Ross Mackay

1
Ross Mackay Kentucky Geodetic Advisor
Danielle Buchanan KY Transportation Cabinet
Timothy Hare Morehead State University
Kentucky CORS, Height Modernization and Real Time
Network
2009 Conference Kentucky Association of
Professional Surveyors Lexington,
Kentucky February 19, 2009
02/18/2009
2

• Introduction to KY Height Mod
• purpose and outcomes
• development of KY CORS
• orthometric heights at CORS
• Using OPUS-S and OPUS-RS
• using the applications
• comparison of results
• OPUS-DB, an NGS archive

3
National Spatial Reference System
Geodetic Datum a set of constants specifying
the coordinate system used for geodetic
control and the set of all points and lines
whose coordinates, lengths, and directions have
been determined by measurement or calculation.
Geodetic Datum a set of constants specifying
the coordinate system used for geodetic
control and the set of all points and lines
whose coordinates, lengths, and directions have
been determined by measurement or calculation.
realization of the datum
4
Height Modernization in Kentucky

Topographic Surface
H
h
Ellipsoid
Geoid
h Ellipsoidal Height
5
Height Modernization in Kentucky
Continuously Operating Reference Stations
6
Height Modernization in Kentucky
2002 Geographic Information Council Subcommittee
develops KY Height Mod implementation plan
2003 Independent meetings and coordination
with Morehead State University 2004 Kentucky
Height Mod Forum, Congressman Rogers announces
FY'05 appropriation 2005 FY'05 appropriation
funds Kentucky CORS network 2006 Installation
of KY CORS continues 2007 KY CORS network
completed, leveling project planning for transfer
of heights to CORS ARP 2008 Leveling completed
for most of Eastern KY CORS, project plans
approved for remaining CORS 2009 Complete
leveling to CORS
7
Height Modernization in Kentucky
8
Height Modernization in Kentucky

• Morehead, KYMH
• Cumberland, KYCB
• Somerset, KYSC
• Campbellsville, KYCB
• Taylor Lake, Lou5
• Madisonville , KYTB
• Bowling Green, KYTC
• Elizabethtown, KYTD
• Louisville, KYTE
• Covington, KYTF
• Lexington, KYTG
• Somerset, KYTH
• Flemingsburg, KYTI
• Manchester, KYTK
• Pikeville, KYTL
• Greenbo Lake SRP, KYGB
• Dale Hollow SRP, KYDH
• Rough River SRP, KYRR

• Paducah, KYTA
• Jackson, KYTJ

9
Height Modernization in Kentucky
Some things never change
10
Height Modernization in Kentucky
But they do get digital.
11
Height Modernization in Kentucky
Transfer elevations from existing benchmarks to
CORS Antenna Reference Point
12
Height Modernization in Kentucky

• Find benchmarks
• Validate heights
• Geodetic leveling
• Transfer heights
• to ARP

13
Height Modernization in Kentucky
Geoid03
14
Height Modernization in Kentucky
Geoid09, beta
15
Height Modernization in Kentucky
16
Height Modernization in Kentucky
17
Height Modernization in Kentucky
18
Height Modernization in Kentucky
equipotential gravity field
The geoid can be as low as 106 meters (350 feet)
below the ellipsoid or as high as 85 meters (280
feet) above.
NASAs GRACE Gravity Recovery and Climate
Experiment
19
GRAV-DGravity for the Redefinition of the
American Vertical Datum
Height Modernization in Kentucky

• Official NGS policy (as of Nov 14, 2007)
• Airborne gravity survey (10 years)
• Gravity monitoring into the future
• Coastal areas surveyed first
• All USA states and territories
• www.ngs.noaa.gov/GRAV-D
• 2017 Targets
• Orthometric heights good to 2 cm anywhere,
  anytime from GNSS technology
• Height changes easily monitored using new
  vertical datum

20
Absolute gravimeterExample Micro-g Solutions
FG5
Height Modernization in Kentucky

• Ballistic (free-fall) of retro- reflector in
  vacuum chamber, tracked by laser beam
• Instrument accuracy and precision 1.1 mGals
• Used for temporal change of g

21
(No Transcript)
22
OPUS
National CORS Network

• 1387 National CORS
• 166 Cooperative CORS
• February 17, 2009

23
CORS Network Evolution
OPUS
1994
1997
2000
2003
2006
2008
24
OPUS
Online Positioning User Service
25
How does OPUS-S compute your position?
OPUS
3 single baselines computed
solution 2
CORS solution 1
solution 3
3 positions averaged simple mean (equal
weights)
26
OPUS Guidelines
OPUS
formerly known as OPUS

• Your data must be dual frequency (L1 and L2),
• contain at least 2 hours of observations
• and have a collection rate of 1,2,3,5,10,15 or
  30 seconds

• Your data must be dual frequency (L1 and L2),
• contain between 15 minutes and 4 hours of
  observations
• and have a collection rate of 1,2,3,5,10,15 or
  30 seconds.

27
OPUS
28
OPUS (Online Positioning User Service)
OPUS
combined
29
OPUS
2008 Totals OPUS-S 2731 OPUS-RS 1146
30
OPUS
2008 Total NGS web downloads 22392
31
OPUS
32
OPUS
Quick Link to OPUS from NGS Home
Page www.ngs.noaa.gov
33
Using the OPUS Web Page
OPUS
34
OPUS Options
OPUS
specify State Plane Coordinate System
specify CORS to use, or not use
35
OPUS
more OPUS Options
Extended output
XML output
OPUS project
user profile
36
OPUS
OPUS Upload Confirmation
37
OPUS

• Antenna Height
• true vertical distance
• measured in meters

ARP
MARK
38
Why do I need the antenna type?
OPUS
The antenna phase centers are located somewhere
around here.
The antenna offsets are the distance between the
phase centers and the ARP
ARP
You do not need to know these offsets. They are
passed to the processing software through the
antenna type
The Antenna Reference Point (ARP) is almost
always located in the center of the bottom
surface of the antenna.
Incorrect or missing antenna type ? big vertical
errors
39
OPUS
. . . . . . . . . . . .
Antenna Phase Center Variation
SV 20
SV 20
SV 14
SV 14
Different Phase Patterns
SV elevation and varying phase patterns affect
signal interpretation differently
Antenna Type B
Antenna Type A
40
Multipath
OPUS

• multiple signal paths between satellite and
  receiver
• caused by reflected signals within receiver
  environment
• chain link fences
• vehicles
• road signs
• to reduce multipath, use ground plane and avoid
  nearby reflective surfaces

41
OPUS
FILE corv0590.05o 000416827 1008 NOTE
Antenna offsets supplied by the user were zero.
Coordinates 1008 returned will be for the
antenna reference point (ARP). 1008
NGS OPUS SOLUTION REPORT

USER jeff.olsen_at_noaa.gov
DATE January 13, 2006 RINEX FILE corv059f.05o
TIME 190814 UTC
SOFTWARE page5 0601.10 master3.pl
START 2005/02/28 050000 EPHEMERIS
igs13121.eph precise STOP
2005/02/28 065930 NAV FILE brdc0590.05n
OBS USED 4228 / 4314
98 ANT NAME ASH700936B_M NONE
FIXED AMB 25 / 29 86 ARP HEIGHT
0.0 OVERALL RMS
0.013(m) REF FRAME NAD_83(CORS96)(EPOCH2002.0
000) ITRF00 (EPOCH2005.1596)
X -2498423.165(m) 0.018(m)
-2498423.872(m) 0.018(m) Y
-3802822.048(m) 0.021(m)
-3802820.836(m) 0.021(m) Z
4454737.695(m) 0.024(m)
4454737.792(m) 0.024(m) LAT 44 35
7.91054 0.002(m) 44 35 7.92698
0.002(m) E LON 236 41 43.48129
0.014(m) 236 41 43.42434 0.014(m)
W LON 123 18 16.51871 0.014(m) 123
18 16.57566 0.014(m) EL HGT
107.485(m) 0.034(m) 107.108(m)
0.034(m) ORTHO HGT 130.010(m)
0.043(m) Geoid03 NAVD88
UTM COORDINATES STATE PLANE COORDINATES
UTM (Zone 10) SPC
(3601 OR N) Northing (Y) meters 4936954.907
105971.557 Easting (X) meters
475821.322 2277335.385 Convergence
degrees -0.21381402
-1.98897497 Point Scale 0.99960719
0.99994603 Combined Factor
0.99959034 0.99992918 US NATIONAL GRID
DESIGNATOR 10TDQ7582136955(NAD 83)
BASE STATIONS USED PID
DESIGNATION LATITUDE
LONGITUDE DISTANCE(m) AH2489 NEWP NEWPORT CORS
ARP N443506.072 W1240342.736
60138.7 AJ6959 CHZZ CAPE MEARS CORS ARP
N452911.437 W1235841.187 113322.4 DH4503 P376
EOLARESVR_OR2004 CORS ARP N445628.313
W1230608.100 42648.2 NEAREST
NGS PUBLISHED CONTROL POINT AH2486 CORVALLIS
CORS ARP N443507.910 W1231816.519
0.0
OPUS OutputStandard
42
Reading OPUS Output
OPUS
USER jeff.olsen_at_noaa.gov
DATE January 13, 2006 RINEX FILE corv059f.05o
TIME 190814 UTC
SOFTWARE page5 0601.10 master3.pl
START 2005/02/28 050000 EPHEMERIS
igs13121.eph precise STOP
2005/02/28 065930 NAV FILE brdc0590.05n
OBS USED 4228 / 4314
98 ANT NAME ASH700936B_M NONE
FIXED AMB 25 / 29 86 ARP HEIGHT
0.0 OVERALL RMS
0.013(m)

• Your email address observation file. Solution
  run date time

• The version of PAGES software used for
  processing

• The ephemeris used (OPUS will use the best
  available)
• igs final post-fit orbit--better than 1 cm
  (10-14 days wait)
• igr rapid post-fit orbit--better than 2 cm (17
  hours wait)
• igu ultra-rapid predicted orbit--better than
  20 cm (available
• immediately)
• Navigation file used

• The antenna type you selected and height of
  antenna reference point height you entered.
  Confirm that these are correct.

43
Reading OPUS Output (continued)
OPUS
USER jeff.olsen_at_noaa.gov
DATE January 13, 2006 RINEX FILE corv059f.05o
TIME 190814 UTC
SOFTWARE page5 0601.10 master3.pl
START 2005/02/28 050000 EPHEMERIS
igs13121.eph precise STOP
2005/02/28 065930 NAV FILE brdc0590.05n
OBS USED 4228 / 4314
98 ANT NAME ASH700936B_M NONE
FIXED AMB 25 / 29 86 ARP HEIGHT
0.0 OVERALL RMS
0.013(m)

• Start and end date time of your file

• Ratio and of observations used in solution

• Ratio and of fixed/total ambiguities

• Overall RMS of the solution

44
Reading OPUS Output Solution/Coordinates
OPUS

• REF FRAME NAD_83(CORS96)(EPOCH2002.0000)
  ITRF00 (EPOCH2005.1596)
• X -2498423.165(m) 0.018(m)
  -2498423.872(m) 0.018(m)
• Y -3802822.048(m) 0.021(m)
  -3802820.836(m) 0.021(m)
• Z 4454737.695(m) 0.024(m)
  4454737.792(m) 0.024(m)
• LAT 44 35 7.91054 0.002(m)
  44 35 7.92698 0.002(m)
• E LON 236 41 43.48129 0.014(m)
  236 41 43.42434 0.014(m)
• W LON 123 18 16.51871 0.014(m)
  123 18 16.57566 0.014(m)
• EL HGT 107.485(m) 0.034(m)
  107.108(m) 0.034(m)
• ORTHO HGT 130.010(m) 0.043(m)

Geoid03 NAVD88

• Reference frames. Epochs

• Position, xyz

• Peak-peak errors, xyz (range, max-min)

• Position, lat / long / eh / oh

• Peak-peak for lat/long etc

• Peak-peak errors may vary between NAD83 ITRF

• Orthometric ht. is based on current geoid model

45
OPUS
GPS-derived ITRF Horizontal Velocities
46
OPUS Output (continued)Grid Coordinates
OPUS

• UTM COORDINATES STATE PLANE COORDINATES
• UTM (Zone 10)
  SPC (3601 OR N)
• Northing (Y) meters 4936954.907
  105971.557
• Easting (X) meters 475821.322
  2277335.385
• Convergence degrees -0.21381402
  -1.98897497
• Point Scale 0.99960719
  0.99994603
• Combined Factor 0.99959034
  0.99992918
• US NATIONAL GRID DESIGNATOR 10TDQ7582136955(NAD
  83)

• Universal Transverse Mercator (UTM) coordinates

• US National Grid

• State Plane coordinates (if requested)

47
OPUS
Reading OPUS Output (continued)

• BASE STATIONS USED
• PID DESIGNATION
  LATITUDE LONGITUDE DISTANCE(m)
• AH2489 NEWP NEWPORT CORS ARP
  N443506.072 W1240342.736 60138.7
• AJ6959 CHZZ CAPE MEARS CORS ARP
  N452911.437 W1235841.187 113322.4
• DH4503 P376 EOLARESVR_OR2004 CORS ARP
  N445628.313 W1230608.100 42648.2
• NEAREST NGS PUBLISHED CONTROL
  POINT
• AH2486 CORVALLIS CORS ARP
  N443507.910 W1231816.519 0.0
• This position and the above vector components
  were computed without any
• knowledge by the National Geodetic Survey
  regarding the equipment or
• field operating procedures used.

• Base Stations--NAD83 position--distance away

• The closest published station in the NGS data
  base
• In case you didnt know it was there

• Disclaimer

48
How Does OPUS Compute Errors?
OPUS
peak-to-peak distances
N
1 s standard deviation
W
E
peak-to-peak error 2 s
S
49
Guidelines for Good Solution
OPUS

• Make sure antenna type and height are correct

• Review statistics
• at least 90 of observations should be used
• OBS USED 4228 / 4314 98
• at least 50 of the ambiguities should be fixed
• FIXED AMB 25 / 29 86
• overall RMS should seldom exceed 0.030 m
• OVERALL RMS 0.013(m)

• In case of bad statistics, try choosing
  different CORS and re-submit.

50
How Can I Improve My Results?
OPUS

• Consider observing a longer session

- Data sets of at least four hours have been
shown to produce more reliable results

• Avoid conditions that perturb the GPS
  signalunsettled weather, solar flares, multipath
  (nearby reflective surfaces)

51
Horizontal Error
OPUS

• gt 200 CORS stations
• 2 hours of data
• 0.8 cm N-S RMS
• 1.4 cm E-W RMS

52
Vertical Error
OPUS

• gt 200 CORS stations
• 2 hours of data
• 1.9 cm ellipsoid
• height RMS

53
How do I get help?
OPUS

• Study the Guidelines under Using OPUS

• Review the answers
• under FAQs

• Submit specific questions, comments or
  suggestions using Contact OPUS link

54
OPUS-RS
OPUS-RS (Rapid Static)

• 15-minute sessions
• ties to 3 9 CORS (lt 250km)
• uses RSGPS vs. PAGES software
• similar to Real-Time Network computations
• Rapid Static GPS solution modes
• network solves ambiguities, tropo, iono
• rover tropo and ion interpolated to rover

55
OPUS-RS Search Algorithm
OPUS-RS

• form Delaunay Triangulation of candidate CORS
• select 3 CORS in triangle
• enclosing rover, or
• closest to the rover
• expand selection process to include up to 9 CORS

56
OPUS-RS Output
OPUS-RS
NGS OPUS-RS SOLUTION REPORT     USER
william.stone_at_noaa.gov                 DATE
October 29, 2007 RINEX FILE 1207287x.07o  
                      TIME 143904
UTC  SOFTWARE rsgps  1.09 RS11.prl 1.12    
START 2007/10/14 232715 EPHEMERIS
igr14490.eph rapid                     STOP
2007/10/15 000015 NAV
FILE brdc2870.07n                        OBS
USED   1962 /  2082    94
ANT NAME ASH701975.01A                
QUALITY IND.   34.21/ 37.91 ARP HEIGHT 0.0    
                      NORMALIZED RMS 0.307
 REF FRAME NAD_83(CORS96)(EPOCH2002.0000)  
 ITRF00 (EPOCH2007.78627)    
LAT 36  2 52.79767      0.008(m)       36  2
52.81498     0.008(m)      E LON   252  2
18.45532    0.013(m)       252  2 18.41156  
  0.013(m)      W LON   107 57 41.54468
 0.013(m)       107 57 41.58844     0.013(m)   
  EL HGT         1974.304(m)  
0.005(m)       1973.396(m)   0.005(m)  ORTHO
HGT         1995.280(m)   0.026(m)
Geoid03 NAVD88

• Fixed Ambiguities replaced by Quality
  Indicator
• average of W-ratio (separation between candidate
  sets of ambiguities) of last 3 epochs
• reported as network mode / rover mode
• look for values gt 3 for confidence in solution

57
OPUS-RS Output
OPUS-RS
NGS OPUS-RS SOLUTION REPORT     USER
william.stone_at_noaa.gov                 DATE
October 29, 2007 RINEX FILE 1207287x.07o  
                      TIME 143904
UTC  SOFTWARE rsgps  1.09 RS11.prl 1.12    
START 2007/10/14 232715 EPHEMERIS
igr14490.eph rapid                     STOP
2007/10/15 000015 NAV
FILE brdc2870.07n                        OBS
USED   1962 /  2082    94
ANT NAME ASH701975.01A                
QUALITY IND.   34.21/ 37.91 ARP HEIGHT 0.0    
                      NORMALIZED RMS 0.307
 REF FRAME NAD_83(CORS96)(EPOCH2002.0000)  
 ITRF00 (EPOCH2007.78627)    
LAT 36  2 52.79767      0.008(m)       36  2
52.81498     0.008(m)      E LON   252  2
18.45532    0.013(m)       252  2 18.41156  
  0.013(m)      W LON   107 57 41.54468
 0.013(m)       107 57 41.58844     0.013(m)   
  EL HGT         1974.304(m)  
0.005(m)       1973.396(m)   0.005(m)  ORTHO
HGT         1995.280(m)   0.026(m)
Geoid03 NAVD88

• Overall RMS replaced by Normalized RMS
• unitless quantity, expected 1
• aka standard deviation of unit weight
• if gt 1, noisy data somewhere
• typically lt1, meaning noise less than expected

58
OPUS-RS Output
OPUS-RS
NGS OPUS-RS SOLUTION REPORT     USER
william.stone_at_noaa.gov                 DATE
October 29, 2007 RINEX FILE 1207287x.07o  
                      TIME 143904
UTC  SOFTWARE rsgps  1.09 RS11.prl 1.12    
START 2007/10/14 232715 EPHEMERIS
igr14490.eph rapid                     STOP
2007/10/15 000015 NAV
FILE brdc2870.07n                        OBS
USED   1962 /  2082    94
ANT NAME ASH701975.01A                
QUALITY IND.   34.21/ 37.91 ARP HEIGHT 0.0    
                      NORMALIZED RMS 0.307
 REF FRAME NAD_83(CORS96)(EPOCH2002.0000)  
 ITRF00 (EPOCH2007.78627)    
LAT 36  2 52.79767      0.008(m)       36  2
52.81498     0.008(m)      E LON   252  2
18.45532    0.013(m)       252  2 18.41156  
  0.013(m)      W LON   107 57 41.54468
 0.013(m)       107 57 41.58844     0.013(m)   
  EL HGT         1974.304(m)  
0.005(m)       1973.396(m)   0.005(m)  ORTHO
HGT         1995.280(m)   0.026(m)
Geoid03 NAVD88

• Peak-to-Peak replaced by Est. Standard Deviations
• approximately 95 confidence
• derived from scatter of single baseline
  solutions
• formal standard deviations (optimistic)
  available
• in Extended Output

59
(No Transcript)
60
OPUS test
Comparing OPUS-S and OPUS-RS
KentuckyCORS Network
61
OPUS test
OPUS-S
62
OPUS test
OPUS-S
63
OPUS test
OPUS-SRepeat Sessions
Vertical Scale 1.5 CMgt ½ inch
64
OPUS test
OPUS-RS
65
OPUS test
OPUS-RSRepeat Sessions
Vertical Scale 5 CM, 2 inches
66
OPUS test
GPS Planning Software
67
Many Flavors of OPUS
OPUS

• OPUS-S (Static, formerly OPUS)
• receiver, hours of data, no archive
• OPUS-RS (Rapid Static)
• receiver, minutes of data, no archive
• OPUS-DB (Database)
• archive of OPUS-S results
• (operational prototype)
• OPUS Projects
• multiple receivers, archive results
• OPUS GIS
• receiver, minutes of data, no archive

68
OPUS, beta
69
OPUS, beta
70
NGS County Scorecard
NOAA has a new performance metric that assesses
how well we are doing at enabling local
capacity for accurate positioning.
71
CORS Applications
RTK and RTN
72
CORS Applications

• Single Baseline RTK
• NTRIP protocol
• Streaming data
• Usually 5 second
• Wireless internet connection
• Cell phone with data package

• URL is http//159.19.10.282101
• Unrestricted access
• No user name/password
• Contact
• Danielle,Buchanan_at_ky.gov
• [phone] x3420

• Real Time Network
• Being researched this year
• Probable fee

73
National Spatial Reference System

• Pending Issues
• EDM Calibration Baselines
• KY Single Zone in KRS 1.020
• KY/TN boundary stones in OPUS-DB

74
Ross Mackay Kentucky Geodetic Advisor
ross.mackay_at_ky.gov on the web at ngs.ky.gov (502
) 564-1474