 1/f 298.257222101
WORLD GEODETIC SYSTEM 1984 - (WGS 84) a
6,378,137 m 1/f 298.257223563
10
HORIZONTAL DATUMS

BESSEL 1841 -------------- LOCAL ASTRO DATUMS
(1816-1879)
NEW ENGLAND DATUM (1879-1901)
U.S. STANDARD DATUM (1901-1913)
NORTH AMERICAN DATUM (1913-1927)
NORTH AMERICAN DATUM OF 1927
OLD
HAWAIIAN DATUM
CLARKE 1866 PUERTO RICO DATUM
ST. GEORGE ISLAND - ALASKA
ST. LAWRENCE ISLAND - ALASKA
ST. PAUL ISLAND - ALASKA
AMERICAN SAMOA 1962
GUAM 1963
GRS80 ----------- NORTH AMERICAN DATUM OF
1983
(As of June 14, 1989)

11
THE GEOID AND TWO ELLIPSOIDS

CLARKE 1866
GRS80 or WGS84
North America
Earth Mass Center
Approximately 236 meters
GEOID
12
3D Coordinate System (NAD 83 WGS 84)Geodetic
(Geographic) Coordinates
GRS80 or WGS84 Ellipsoid

Point (F,?)
Earth Mass Center
Latitude (F)
Semi-Minor Axis
Semi-Major Axis
Prime Meridian (Greenwich, England) 0o Longitude
Equator
Longitude (?)
13
3D Coordinate Systems (NAD 83, ITRF, WGS
84)Earth-Centered Earth-fixed (ECEF)
Z Axis (parallel to axis of rotation)

Point in Arizona (-X1, -Y1, Z)
GRS80-WGS84
Z1
Point (X1, Y1, Z1)
Z1
-Y1
Earth Mass Center
Y1
Y Axis (270o W)
-X1
X1
GEOID
X Axis (Prime Meridian)
14
COMPARISON OF DATUM ELEMENTS

NAD 27 NAD 83
ELLIPSOID CLARKE 1866 GRS80
a 6,378,206.4 m
a 6,378,137. M
1/f 294.9786982
1/f 298.257222101
DATUM POINT Triangulation
Station
NONE
MEADES RANCH, KANSAS EARTH MASS
CENTER
ADJUSTMENT 25k
STATIONS 250k STATIONS
Several Hundred Base Lines
Appox. 30k EDMI Base Lines
Several Hundred Astro Azimuths
5k Astro Azimuths
Doppler Point Positions
VLBI Vectors
BEST FITTING North
America
World-Wide

15
NAD 27 and NAD 83
Can you say Metadata?
16
NAD83 is properly called NAD83 (1986) or NAD83
(86). In Arizona, NAD83 (HPGN), which is
ESRI-speak, is actually NAD83 (1992). The date
will change with the state whose data you are
looking at (e.g. UTAHs NAD83 (HPGN) is NAD83
(1994). NAD83 tells you the datum of the
coordinates, and the date tells you the year of
the adjustment (the coordinate set). Beginning
in 2005, NGS will readjust all GPS stations in
the network. At the end of that effort all
stations will be NAD83 (NSRS) or something
similar.
17
ITRF

International Terrestrial Reference Frame
Defined by International Earth Rotation Service
(late 1980s)
Uses GRS80 Ellipsoid
Has an epoch tag (ITRF88, ITRF03, etc.)
508 stations in 290 globally distributed sites
GPS, VLBI, SLR, LLR, and DORIS
Station velocities due to crustal motion are
included
Basis of all modern, high-accuracy networks
Approximately (few centimeters) the same as WGS84

18
WORLD GEODETIC SYSTEM 1984TR8350.2 World
Geodetic System 1984 - Its Definition
andRelationships with Local Geodetic
Systems(http//www.nima.mil/GandG/pubs.html)
DATUM WGS 84 RELEASED - SEPTEMBER 1987 BASED ON
OBSERVATIONS AT MORE THAN 1900 DOPPLER STATIONS
DATUM WGS 84(G730) 5 USAF GPS Tracking
Stations 5 DMA Evaluation Stations Datum
redefined with respect to the International
Terrestrial Reference Frame of 1992 (ITRF92) /-
20 cm in each component (Proceedings of the ION
GPS-94 pgs 285-292)
DATUM WGS 84(G873) 5 USAF GPS Tracking
Stations 7 NIMA Evaluation Stations Datum
redefined with respect to the International
Terrestrial Reference Frame of 1994 (ITRF94) /-
10 cm in each component (Proceedings of the ION
GPS-97 pgs 841-850)
19
I NEED TO TRANSFORMBETWEEN WGS 84 AND NAD 83
Federal Register Notice Vol. 60, No. 157, August
15, 1995, pg. 42146 Use of NAD 83/WGS 84 Datum
Tag on Mapping Products
20
MY SOFTWARE SAYS IM WORKING IN WGS-84
Unless you doing autonomous positioning (point
positioning /- 6-10 meters) youre probably NOT
in WGS-84
Project tied to WGS-84 control points obtained
from the Defense Department -- Good Luck!
Youre really working in the same reference frame
as your control points -- NAD 83?
21
ELLIPSOID - GEOID RELATIONSHIP
H Orthometric Height / Elevation (NAVD 88)

h Ellipsoidal Height (NAD 83)
GPS gives you this, not elevation.
N Geoid Height (GEOID 03)

H h - N
H
TOPOGRAPHIC SURFACE
h
N
GEOID03
Geoid
Ellipsoid GRS80
22
VERTICAL DATUMS

MEAN SEA LEVEL DATUM OF 1929
NATIONAL GEODETIC VERTICAL DATUM OF 1929
NGVD 29
(As of July 2, 1973)
NORTH AMERICAN VERTICAL DATUM OF 1988
NAVD 88
(As of June 24, 1993)

23
COMPARISON OF VERTICAL DATUM ELEMENTS

NGVD 29
NAVD 88
DATUM DEFINITION 26 TIDE GAUGES
FATHERS POINT/RIMOUSKI
IN THE U.S. CANADA
QUEBEC, CANADA
BENCH MARKS 100,000
450,000
LEVELING (Km)
102,724
1,001,500
GEOID FITTING Distorted to Fit
MSL Gauges Best Continental
Model

24
NGVD 29 and NAVD 88
Can you say Metadata?
25
VERTCON (NGVD29 lt-gt NAVD 88)

Similar to NADCON in operation
Uses gridded data set
Available as PC program or on-line (Geodetic Tool
Kit)
PC version allows file input
Based on 381,833 datum differences
Only for CONUS (48 conterminous)
Accurate to approx. 4 cm (2 sigma)
Does NOT replace differential leveling

26
Projections
Arizona Geographic Information Council2002 AGIC
Conference
27
Projections

Geodesy is surveying when you cant pretend the
earth is flat J. Ross Mackay, NGS State Advisor,
KY
Conversely, a projection is an attempt to
represent points on the curved surface of the
Earth, as defined by a datum, on a flat sheet of
paper (or a monitor). A projections mapping
equations are used to transform the 3-D positions
(Lat., Long., Height) to 2-D positions (X,Y).

28
TANGENT PLANE COORDINATE SYSTEM
Tangent Plane Single Point of Contact
29
LAMBERT CONFROMAL CONICWITH 2 STANDARD PARALLELS
Grid Scale Factor
SCALE gt 1
Nn
SCALE EXACT
STANDARD PARALLELS
SCALE lt 1
Ns
SCALE EXACT
SCALE gt 1
80
CENTRAL MERIDIAN
30
TRANSVERSE MERCATOR
SCALE lt 1
SCALE gt 1
SCALE EXACT
SCALE EXACT
SCALE gt 1
80
CENTRAL MERIDIAN
31
PLANE COORDINATE SYSTEMS

STATE PLANE AND UNIVERSIAL TRANSVERSE MERCATOR
GRID COORDINATES ARE A DIRECT MATHEMATICAL
CONVERSION FROM LATITUDE AND LONGITUDE TO A
CARTESIAN NORTHING AND EASTING (Y X) COORDINATE
SYSTEM, AND MUST MAINTAIN THE SAME DATUM TAG
e.g. NAD 83(1996) AS THE LATITUDE AND LONGITUDE

NATIONAL OCEAN SERVICE
32
UNIVERSAL TRANSVERSE MERCATOR (UTM)

http//www.nima.mil/GandG/pubs.html
The Universal Grids Universal Transverse
Mercator (UTM) and Universal
Polar Stereographic (UPS) - TM8358.2
Transverse Mercator Projection
Zones 6o Longitude World-Wide
Northing Origin (0 meters- Northern Hemisphere)
at the Equator
Easting Origin (500,000 meters) at Central
Meridian of Each Zone
NAD 27 and NAD 83 both defined in meters
NAD 27 to NAD 83 shift 200-225 meters for U.S.

NATIONAL OCEAN SERVICE
33
US National Grid (USNG)

Grid Zone Designation - The U.S. is divided
into 6-degree longitudinal zones designated by a
number and 8-degree latitudinal bands designated
by a letter. Each area is given a unique
alpha-numeric Grid Zone Designator (GZD) (i.e.
18S).
Each GZD 6x8 degree area is covered by a
specific scheme of 100,000-meter squares where
each square is identified by two unique letters.
(i.e. 18SUJ - Identifies a specific 100,000-meter
square in the specified GZD).
A point position within the 100,000-meter
square shall be given by the UTM grid coordinates
in terms of its Easting (E) and Northing (N). An
equal number of digits shall be used for E and N
the reading shall be from left with Easting first
and then Northing.
18SUJ2306 - Locates a point with a precision of 1
km
18SUJ2348306479 - Locates a point with a
precision of 1 meter

NATIONAL OCEAN SERVICE
34
STATE PLANE COORDINATE SYSTEMS

NOAA Manual NOS NGS - 5 State Plane Coordinate
System of 1983 http//www.ngs.noaa.gov/PUBS_LIB/M
anualNOSNGS5.pdf
Lambert Conformal Conic and Transverse Mercator
Projections
International, State and County Boundaries
NAD 27 - Coordinates in U.S. Survey Feet
NAD 83 - Coordinates Metric w/State Defined Foot
Conversion
1 Meter 3.280833333 U.S. Survey Feet
1 Meter 3.280839895 International Feet
NAD 27 to NAD 83 VERY large Positional Shifts
(approx. 37.9 miles westerly in Arizona)

AZs SPC is a Transverse Mercator projection
Zones defined by county lines
Same zones as NAD 27
Designed to maintain 110,000
AZ W is 115,000
NAD 83 AZ SPC uses International Foot
NAD 27 used US Survey Foot
Cannot tell foot unit by inspection
Only 7 states use International Foot
NAD 27 NAD 83 SP coordinates are
significantly different on purpose
Easting is much larger
The relationship between all SPC systems is
rigorously defined (you can get there from here)

36
111o 10' W
Origin 31o 00 N, 110o 10 W N 0.0 m, E
213,360.0 m
Central Meridian
37
Central Meridian
111o 55 W
Origin 31o 00 N 111o 55 W N 0.0 m, E 213,
360.0 m
38
Origin 31o 00 N 113o 45 W N 0.0 m E
213,360.0 m
Central Meridian
113o 45 W
Ramsey
39
COORDINATE CHANGES(STATE PLANE)

STATION RAMSEY
ARIZONA STATE PLANE COORDINATES (NAD 27/NAD 83
(92))
Northing Easting
Converg Angle Scale Factor
(NAD 27) 969,877.379 ft. 423,771.616
ft. -0o 08 18.4 0.999939945
(NAD 83) 295,628.663 m. 190,126.060 m.
-0o 08 20.0 0.99993999
(969,908.37 ft) (623,771.92
ft)
(969,910.31 ft) (623,773.16
ft)
(1.94)
(1.24)
Converted using U.S. Survey
Foot, 1 M 3.2808333333 Ft.
Converted using International
Foot, 1 M 3.2808398501 Ft.

40
STATUS OF NAD 27 AND NAD 83 STATE PLANE
COORDINATE LEGISLATION - APRIL, 2000

NO SPCS EXISTING NAD 27
ENACTED NAD 83 SPC LEGISLATION LEGISLATION
LEGISLATION
(4) (3)

(45)
District of Columbia Alabama
Alaska Maryland (S)
Oklahoma (S)
Hawaii Arkansas Arizona
(I) Massachusetts (S) Oregon (I)
Nebraska Illinois
California (S) Michigan (I)
Pennsylvania (S)
Puerto Rico Colorado
(S) Minnesota Rhode Island
Connecticut
(S) Mississippi (S) South Carolina
(I)
I International Feet and Meters
Delaware(S) Missouri
South Dakota
1 m 3.280839895 feet Florida (S)
Montana (I) Tennessee (S)
S U.S. Survey Feet and Meters Georgia (S)
Nevada Texas (S)
1 m 3.280833333 feet
Idaho (S) New
Hampshire Utah (I)
Indiana (S) New
Jersey Vermont
Iowa New Mexico (S)
Virginia (S)
Kansas New York (S)
Washington (S)
Kentucky (S) North Carolina (S)
West Virginia
Louisiana North Dakota (I)
Wisconsin (S)
Maine Ohio
Wyoming

41
Datums Projections used in Arizona
Survey Data courtesy of Tom Elder, City of Phoenix
42
GROUND LEVEL COORDINATES

I want State Plane Coordinates at ground.
Ground level coordinates are NOT State Plane
Coordinates!!!!! SPCs are defined on the
ellipsoid, not at ground.

43
GROUND LEVEL COORDINATES
Distance (Grid) ? Distance (Ground)
Ground
Ellipsoid Height
Grid
44
GROUND LEVEL COORDINATESPROBLEMS

PROJECTS DIFFICULT TO TIE TOGETHER
CONFUSION OF COORDINATE SYSTEMS
LACK OF DOCUMENTATION

45
Ground Level Coordinate Problem(s)

46
GROUND LEVEL COORDINATESHow do I fix them?

Surveyor (data source) must provide explicit
description of how ground coordinates were
determined METADATA !!
Divide the ground coordinates by the combined
factor
Combined factor scale factor X elevation factor
Scale factor (combination of point scale factors)
Elevation factor (20,906,000)/(20,906,000 H
N)
20,960,000 m Mean earth radius
H Orthometric Height (a.k.a. Elevation)
N Geoid Height (Geoid 03)
A common method to bring ground coordinates to
grid, but not necessarily the right method
Regionalized combined factor
City of Scottsdale
Explicitly specify the method of
projection/conversion in contracts
No Metadata No Hope (almost)

47
GROUND LEVEL COORDINATESWhy would I want them?

Flagstaff, AZ (Flagstaff NCMN)
Elevation 2168 m, Geoid Height -23 m
Scale factor 0.99990812
Elevation Factor 0.999897408
Combined Factor 0.999805537
Distortion
In ppm Combined factor 1 195 ppm
Proportional 15128
2000 m (grid) 2000.4 (ground)
5280 ft (grid) 5281.03 ft (ground)

48
Metadata for Positions/Coordinates

METADATA IS DATA ABOUT DATA
DATUM
NAD 27, NAD 83(1986), NAD 83 (199X), NGVD29,
NAVD88
UNITS
Meters, U.S. Survey Feet, International Feet,
Chains, Rods, Pole
ACCURACY
A, B, 1st, 2nd, 3rd, 3cm, Scaled
SOURCE
Surveyor, Engineer, Digitized, Scanned
Who dun it?

49
METADATA??
Horizontal Datum??
Plane Coordinate Zone ??
Units of Measure ??
How Accurate ??
50
An example of good Metadata everything is stated
AND its clear and explicit! This information is
found in the legend for the drawings associated
with the project.
51
Low DistortionProjections
Arizona Geographic Information Council2002 AGIC
Conference
52
A method for reducingmap projection distortion
in areas of significant topographic
relief(Presented at 2003 ACSM Annual
Conference)

Michael L. Dennis, P.E.
Shephard-Wesnitzer, Inc.
Western Australian Centre for Geodesy
Curtin University of Technology

53
Linear distortion at the ground

Ratio of infinitesimal grid and ground lengths
at a point
Same in all directions for conformal projections
Linear distortion, d, at a point on the ground
is computed here as
where
k projection grid scale factor (w/respect to
ellipsoid)
h height of point above ellipsoid
R ellipsoid radius
Distortion expressed here in parts per million
(ppm)

Source Michael Dennis, PE Shepard Wesnitzer
Inc.
54
Cartoon Distortion due to curvature
Source Michael Dennis, PE Shepard Wesnitzer
Inc.
55
Horizontal distortion of grid coordinates due to
Earth curvature
Source Michael Dennis, PE Shepard Wesnitzer
Inc.
56
Cartoon Distortion due to change in ellipsoidal
height
Source Michael Dennis, PE Shepard Wesnitzer
Inc.
57
Distortion of grid coordinates due to variation
in ground height
Source Michael Dennis, PE Shepard Wesnitzer
Inc.
58
Cartoon Sloped terrain with respect reference
ellipsoid
Source Michael Dennis, PE Shepard Wesnitzer
Inc.
59
Cartoon Datum transformation to reduce
distortion due to change in height
Source Michael Dennis, PE Shepard Wesnitzer
Inc.
60
Cartoon Sloped projection with reduced linear
distortion
Source Michael Dennis, PE Shepard Wesnitzer
Inc.
61
Datum transformation and projection computation
results
Source Michael Dennis, PE Shepard Wesnitzer
Inc.
62
Verde Valley projection, revisited
Source Michael Dennis, PE Shepard Wesnitzer
Inc.
63
Sloped projection showing 20 ppm distortion area
Source Michael Dennis, PE Shepard Wesnitzer
Inc.
64
Conclusions

Method can substantially reduce linear
distortion in areas of significant relief
Useful for areas and projects where ground
coordinates desired
But limited to areas of more-or-less uniform
topographic slope
Relatively simple to implement
Can be used with any type of projection
Datum transformation can be hidden inside
projection algorithm
Only 2 numbers needed to define transformation
(slopes north east)
Does not restrict transferability of data
Fully reversible Can obtain original reference
geodetic coordinates
Can then re-project coordinates using any other
type of projection

Source Michael Dennis, PE Shepard Wesnitzer
Inc.
65
Geodetic Control
Arizona Geographic Information Council2002 AGIC
Conference
66
GEODETIC CONTROL

NETWORK OF MONUMENTED POINTS
PRECISELY MEASURED IN ACCORDANCE
WITH STANDARD PROCEDURES
MEET ACCURACY SPECIFICATIONS
ADJUSTED TO FIT (or TIE) TOGETHER
DOCUMENTED FOR MULTIPLE USE

67
Stainless steel rod driven to refusal
Poured in place concrete post
68
NATIONAL SPATIAL REFERENCE SYSTEM

The National Spatial Reference System (NSRS) is
that component of the National Spatial Data
Infrastructure (NSDI) - http//www.fgdc.gov/nsdi/
nsdi.html which contains all geodetic control
contained in the National Geodetic Survey (NGS)
Data Base. This includes A, B, First, Second
and Third-Order horizontal and vertical control,
Geoid models such as GEOID 03, precise GPS orbits
and Continuously Operating Reference Stations
(CORS), and the National Shoreline as observed
by NGS as well as data submitted by other
Federal, State, and local agencies, Academic
Institutions and the private sector.

69
NATIONAL SPATIAL REFERENCE SYSTEM

ACCURATE -- cm accuracy on a global scale
MULTIPURPOSE -- Supports Geodesy, Geophysics,
Land Surveying, Navigation, Mapping, Charting and
GIS activities
ACTIVE -- Accessible through Continuously
Operating Reference Stations (CORS) and derived
products (e.g. OPUS)
INTEGRATED -- Related to International services
and standards (e.g. International Earth Rotation
Service, International
GPS Service etc.)

70
NAD 83 NETWORK PROBLEMS

NOT GPSABLE

POOR STATION ACCESSIBILITY
IRREGULAR STATION SPACING
POSITIONAL ACCURACY
71
HIGH ACCURACY REFERENCE NETWORKS

GPSABLE
Clear Horizons for Satellite Signal Acquisition
EASY ACCESSIBILITY
Few Special Vehicle or Property Entrance
Requirements
REGULARLY SPACED
Always within 20-100 Km
HIGH HORIZONTAL ACCURACY
A-Order (5 mm 110,000,000
B-Order (8mm 11,000,000)
HARN, HPGN, FBN
Different acronyms for the same thing

72
HIGH ACCURACY REFERENCE NETWORKS
73
IMPROVING POSITIONAL ACCURACY

TIME NETWORK
LOCAL
NETWORK SPAN ACCURACY ACCURACY
NAD 27 1927-1986
10 Meters First-Order (1 part
in 0.1 million)
NAD 83 1986-1990
1 Meter First-Order(1
part in 0.1 million)
HARN 1987-1997
0.1 Meter B-Order(1
part in 1 million)
A-Order (1 part in 10 million)
CORS 1994 -
0.02 Meter -
Horizontal
0.04
Meter - Ellipsoid Height

74
GEODETIC CONTROL DATA SHEET
1 National Geodetic Survey, Retrieval
Date JULY 9, 2002 DV1145

DV1145 FBN - This is a Federal Base
Network Control Station. DV1145 DESIGNATION -
RAMSEY DV1145 PID - DV1145 DV1145
STATE/COUNTY- AZ/LA PAZ DV1145 USGS QUAD -
PLOMOSA PASS (1990) DV1145 DV1145
CURRENT SURVEY CONTROL DV1145
__________________________________________________
_________________ DV1145 NAD 83(1992)- 33 39
56.95619(N) 114 00 01.91029(W) ADJUSTED
DV1145 NAVD 88 - 475.040 (meters)
1558.53 (feet) ADJUSTED DV1145
__________________________________________________
_________________ DV1145 X -
-2,161,551.447 (meters) COMP
DV1145 Y - -4,854,803.033 (meters)
COMP DV1145 Z -
3,515,902.397 (meters) COMP
DV1145 LAPLACE CORR- 0.61 (seconds)
DEFLEC99 DV1145 ELLIP HEIGHT-
443.70 (meters) GPS
OBS DV1145 GEOID HEIGHT- -31.32
(meters) GEOID99 DV1145
DYNAMIC HT - 474.492 (meters) 1556.73
(feet) COMP DV1145 MODELED GRAV-
979,467.9 (mgal) NAVD 88
DV1145 DV1145 HORZ ORDER - A DV1145 VERT
ORDER - FIRST CLASS II DV1145 ELLP ORDER
- THIRD CLASS I
H h N 475.040 443.70 (-31.32) 475.040 ?
475.02

75
GEODETIC CONTROL DATA SHEET

DV1145SPC AZ W - 295,628.663
190,126.060 MT 0.99993999 -0 08 20.0
DV1145SPC AZ C - 297,539.454 20,094.843
MT 1.00036036 -1 09 20.0 DV1145UTM 11
- 3,729,141.759 778,123.802 MT 1.00055373
1 39 49.7 DV1145UTM 12 - 3,729,144.619
221,777.758 MT 1.00055441 -1 39 51.9
DV1145 DV1145! - Elev Factor x
Scale Factor Combined Factor DV1145!SPC AZ W
- 0.99993035 x 0.99993999
0.99987034 DV1145!SPC AZ C - 0.99993035 x
1.00036036 1.00029068 DV1145!UTM 11
- 0.99993035 x 1.00055373 1.00048404
DV1145!UTM 12 - 0.99993035 x
1.00055441 1.00048472 DV1145
DV1145-------------------------------------------
-------------------------- DV1145 PID
Reference Object Distance
Geod. Az DV1145
dddmmss.s
DV1145 DV1143 RAMSEY RM 1
7.630 METERS 01835 DV1145 DV1147
RAMSEY AZ MK
0680936.4 DV1145 DV1974 LOS ANGELES PHOENIX
AWY BCN 25 APPROX.10.0 KM 1563949.0
DV1145 DV1144 RAMSEY RM 2
11.039 METERS 16926 DV1145--------------
--------------------------------------------------
----- DV1145 DV1145
SUPERSEDED SURVEY CONTROL DV1145 DV1145 ELLIP
H (09/30/92) 443.72 (m)
GP( ) 2 1 DV1145 NAD 83(1986)- 33 39
56.95198(N) 114 00 01.91873(W) AD( ) 2
DV1145 NAD 27 - 33 39 56.84800(N) 113
59 59.12850(W) AD( ) 2 DV1145 NAVD 88
(09/30/92) 475.04 (m) 1558.5 (f)
LEVELING 3 DV1145 NGVD 29 (??/??/92)
474.334 (m) 1556.21 (f) ADJ UNCH 1 2
76
GEODETIC CONTROL DATA SHEET

DV1145 HISTORY - Date Condition
Report By
DV1145 HISTORY - 1949 MONUMENTED
CGS
DV1145 HISTORY - 1962 GOOD
CGS
DV1145 HISTORY - 1962 GOOD
NGS
DV1145 HISTORY - 1965 GOOD
CGS
DV1145 HISTORY - 1971 GOOD
USE
DV1145 HISTORY - 1981 GOOD
NGS
DV1145 HISTORY - 1981 GOOD
NGS
DV1145 HISTORY - 1981 GOOD
NGS
DV1145 HISTORY - 1985 GOOD
AZDT
DV1145 HISTORY - 19920203 GOOD
NGS
DV1145 HISTORY - 19960306 GOOD
CHANCE
DV1145 HISTORY - 19981111 GOOD
NGS
DV1145 HISTORY - 19981117 GOOD
AZ-013
DV1145
DV1145 STATION
DESCRIPTION
DV1145
DV1145'DESCRIBED BY COAST AND GEODETIC SURVEY
1949 (DHK)
DV1145'STATION LOCATED ABOUT 17 MILES AIR LINE
WEST OF HOPE, 13

77
GEODETIC CONTROL DATA SOURCES

NGS web site www.ngs.noaa.gov/datasheet.html
on-line search for control and generates data
sheets (text search)
SDTS (Spatial Data Transfer Standard) format for
import of data into GIS software (very large
files)
Shapefiles coming soon
State Cartographers website -
http//sco.az.gov/ngs.htm
DSWIN software data files (by county)
used to search for control and generate data
sheets (text search)
used to generate text files for import into GIS
software
used to generate text files for import into GPS
receivers
Arizona GeoServer - sco.az.gov/website/geoserver
/
on-line search for control and generate data
sheets with a GUI

78
NEW STANDARDS FOR GEODETIC CONTROL

Two accuracy standards
(http//fgdc.er.usgs.gov/standards/status/swgstat.
html)
local accuracy ------------- adjacent
points
network accuracy ---------- relative to CORS
Numeric quantities, units in cm (or mm)
Both are relative accuracy measures
Do not use distance dependent expression
Horizontal accuracies are radius of 2-D 95 error
circle
Ellipsoidal/Orthometric heights are 1-D (linear)
95 error

79
Datum Transformations
Arizona Geographic Information Council2002 AGIC
Conference
80
DATUM TRANSFORMATIONS

1. WHAT DATUM ARE THE EXISTING COORDINATES ON?
2. WHAT DATUM DO I WANT THE NEW COORDINATES ON?
3. HOW LARGE A GEOGRAPHICAL AREA DO I WANT TO
CONVERT AT ONE TIME?
4. HOW MANY POINTS ARE COMMON TO BOTH DATUMS?
5. WHAT IS THE DISTRIBUTION OF THE COMMON
POINTS?
6. HOW ACCURATE ARE THE EXISTING COORDINATES?
0.1 Foot
1.0 Foot
10. Feet
7. HOW ACCURATE DO I WANT THE NEW COORDINATES?

81
DATUM TRANSFORMATION IDEAL METHOD

SATISFIES ALL USERS REQUIREMENTS
CAPABLE OF TRANSFORMING LARGE HOLDINGS OF
COORDINATE DATA
NEAR-REAL TIME APPLICATIONS
SIMPLE - METHOD SHOULD NOT REQUIRE AN EXPERT OR
EXPERT DECISIONS TO BE MADE
ACCURATE

82
DATUM TRANSFORMATIONS

MOLODENSKY
Converts latitude, longitude and ellipsoidal
height to X,Y,Z Earth-Centered Coordinates.
Applies a 3-dimensional change in the origin (dX,
dY,dZ)
Applies a change in the size and shape of the
reference ellipsoid
Converts new X,Y,Z Earth-Centered Coordinates
back to latitude, longitude and ellipsoidal
height

83
DATUM TRANSFORMATIONS

MOLODENSKY
For continental regions accuracy can be /- 8
to 10 meters
Does not model network distortions very well.
Assumes heights in both systems are ellipsoidal
(NAD 27 did not have ellipsoidal heights).

84
MOLODENSKY TRANSFORMATION
(http//www.nima.mil/GandG/pubs.html)
85
NADCON

DESIGNED TO SATISFY THE MAJORITY OF THE IDEAL
METHOD DESIGN AND IS DEFINED AS THE NATIONAL
STANDARD.
DESIGN CRITERIA
Relies only on NGS archived data existing in both
NAD 27 and NAD 83
Not tied to NGS Data Base
Provides consistent results, both forward and
inverse
Fast
Small - Fits on a PC
Accurate
15 cm (1 sigma) in Conterminous U.S. NAD 27 -
NAD 83 (1986)
5 cm (1 sigma) per State/Region NAD 83 (1986) -
HARN

Federal Register Notice Vol. 55, No. 155, August
10, 1990, pg. 32681 Notice to Adopt Standard
Method for Mathematical Horizontal Datum
Transformation
86
How does NADCON work?
N 0.12344 8 -1.87842
N 0.12249 8 -1.88963
Set of gridded NAD-27 network distortion factors
Positional error due To distortion
N 0.12423 8 -1.81246
N 0.12568 8 -1.83364
N 0.12449 8 -1.88905
NSRS survey station
N 0.12640 8 -1.85407
N 0.12499 8 -1.86543
87
COORDINATE COMPARISONNAD 27 to NAD 83(1992)

ADJUSTED vs. TRANSFORMED
Station RAMSEY
LATITUDE
LONGITUDE
33-39-56.95619 114-00-01.91029
PUBLISHED (NAD83 (92))
33-39-57.01410
114-00-01.92238 - MOLODENSKY
0
.05791 0.01209
1.784 m 0.312 m
THIS CORRESPONDS TO A POSITIONAL
DIFFERENCE OF 1.811 m (5.94 ft)

88
COORDINATE COMPARISON NAD 27 to NAD
83(1992)

NADCON
http//www.ngs.noaa.gov/TOOLS/NADCON
ADJUSTED vs. TRANSFORMED
Station RAMSEY
LATITUDE LONGITUDE
33-39-56.95619 114-00-01.91029 - PUBLISHED
33-39-56.95626 114-00-01.90498 - NADCON
.0007 .00531
0.002 m 0.137 m
THIS CORRESPONDS TO A POSITIONAL
DIFFERENCE OF 0.137 m (0.45 ft)

89
COORDINATE COMPARISONNAD 27 to NAD 83(1996)

ADJUSTED vs. TRANSFORMED
Station RED STONE
LATITUDE
LONGITUDE
44-28-13.93221
073-11-46.77900 - PUBLISHED
44-28-13.75032
073-11-46.60413 - MOLODENSKY
.18189 .17487
5.614 m 3.865 m
THIS CORRESPONDS TO A POSITIONAL
DIFFERENCE OF 6.816 m (22.36 ft)

90
COORDINATE COMPARISON NAD 27 to NAD
83(1996)

NADCON
ADJUSTED vs. TRANSFORMED
Station RED STONE
LATITUDE LONGITUDE
44-28-13.93221
073-11-46.77900 - PUBLISHED
44-28-13.93057
073-11-46.77912 - NADCON
.00164 .00012
0.051 m 0.003 m
THIS CORRESPONDS TO A POSITIONAL
DIFFERENCE OF 0.051m (0.17 ft)

91
GPS Positions What datum are they on?

Autonomous GPS
- WGS84 (almost ITRF)
US Coast Guard DGPS (a.k.a. beacon)
- NAD83
FAA WAAS DGPS
- ITRF (200?)
Differentially corrected GPS
- What Datum is the reference station on?

92
Public Land Survey System (PLSS)
Arizona Geographic Information Council2002 AGIC
Conference
93
Public Land Survey System

A rectangular coordinate system based on a
somewhat arbitrary point (Initial Point)
Did not have geographic positions as part of the
system
A system to support land ownership or conveyance
not mapping
Depiction on USGS quads may or may not be based
on field verification
ALRIS source is digitized USGS Quads

94
Public Land Survey SystemGeographic Coordinate
Data Base (GCDB)

Maintained by BLM on a state by state basis
Current lack of national policy
Might be on NAD 27 or NAD 83
NOT a legal depiction of the corner location
Average of all available positions
Available at www.blm.gov/gcdb/

95
PLSS corner accuracy
Position comparison courtesy of Tim Smothers,
City of Peoria
96
AZ/CA Boundary Project Yuma Area
97
GPS Data Sources and Services from NGS
Arizona Geographic Information Council2002 AGIC
Conference
98
Geodetic Tool Kit

www.ngs.noaa.gov/TOOLS/
99
CONTINUOUSLY OPERATING REFERENCE STATIONS (CORS)

Variety of Geodetic Quality Dual-Frequency
Antennas and Receivers
Allen-Osborne
(SNR 8000 SNR 12 ACT)
Ashtech
(UZ-12, Z-XII3)
Leica
(SR9500 CRS1000, LEIAT5, RS500)
Trimble
(4000SS, 4700, 5700)

CHL1 - CAPE HENLOPEN, DE
100
(No Transcript)
101
CONTINUOUSLY OPERATING REFERENCE STATIONS (CORS)

Some stations broadcast real-time correctors
1- 5 - 15 30 sec. post-process carrier phase
observations
Free access via Internet (RINEX-2 Format)
More than 285 Station National Network

102
CONTINUOUSLY OPERATING REFERENCE STATIONS (CORS)

NGS PROVIDES
Reference Site Survey Monumentation
Horizontal and Vertical NSRS Connections
NAD 83, ITRF94, ITRF96, ITRF97, ITRF00
Coordinates
Network Data Collection - Hourly Daily
Daily 3D Network Integrity Adjustment
Public Data Distribution - Internet
(http//www.ngs.noaa.gov/CORS/cors-data.html)
7 Year On-Line Data Holding

103
(No Transcript)
104
(No Transcript)
105
(No Transcript)
106
CORS DATA SHEET

ITRF 00 NAVAL STATION NEW
(NPRI), RHODE ISLAND Retrieved from NGS
DataBase on 04/06/02 at 181130.
__________________________________________________
__________________________

Antenna Reference Point(ARP)
NAVAL STATION NEW CORS ARP
--------------------------------------------------
------
PID AI3285

ITRF00 POSITION (EPOCH 1997.0)
Computed
in Aug. 2001 using every third day of data
through 2000. X 1531392.471
m latitude 41 30 35.44671 N
Y -4531474.016 m longitude
071 19 39.12747 W Z
4204982.604 m ellipsoid height -13.015 m

ITRF00 VELOCITY
Predicted with
HTDP_2.5 in Aug. 2001.
VX -0.0165 m/yr
northward 0.0044 m/yr
VY -0.0025 m/yr eastward
-0.0164 m/yr VZ
0.0033 m/yr upward 0.0000 m/yr

107
CORS DATA SHEET

NAD 83
NAD_83 POSITION
(EPOCH 2002.0)
Transformed from ITRF00 (epoch
1997.0) position in Mar. 2002.
X 1531393.023 m latitude 41 30
35.41588 N Y
-4531475.481 m longitude 071 19 39.12515
W Z 4204982.718 m
ellipsoid height -11.768 m

NAD_83 VELOCITY

Transformed from ITRF00 velocity in
Mar. 2002. VX
0.0005 m/yr northward -0.0014 m/yr
VY -0.0006 m/yr
eastward 0.0003 m/yr
VZ -0.0012 m/yr upward
-0.0002 m/yr
_______________________________________________
_____________________________

108
OPUS WHAT IS IT?

On-line Positioning User Service
Provides GPS users faster easier access to the
National Spatial Reference System (NSRS)

109
OPUS What Do I need?

Dual Frequency GPS (carrier phase) data
Resource-grade GPS unit probably NOT suitable
Stationary antenna (no kinematic data)
Single station no networks
Data rates of 1, 2, 3, 5, 6, 10, 15 or 30
seconds
At least 2 hours of GPS data
RINEX generator (software)
Converts GPS data from manufacturers format to
industry standard format
TEQC free from UNAVCO
http//www.unavco.ucar.edu/data_support/softwa
re/translation/translation.html

110
OPUS How do I use it?

Go to OPUS web page www.ngs.noaa.gov/OPUS
Enter your email address
Use browse feature to select RINEX file on your
computer
Select antenna type from menu
Enter antenna height in meters
Option to select State Plane Zone
Click UPLOAD
Check your email in a few minutes

111
OPUS What do I get?
REF FRAME NAD83(CORS96)(EPOCH2002.0000)
ITRF97 (EPOCH2000.2843) X
-1933229.787(m) 0.006(m)
-1933230.343(m) 0.110(m)
Y -5043636.636(m) 0.022(m)
-5043635.169(m)
0.192(m) Z 3381904.220(m)
0.038(m)
3381904.084(m) 0.151(m) LAT 32
13 28.02620 0.023(m)
32 13 28.04274 0.011(m) E
LON 249 1 41.28058 0.012(m)
249 1 41.24070
0.040(m) W LON 110 58 18.71942
0.012(m) 110 58
18.75930 0.040(m) EL HGT
734.110(m) 0.036(m)
733.047(m) 0.265(m) ORTHO
HGT 763.270(m) 0.044(m) Geoid99
NAVD88 UTM Zone 12
SPC Zone
202(AZ) NORTHING 3565315.261(m)
NORTHING 136145.249(m)
EASTING 502650.865(m)
EASTING 302411.814(m)
112
GPS Update Whats upfor the Future?
Arizona Geographic Information Council2002 AGIC
Conference
113
Autonomous Positioning Before May 1, 2000
25-100 m
HORIZONTAL 100 meters
VERTICAL 156 meters
1996 Federal Radionavigation Plan Section A2-1,
Part B http//www.navcen.uscg.mil/policy/frp1996