The City of Oklahoma CityThe City of Oklahoma City

Public Works DepartmentSurvey Section

2008

Plans for the City of Oklahoma City’s Control Network

You have done your research well.You have done your research well.

You have found some good, reliable control near your project. In effect, You have found some good, reliable control near your project. In effect, you have now calibrated or reduced your survey to the datum of this you have now calibrated or reduced your survey to the datum of this

control. control.

But what datum is it?But what datum is it?

DO YOU KNOW THE DATUM DO YOU KNOW THE DATUM OF YOUR CONTROL?OF YOUR CONTROL?

NAD 83?

CORS 96?

NGVD 29?

NAVD 88?

ITRF00????WGS 84?

Is the Is the sourcesource (input) datum labeled? (input) datum labeled?

Is it labeled correctly?Is it labeled correctly?

Is your Is your outputoutput datum labeled? datum labeled?Unknown or incorrectly labeled input datum=Unknown or Unknown or incorrectly labeled input datum=Unknown or

incorrect output datum.incorrect output datum.

OKC’s PRIMARY CONTROLOKC’s PRIMARY CONTROLData SheetData Sheet

The City of Oklahoma’s Primary Control Network was

established in 1990 by Atlantic Aerial Surveys, Ltd. While the control network was based on NAD 83 (86) horizontal and NGVD 29 vertical datum, it was state of the art at the time. For the Vertical datum, Oklahoma City decided to stay with NGVD 29. NAVD 88 was not widely used at the time and most flood studies\maps (FEMA) were in the NGVD 29 datum.

The History of Oklahoma City’s The History of Oklahoma City’s ControlControl

A change of plan was in the works… With the advent of duel frequency GPS, the National Geodetic Survey (NGS)

realized the errors in NAD 83 (86) and NGS was already planning an adjustment to NAD 83 at the inception of Okc’s control network in 1990. We all know it as the High Accuracy Reference Network or HARN (94). They implemented this adjustment in 1994.

By the time of the 94 adjustment, OKC had invested a lot of resources in our Primary Control Network. We developed an extensive GIS system and millions of dollars of infrastructure based on our control. I am sure that those who were aware of HARN (94) must have seen the horizontal shift of approximately 1.5 feet as negligible to a City Wide system that spans 45 miles by 25 miles.

The City of Oklahoma City requires that all projects and new development be referenced to the City’s Primary Control Network, thus creating uniformity in our infrastructure and GIS system.

Horizontal datum is Oklahoma State Plane Coordinates (SPC) NAD 83(86). Although parts of the City extend into the South Zone, all coordinates are projected and reported in the North Zone. The horizontal positional deltas from the current NAD 83 CORS 96 (NSRS 2007) are approximately -0.5 feet in the Northing and -1.5 feet in the Easting.

Vertical datum is in NGVD 29. While, for the most part, OKC’s verticals fit pretty good from point to point, it does not adjust to NAVD 88 very well. This is unexplained and all I can think of is that a lot of these sites weren’t all that GPS friendly and\or maybe Atlantic made some undefined adjustment.

Things to know about the Things to know about the City of Oklahoma City’s City of Oklahoma City’s Primary Control NetworkPrimary Control Network

City of OKC City of OKC Primary Control Primary Control

MapMap

Primary vs. NAD83 (86)

CORS 96 vs. OKC Primary

Sta. No. Vert. Error Sta. No. Vert. Error

200 1.34 455 -0.56218 0.93 456 -0.55161 0.89 402 -0.3099 0.84 457 -0.2929 0.78 458 -0.2745 0.75 401 -0.23

122 0.75 90 -0.22107 0.74 452 -0.22203 0.71 461 -0.19135 0.69 437 -0.17114 0.66 454 -0.1657 0.65 473 -0.16

228 0.64 404 -0.1514 0.62 380 -0.13

101 0.61 435 -0.1348 0.60 439 -0.1366 0.60 438 -0.12

186 0.59 462 -0.10199 0.59 410 -0.0931 0.58 375 -0.07

170 0.58 399 -0.06143 0.57 28 -0.05291 0.57 38 -0.0584 0.55 97 -0.0467 0.54 168 -0.04

124 0.54 43 -0.02187 0.54 132 -0.0283 0.53 470 -0.02

169 0.52 131 -0.0147 0.51

239 0.5185 0.50

294 0.5046 0.4830 0.4787 0.46

117 0.46240 0.4669 0.45

125 0.45150 0.45179 0.45208 0.45209 0.4572 0.4413 0.43

466 0.4310 0.42

126 0.4171 0.40

181 0.39207 0.3911 0.3812 0.3855 0.38

258 0.38127 0.37128 0.37

Primary vs. NAD83 (86)

CORS 96 vs. OKC PrimaryPositional

Sta. No. North ErrorEast Error Error

200 0.98 0.16 0.9914 0.20 -0.95 0.97

161 -0.37 -0.56 0.67294 0.27 -0.48 0.5599 0.00 -0.43 0.43

399 0.40 -0.15 0.4357 -0.38 -0.18 0.4297 -0.35 -0.16 0.3815 -0.15 -0.34 0.3772 0.05 -0.33 0.33

186 0.25 -0.22 0.33107 0.19 -0.27 0.33122 0.13 -0.30 0.33452 0.28 0.16 0.32361 0.32 -0.01 0.32240 0.25 -0.19 0.31199 0.23 -0.19 0.30408 0.14 0.26 0.30187 0.15 -0.25 0.29239 0.20 -0.21 0.29135 0.18 -0.22 0.28401 0.28 -0.01 0.28402 0.27 -0.06 0.2833 -0.03 -0.27 0.2710 0.02 -0.27 0.27

169 0.18 -0.20 0.27473 -0.24 0.12 0.2766 0.11 -0.24 0.26

378 0.25 -0.08 0.2612 -0.03 -0.26 0.2631 0.03 -0.25 0.2517 -0.12 -0.22 0.2511 0.01 -0.25 0.2545 0.08 -0.23 0.2430 0.04 -0.24 0.2447 0.07 -0.23 0.2416 -0.08 -0.22 0.23

114 0.12 -0.20 0.23454 0.23 -0.03 0.23275 -0.02 0.23 0.23170 0.15 -0.17 0.2377 -0.22 -0.05 0.23

335 0.20 -0.10 0.2213 0.01 -0.22 0.2246 0.01 -0.22 0.2280 -0.22 -0.01 0.2284 0.05 -0.21 0.22

350 0.17 -0.13 0.2143 -0.11 0.18 0.2183 0.09 -0.19 0.21

457 0.21 -0.01 0.2181 -0.18 0.10 0.21

307 0.11 0.17 0.20101 0.09 -0.18 0.20357 -0.18 0.09 0.2029 0.00 0.20 0.2048 0.00 -0.20 0.20

203 0.15 -0.13 0.20218 -0.17 -0.10 0.20

Positional Error in the Current Positional Error in the Current Primary ControlPrimary Control

This information was derived by converting the old NAD This information was derived by converting the old NAD coordinates to HARN(94) with NADCON and comparing the result coordinates to HARN(94) with NADCON and comparing the result

with CORS 96. The margin of error is a plus or minus 0.10 feet.with CORS 96. The margin of error is a plus or minus 0.10 feet.

2008 Shift-Worst Vertical

CORS 96 vs. OKC Primary

Sta. No. North Shift East Shift Elev. Shift Sta. No. North Shift East Shift Elev. Shift

455 -0.38 -1.30 -1.10 200 0.36 -1.21 0.91456 -0.46 -1.20 -1.09 161 -0.98 -1.94 0.48457 -0.32 -1.30 -0.84 218 -0.79 -1.47 0.48458 -0.35 -1.31 -0.82 99 -0.61 -1.84 0.44402 -0.29 -1.39 -0.79 29 -0.58 -1.24 0.43452 -0.26 -1.16 -0.74 45 -0.51 -1.66 0.38461 -0.44 -1.22 -0.72 122 -0.47 -1.69 0.36401 -0.29 -1.34 -0.71 107 -0.41 -1.67 0.34437 -0.35 -1.27 -0.71 57 -1.10 -1.67 0.31454 -0.31 -1.34 -0.70 135 -0.43 -1.61 0.29404 -0.37 -1.31 -0.67 14 -0.39 -2.41 0.2790 -0.73 -1.47 -0.66 114 -0.49 -1.61 0.25

435 -0.36 -1.37 -0.66 203 -0.47 -1.52 0.25438 -0.38 -1.32 -0.65 66 -0.49 -1.66 0.22439 -0.53 -1.37 -0.65 31 -0.55 -1.69 0.21473 -0.80 -1.21 -0.64 48 -0.60 -1.65 0.21380 -0.48 -1.45 -0.63 101 -0.52 -1.60 0.20462 -0.42 -1.28 -0.63 228 -0.70 -1.45 0.19410 -0.38 -1.37 -0.61 186 -0.36 -1.58 0.18375 -0.47 -1.49 -0.54 199 -0.39 -1.56 0.16399 -0.18 -1.48 -0.54 67 -0.51 -1.59 0.15381 -0.38 -1.38 -0.51 170 -0.46 -1.55 0.15440 -0.44 -1.30 -0.51 143 -0.47 -1.53 0.14386 -0.41 -1.27 -0.49 47 -0.53 -1.67 0.13367 -0.49 -1.41 -0.47 84 -0.56 -1.64 0.13470 -0.63 -1.33 -0.47 83 -0.52 -1.61 0.12414 -0.53 -1.25 -0.46 187 -0.46 -1.61 0.12448 -0.57 -1.13 -0.46 291 -0.66 -1.38 0.1238 -0.67 -1.56 -0.45 30 -0.54 -1.69 0.11

168 -0.87 -1.41 -0.45 46 -0.59 -1.66 0.10299 -0.65 -1.37 -0.45 169 -0.43 -1.58 0.10397 -0.62 -1.20 -0.45 239 -0.41 -1.55 0.09350 -0.42 -1.47 -0.44 10 -0.55 -1.72 0.08389 -0.46 -1.30 -0.44 13 -0.57 -1.67 0.0897 -1.05 -1.64 -0.43 85 -0.59 -1.54 0.08

413 -0.46 -1.26 -0.43 124 -0.64 -1.52 0.08418 -0.68 -1.15 -0.43 294 -0.33 -1.82 0.08449 -0.61 -1.14 -0.43 11 -0.57 -1.70 0.0428 -0.73 -1.58 -0.42 69 -0.59 -1.56 0.04

131 -0.83 -1.40 -0.42 240 -0.37 -1.54 0.04132 -0.81 -1.45 -0.42 12 -0.61 -1.71 0.03334 -0.70 -1.27 -0.42 87 -0.63 -1.58 0.03384 -0.46 -1.29 -0.42 55 -0.81 -1.34 0.02166 -0.70 -1.47 -0.41 117 -0.56 -1.59 0.02446 -0.56 -1.19 -0.41 72 -0.57 -1.80 0.01363 -0.41 -1.40 -0.40 466 -0.47 -1.40 0.01251 -0.72 -1.36 -0.39189 -0.75 -1.43 -0.38276 -0.64 -1.31 -0.37390 -0.52 -1.29 -0.3727 -0.63 -1.65 -0.36

249 -0.69 -1.41 -0.36365 -0.45 -1.38 -0.36378 -0.32 -1.41 -0.36426 -0.62 -1.14 -0.3643 -0.87 -1.32 -0.3595 -0.80 -1.48 -0.35

349 -0.57 -1.37 -0.3356 -0.84 -1.47 -0.32

2008 Shift-Worst Horiz. Shift

CORS 96 vs. OKC Primary

Sta. No. North Shift East Shift Horz. Shift Elev. Shift

14 -0.39 -2.41 2.44 0.27161 -0.98 -1.94 2.17 0.4857 -1.10 -1.67 2.00 0.3197 -1.05 -1.64 1.95 -0.4315 -0.74 -1.80 1.95 -0.1499 -0.61 -1.84 1.94 0.4472 -0.57 -1.80 1.89 0.01

294 -0.33 -1.82 1.85 0.0833 -0.63 -1.72 1.83 -0.0217 -0.72 -1.68 1.83 -0.2812 -0.61 -1.71 1.82 0.0316 -0.68 -1.68 1.81 -0.2310 -0.55 -1.72 1.81 0.0811 -0.57 -1.70 1.79 0.0431 -0.55 -1.69 1.78 0.2180 -0.95 -1.50 1.78 -0.1630 -0.54 -1.69 1.77 0.1192 -0.77 -1.59 1.77 -0.2827 -0.63 -1.65 1.77 -0.3677 -0.88 -1.53 1.77 -0.2713 -0.57 -1.67 1.76 0.0846 -0.59 -1.66 1.76 0.1041 -0.87 -1.53 1.76 -0.2548 -0.60 -1.65 1.76 0.21

122 -0.47 -1.69 1.75 0.3647 -0.53 -1.67 1.75 0.1328 -0.73 -1.58 1.74 -0.4245 -0.51 -1.66 1.74 0.3884 -0.56 -1.64 1.73 0.1366 -0.49 -1.66 1.73 0.2252 -0.68 -1.59 1.73 -0.2339 -0.69 -1.58 1.72 -0.26

107 -0.41 -1.67 1.72 0.3454 -0.83 -1.50 1.71 -0.2487 -0.63 -1.58 1.70 0.0338 -0.67 -1.56 1.70 -0.4550 -0.64 -1.57 1.70 -0.1556 -0.84 -1.47 1.69 -0.3283 -0.52 -1.61 1.69 0.1279 -0.83 -1.47 1.69 -0.19

154 -0.73 -1.52 1.69 -0.14215 -0.73 -1.52 1.69 -0.1193 -0.75 -1.51 1.69 -0.30

183 -0.75 -1.51 1.69 -0.12117 -0.56 -1.59 1.69 0.02114 -0.49 -1.61 1.68 0.2595 -0.80 -1.48 1.68 -0.35

101 -0.52 -1.60 1.68 0.20110 -0.76 -1.50 1.68 -0.26112 -0.79 -1.48 1.68 -0.29187 -0.46 -1.61 1.67 0.12130 -0.74 -1.50 1.67 -0.2167 -0.51 -1.59 1.67 0.15

218 -0.79 -1.47 1.67 0.4869 -0.59 -1.56 1.67 0.0481 -0.92 -1.39 1.67 -0.24

135 -0.43 -1.61 1.67 0.29109 -0.80 -1.46 1.66 -0.22179 -0.63 -1.54 1.66 -0.01

Coordinate ShiftsCoordinate Shifts

MAP OF MAP OF POSITIONAL POSITIONAL

ERRORERROR

Out with the old and in with the NewOut with the old and in with the New The Public Works Survey Section has completed the process of adjusting the old

Primary Control datum to NAD 83 (CORS 96) for the horizontal datum and NAVD 88 for the vertical datum.

The Survey Section began static GPS sessions on the Primary Control points in November of 2006.

The static sessions were a minimum of 2 hours to 6 hours with our Trimble 4000ssi dual frequency receivers. Two sessions were done on each control point on different days for positional averaging and outliers received a third session. The data from all sessions was processed by NGS’ OPUS.

In November of 2007 the Survey Section upgraded our GPS equipment with Trimble R8 rovers operating on Western Data System’s (WDS) Oklahoma VRS\RTK Network utilizing Trimble RTKNet software. For 3 weeks we tested the VRS\RTK Network against 28 of NGS’ HARN spread across town with amazing results. We have been testing both the VRS\RTK Network and the control ever since.

The addition of the new GPS equipment and the Oklahoma VRS\RTK Network stepped up the pace of data collection on the Primary Control dramatically. The VRS\RTK Network allowed the Survey Section to collect the control points in multiple sessions on multiple days for comparison and averaging. The shear redundancy in data collection gives substantial confidence in the results.

We will officially be making the move to NAD 83\CORS 96 and NAVD 88 in June of this year.

Replacing Destroyed MonumentsReplacing Destroyed Monuments

OKC NEW BRASS OKC NEW BRASS MONUMENTMONUMENT

The The NewNew Primary Control data sheet. Primary Control data sheet.

OKLAHOMA RTK\VRS OKLAHOMA RTK\VRS NetworkNetwork

Oklahoma City Network MapOklahoma City Network Map

Texas VRS\RTK NetworkTexas VRS\RTK Network

The BabysitterThe Babysitter

Stakeout Tolerance Report

Job name: CORS96 CNTRLCHK2

Trimble Survey Controller version: 12.10

Creation date: 2007-11-26

Distance/Coord units: USSurveyFeet

Angle units: DMSDegrees

Stakeout horizontal tolerance: 0.050

Stakeout vertical tolerance: 0.050

Tolerance checking/highlighting: Both

Highlighted values exceed stakeout tolerances.

Name dNorth dEast dElev Code

FJ1358 -0.016 -0.027 -0.048 FJ1358

FJ0820 0.017 0.002 -0.058 FJ0820

FJ0675 0.027 -0.048 0.028 FJ0675

FJ0695 0.032 -0.030 -0.002 FJ0695

FJ0716 N\A (BM only) N\A (BM only) -0.025 FJ0716

Bobby G. Skaggs, P.L.S. Chief Surveyor City Of Oklahoma City 3738 S.W. 15th St., Bld No. 2 Oklahoma City, Ok 73108

Trolling the Oklahoma River BottomTrolling the Oklahoma River Bottom

Hydrographic SurveyingHydrographic Surveying

Setting the Transducer Sit back and survey.

A faster boat!A faster boat!