© 2009 herbert, rowland & grubic, inc. opus and vrs for qa surveys of the pamap program eric m....

© 2009 Herbert, Rowland & Grubic, Inc.

OPUS and VRS for QA Surveys of the

PAMAP Program

Eric M. Orndorff, MS, PLSZach Lupold, BS

Great Lakes RegionHeight ModernizationConsortium Meeting

April 13, 2011


Overview

• Pre-OPUS/VRS (conventional, radio-based RTK)

• Point-to-point wireless RTK

• RTN (VRS network and point solutions)


Overview

• Point-to-point wireless RTK

• PAMAP QA Surveys Evolution– Point-to-point wireless RTK and OPUS– RTN (VRS network and point solutions)

Point-to-point wireless RTKBackground



Point-to-point wireless RTK

• 2005 research (academic)– Investigate vertical accuracy as a function baseline lengths

and occupation times– Double run, triple wire line of levels run through marks for

determining their orthometric heights as related to NAVD88

• 2007 research (random/reality)– Investigate NAVSTAR/GLONASS versus NAVSTAR only

solutions – Varying baseline distances when comparing 1st and 2nd

observations (TIDAL BASIC and GIS96 base stations)– Elevations vary from 6’ to 450’; baselines vary up to 18 miles



1 Sec. 3 Sec. 10 Sec. 60 Sec.120 Sec. 180 Sec.

240 Sec.

300 Sec.

6k 0.007 0.008 0.003 0.002 0.000 0.001 0.001 0.002

8k 0.021 0.025 0.025 0.035 0.032 0.033 0.037 0.038

10k 0.019 0.018 0.018 0.010 0.004 0.001 0.000 0.001

12k 0.011 0.004 0.006 0.014 0.016 0.017 0.015 0.014

14k 0.014 0.007 0.015 0.019 0.020 0.023 0.024 0.025

16k 0.009 0.004 0.005 0.005 0.003 0.009 0.011 0.010

18k 0.040 0.039 0.035 0.028 0.022 0.026 0.030 0.030

20k 0.024 0.018 0.014 0.015 0.017 0.015 0.011 0.009

2005 Research Results



2007 Project Area

• Wireless (point-to-point) RTK:– Trimble R8 GNSS base and rover– Airlink CDMA modem– Verizon Wireless

• 52 photo-identifiable points• 110 Sq. Mi. Area• Support orthophotography for planning of the

“Green Line” corridor.



2007 Project Area



2007 Research Results 1st. Observation Minus 2nd. Observation Squared Mean of Observations

U.S. Survey Ft. Maryland SPC NAD 83 (1986) U.S. Survey Ft. NAVD 88

NORTHING EASTING ELEVATION POINT # NORTHING EASTING ELEVATION

0.009604 0.002025 0.000961 1 586857.555 1418337.450 16.204

0.000625 0.000225 0.005184 2 585513.786 1425187.561 6.410

0.000169 0.001156 0.013924 3 595492.344 1416594.279 139.319

0.000081 0.000144 0.000676 4 594330.431 1424438.626 39.497

0.003364 0.005625 0.029929 5 607041.138 1417505.118 229.523

0.005041 0.000004 0.000016 6 605633.440 1424963.086 215.580

0.037249 0.006400 0.005625 7 620944.045 1418027.337 418.798

0.000784 0.008464 0.000256 8 620561.828 1424527.832 356.950

0.000441 0.003249 0.000961 9 636488.836 1417726.978 346.931

0.003136 0.000484 0.015376 10 635055.078 1424486.366 373.185

0.000256 0.001225 0.003025 11 582592.651 1430195.245 25.616

0.000049 0.001681 0.001024 12 587292.824 1432100.494 15.371

0.000400 0.001225 0.024025 13 603834.872 1431936.270 184.014

0.001764 0.000121 0.002025 14 616372.889 1432122.107 244.108

0.001849 0.000049 0.000001 15 636014.837 1431887.042 454.080

0.004761 0.000576 0.000256 16 585112.507 1439043.854 26.971

0.000049 0.000400 0.015625 17 603268.411 1438806.099 66.465

0.000676 0.000036 0.017161 18 616959.104 1439852.723 270.854

0.000484 0.000144 0.000169 19 632871.392 1438211.714 466.612

0.002116 0.000000 0.001521 20 582297.458 1446604.849 27.625

0.001936 0.004356 0.011449 21 603048.535 1446878.371 134.153

0.000001 0.000900 0.000256 22 616151.898 1446066.862 203.347

0.007225 0.000144 0.020736 25 590052.609 1453287.038 47.545

0.007225 0.000144 0.020736 26 581570.993 1454693.541 12.540

0.007396 0.008281 0.000081 27 604754.261 1454354.333 56.787

0.000441 0.009216 0.005184 28 619687.853 1453214.976 216.889

0.001296 0.000784 0.003600 29 633997.693 1453956.534 295.369

0.003481 0.000100 0.007744 30 582466.867 1461370.231 17.867

0.000324 0.000900 0.000400 31 588765.316 1462447.370 13.019

0.002500 0.001444 0.022801 32 599319.038 1461110.504 43.136

0.002116 0.000961 0.000036 33 602964.067 1461316.735 19.090

0.010201 0.000625 0.022201 34 616373.186 1461146.415 122.253

0.000961 0.000169 0.018769 35 634632.941 1461235.358 228.301

0.002704 0.002304 0.017424 36 582332.907 1466589.801 12.125

0.000169 0.001369 0.000729 37 591852.440 1468979.793 19.091

0.010201 0.008281 0.021609 38 604100.658 1468384.691 43.051

0.000576 0.000576 0.027225 39 620026.692 1467765.333 62.665

0.000529 0.002601 0.000784 40 635924.117 1468981.177 252.726

0.010816 0.001521 0.032761 41 586521.948 1471743.655 11.853

0.000081 0.000576 0.003969 42 587961.045 1477246.633 19.141

0.004900 0.000441 0.000196 43 598096.300 1475842.847 14.365

0.000025 0.004624 0.003969 44 608960.386 1476561.778 28.847

0.000289 0.000256 0.023104 45 620847.595 1476378.036 49.735

0.003721 0.008649 0.003364 46 636448.507 1476147.279 155.445

0.001936 0.002025 0.026896 47 589248.591 1483232.716 23.352

0.004761 0.012544 0.017161 48 598125.521 1483577.313 6.848

0.002401 0.000049 0.001024 49 608026.336 1483720.565 12.224

0.000004 0.003364 0.002500 50 616016.456 1483626.350 51.488

0.000625 0.000441 0.002704 51 633838.004 1482290.904 126.620

0.001764 0.011236 0.013225 52 625420.752 1432265.016 372.368

SUM 0.107370 0.122114 0.470377

RMSE 0.045 0.048 0.095

RMSE N E Elev.NAVSTAR vsNAVSTAR/GLONASS (n = 52) 0.045 0.048 0.095

Project vs VRS (n = 12) 0.035 0.088 0202



• 2005 research conclusions– Investigate stations at 8 km, 14 km 18 km– Re-observe stations during specific optimum satellite

availability and geometry conditions– Time does not appear to affect accuracy– Can achieve sub-2 cm accuracy out to 20 km

• 2007 research conclusions– No clear degradation over distance– RMSE reveals vertical to be 2x less accurate than horizontal– Successful methodology for small scale mapping projects

PAMAP QA Surveys Evolution


Image 1. Bare earth Image 2. High Grass, Image 3. Brush lands Image 4. Fully Image 5. Urban Areas 0.0 m and low grass < 0.15m weeds and crop ≤ 1.5m and low trees ≤ 2.0m forested > 2.0m


PAMAP QA Surveys Evolution

• First Phase (2007-2008)– OPUS control– Point-to-point wireless RTK (~90%)– Static Baselines (~10%)

• Second Phase (2009-2010)– RTN (VRS network and point solutions)

PAMAP Phase 1

• PAMAP Orthophotography 2005-2007


PAMAP Phase 1

• PAMAP LIDAR 2006-2007


PAMAP Phase 1


• Relied on Wireless RTK– Utilized Airlink CDMA modems– Verizon wireless – Job required surveying random points over large areas – RTN network not yet developed in the project area– Used OPUS for control at base locations

PAMAP Phase 1


Phase 1 Methodology

• Project area was broken into blocks• Two independent one person teams• Both team members set up an RTK base at

a pre-chosen location• For redundancy, each survey point was

observed twice using a baseline vector from each control point

• The two sets of coordinates were averaged in the office via Excel spreadsheet


Phase 1 Methodology


PAMAP Phase 1

• Advantages of Wireless RTK– Range only limited by satellite/atmospheric conditions– Allows user input/control– No subscription fees other than wireless plan– CDMA format more available in rural areas


PAMAP Phase 1

• Disadvantages of Wireless RTK– Requires user to visit base location– Possibility of theft if base left unattended– Possibility of user errors in processing base data– Hardware intensive– CDMA modems were not designed for outdoor use

Succumbed to disadvantages to realize efficiencies in field work production

(Static networks and radio-based RTK are cost prohibitive)


PAMAP Phase 2 2009-2010


PAMAP Phase 2

• QA/QC of 2008 Orthos (second generation) and 2008 LIDAR

• Reduction of checkpoints density due to funding restraints

• Well established VRS network at this time


VRS Network (KeyNet)


Phase 2 Methodology

• Primarily a single one person crew• Checkpoints were observed twice with a

different initialization each time• OPUS RS was used to process static

observations where data service was unavailable

• Some points were also observed with OPUS RS (Rapid Static) for quality control


PAMAP Phase 2

• Advantages of VRS– Eliminates base station setup/teardown time– No risk of base theft– Eliminates major sources of user error– Less hardware intensive– Built in redundancy “network solution”– Real time results with little post processing


PAMAP Phase 2

• Disadvantages of VRS– Requires monthly access fee– Little user input– Data interruptions due to server failure-Rare

Advantages outweigh disadvantages


VRS and OPUS RS Comparison

VRS OBSERVATIONS OPUS RS OBSERVATIONS

FIRST OBSERVATION MINUS SECON OBSERVATION

FIRST OBSERVATION MINUS SECON OBSERVATION SQUARED

PA SPC NAD 83 (1986) U.S. Survey Ft. NAVD 88 PA SPC NAD 83 (1986) U.S. Survey Ft. NAVD 88 U.S. Survey Ft. U.S. Survey Ft.

POINT # NORTHING EASTING ELEVATION NORTHING EASTING ELEVATION NORTHING EASTING ELEVATION NORTHING EASTING ELEVATION

B5068 465584.18 2330767.9 1387 465584.2 2330767.99 1386.94 -0.020 -0.090 0.060 0.000400 0.008100 0.003600

C5082 553938.41 2396797.34 1701.3 553938.47 2396797.45 1701.22 -0.060 -0.110 0.080 0.003600 0.012100 0.006400

C5093 465324.88 2426403.12 541 465324.97 2426403.13 540.96 -0.090 -0.010 0.040 0.008100 0.000100 0.001600

C5100 498579.48 2453666.97 555.5 498579.5 2453667 555.51 -0.020 -0.030 -0.010 0.000400 0.000900 0.000100

H5066 443110.58 2335720.27 508.1 443110.6 2335720.24 508.19 -0.020 0.030 -0.090 0.000400 0.000900 0.008100

O5080 540091.04 2396946.27 1366.7 540090.93 2396946.25 1366.82 0.110 0.020 -0.120 0.012100 0.000400 0.014400

O5085 564739.51 2412083.47 973.8 564739.5 2412083.41 973.86 0.010 0.060 -0.060 0.000100 0.003600 0.003600

O5104 547244.81 2454785.23 1161 547244.77 2454785.19 1161.08 0.040 0.040 -0.080 0.001600 0.001600 0.006400

SC-14H 470150.16 2446545.95 467.6 470150.15 2446545.9 467.69 0.010 0.050 -0.090 0.000100 0.002500 0.008100

SC-2H 574819.38 2453404.08 1751.7 574819.3 2453404.11 1751.59 0.080 -0.030 0.110 0.006400 0.000900 0.012100

SC-3H 541385.39 2411133.33 1184.6 541385.32 2411133.42 1184.51 0.070 -0.090 0.090 0.004900 0.008100 0.008100

SC-5H 510910.45 2369256.07 1657.5 510910.42 2369256.06 1657.38 0.030 0.010 0.120 0.000900 0.000100 0.014400

SUM 0.013900 0.039300 0.086900

RMSE 0.034 0.057 0.085


What’s Next?


Nebraska USDA LIDAR QA/QC

• 3400 square mile project area• 300 checkpoints• Used a combination of VRS and static GPS• OPUS used as a check on VRS outside of

the network– Longest VRS baseline- 47.5 Miles– ΔH .036 ΔV .029



Questions & Discussion

Contact:

• Eric Orndorff at [email protected]

• Zach Lupold at [email protected]

mailto:[email protected]

mailto:[email protected]

© 2009 herbert, rowland & grubic, inc. opus and vrs for qa surveys of the pamap program eric m....

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