THE EARTHS SURFACE IS CHANGING - wsrn3.org An epoch is a moment in time used as a ... P702 DH5822 -251552.377 1258015.478 4284.952 P702 DH5822 -251552.178 1258015.588 4284.949 -0.199

THE EARTHS SURFACE IS

CHANGING

Hyndman and Wang,

1994

Vertical Motion Associated with Subduction

Positioning America for the Future

NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION

National Ocean Service

National Geodetic Survey

Horizontal velocities in the western U.S. relative to the North American Datum of 1983 as derived from geodetic observations.

Slide from R. Snay, NGS

-Times 8 years (2002-2010) -As will be seen realized with NAD 83(2011)Epoch2010 (tent. name)

THE PROJECT

CONUS Conterminous United States

CORS Continuously Operating Reference Stations

FGDC Federal Geographic Data Committee

GNSS Global Navigation Satellite System

GPS Global Positioning System

HTDP Horizontal Time Dependent Positioning

(NGS

software)

IGS International GNSS Service

MYCS Multi-Year CORS Solution

Epoch An epoch is a moment in time used as a

reference point.

NA2011 National Adjustment of 2011

NAD 83 North American Datum of 1983

NAVD 88 North American Vertical Datum of 1988

NADCON North American Datum Conversion (NGS

software) NGS National Geodetic Survey

NGSIDB National Geodetic Survey Integrated Data

Base

OPUS Online Positioning User Service

Original realization completed in 1986

◦ Consisted (almost) entirely of classical

(optical) observations

“High Precision Geodetic Network”

(HPGN) and “High Accuracy Reference

Network” (HARN) realizations

◦ Most done in 1990s, essentially state-

by-state

◦ Based on GNSS but classical stations

included in adjustments

National Re-Adjustment of 2007

◦ NAD 83(CORS96) and (NSRS2007)

◦ Simultaneous nationwide adjustment

(GNSS only)

New realization: NAD 83(2011) epoch

2010.00

Multi-Year CORS Solution (MYCS)

◦ Reprocessing of all CORS GPS data 1994-present

◦ 2264 CORS & global stations

◦ NAD 83 computed by transformation from IGS08

National Adjustment of 2011 (NA2011)

◦ New adjustment of GNSS passive control

◦ GNSS vectors tied (and constrained) to CORS

NAD 83(2011) epoch 2010.00

◦ Approximately 80,000 stations and

400,000 GNSS vectors

Realization SAME for CORS

and passive marks

This is NOT a new datum! (still NAD 83)

The project is officially called the “National Adjustment of 2011”, abbreviated as NA2011. It is a nationwide, geometric adjustment of passive stations with positions determined using Global Navigation Satellite System (GNSS) technology and data, which includes the Global Positioning System (GPS).

NA2011 is called “geometric” because it will yield new values for latitude, longitude, and ellipsoid height; it will NOT affect the orthometric heights of stations. However, a future nationwide vertical adjustment is being considered to determine GNSS-derived orthometric heights based on the results of NA2011

NAD 83(2011) epoch 2010.00

◦ “2011” is datum tag year adjustment complete

◦ “2010.00” is “epoch date” (January 1, 2010)

Date associated with coordinates of control station

◦ Frame fixed to North American tectonic plate

Includes California, Puerto Rico, and US Virgin

Islands

NAD 83(PA11) epoch 2010.00

◦ Frame fixed to Pacific tectonic plate

NAD 83(MA11) epoch 2010.00

◦ Frame fixed to Mariana tectonic plate

There has been no datum change, that is, the origin,

scale and orientation of NAD 83(2011) are identical

to those of NAD 83(CORS96). The changes in

coordinates are driven by multiple factors including

the switch to absolute antenna calibrations,

new/revised processing algorithms, improved

discontinuity identification, longer data sets, and our

improved definition of the global reference frame.

However for the end user the biggest change is

caused by the new reference epoch, which has

changed by 8 years from 2002.00 to 2010.00.

CORS

Current

ITRF2000 1997.00

NAD83(CORS96) 2002.00

Relative antenna calibration

ITRF2000, defined by only 8 global stations

Upcoming

IGS08 (2011) 2005.00 NAD83(2011) 2010.00 Absolute ITRF2008 uses ~230

stations What does this all

mean?

Average differences of NAD 83(2011) epoch 2002.00 minus NAD 83(CORS96) epoch 2002.00: East -0.18 1.86 cm; North 0.14 1.07 cm; Vertical 0.17 2.11 cm

< 2 mm +/- 1-2 cm (nationally)

The National Geodetic Survey (NGS) operates the Continuously Operating Reference Station (CORS) Network that provides Global Navigation Satellite System (GNSS) data in RINEX format, and associated positions.

Currently NGS provides these coordinates in ITRF00 epoch 1997.00, and in NAD 83(CORS96) epoch 2002.00.

NGS has completed a full reanalysis of all data from CORS and a set of global sites with the goal to compute a fully consistent set of coordinates, GPS satellite orbits and Earth Orientation Parameters (EOP).

This initial Multi-Year CORS (MYCS1) effort is the first of a series reprocessing projects that will occur periodically in the coming years.

Slide by J. Griffiths and the MYCS Team

REGIONAL CORS NETWORK

NAD 83 CORS 96 VS NAD 83 2011

WASHINGTON NORTH ZONE

US FEET

NAD 83/CORS 96 US FT NAD 83 2011 US FT DIFFERENCE US FT

NAME PID# NORTHING EASTING ELLIPSE NAME PID# NORTHING EASTING ELLIPSE NORTH EAST ELLIPSE

BREW DK4088 414845.879 1921406.779 784.149 BREW DK4088 414845.921 1921406.848 784.093 -0.042 -0.069 0.056

CHWK DE6569 788881.079 1359188.777 571.226 CHWK DE6569 788881.146 1359188.871 571.948

CPXF AJ7202 -55042.405 1284192.490 1751.883 CPXF AJ7202 -55042.245 1284192.667 1751.899 -0.160 -0.177 -0.016

CHZZ AJ6959 -535726.824 833266.454 168.880 CHZZ AJ6959 -535726.552 833266.744 167.851 -0.272 -0.290 1.029

FTS1 AF9545 -274022.816 849551.966 -44.718 FTS1 AF9545 -274022.546 849552.318 -44.646 -0.270 -0.352 -0.072

FTS2 AF9580 -273923.323 849576.945 -43.943 FTS2 AF9580 -273923.072 849577.266 -43.907 -0.251 -0.321 -0.036

FTS5 DK4499 -274022.791 849551.990 -44.173 FTS5 DK4499 -274022.521 849552.339 -44.108 -0.270 -0.349 -0.065

FTS6 DK3581 -273923.320 849576.946 -43.422 FTS6 DK3581 -273923.055 849577.275 -43.373 -0.265 -0.329 -0.049

GOBS AF9664 -423645.214 1645179.516 2040.567 GOBS AF9664 -423645.139 1645179.585 2040.534 -0.075 -0.069 0.033

GWEN AF9636 -443744.277 1514229.524 2403.919 GWEN AF9636 -443744.124 1514229.675 2403.890 -0.153 -0.151 0.029

GWN2 AF9643 -443746.490 1514308.274 2406.285 GWN2 AF9643 -443746.355 1514308.397 2406.252 -0.135 -0.123 0.033

GWN5 DJ6121 -443744.221 1514229.564 2404.483 GWN5 DJ6121 -443744.122 1514229.685 2404.464 -0.099 -0.121 0.019

GWN6 DJ6123 -443746.450 1514308.281 2406.869 GWN6 DJ6123 -443746.359 1514308.393 2406.846 -0.091 -0.112 0.023

KELS AF9666 -314694.576 1117084.743 -50.840 KELS AF9666 -314694.388 1117084.921 -50.866 -0.188 -0.178 0.026

LIND AH2504 261.556 1713998.210 1549.843 LIND AH2504 261.653 1713998.306 1549.787 -0.097 -0.096 0.056

LINH CQ6015 261.574 1713998.230 1551.021 LINH CQ6015 261.665 1713998.325 1550.925 -0.091 -0.095 0.096

LNGB DG6523 85788.826 1162069.017 9.173

NEAH AF9672 496151.473 717895.152 1509.912 NEAH AF9672 496151.681 717895.528 1509.987 -0.208 -0.376 -0.075

ORS1 DG8527 -1029690.810 2107110.801 4718.258 ORS1 DG8527 -1029690.707 2107110.869 4718.232 -0.103 -0.068 0.026

ORS2 DG9793 -1029728.650 2107192.799 4721.195 ORS2 DG9793 -1029728.562 2107192.878 4721.165 -0.088 -0.079 0.030

P020 DG7408 9140.160 2206207.497 1576.657 P020 DG7408 9140.208 2206207.533 1576.608 -0.048 -0.036 0.049

P376 DH4503 -742618.354 1052121.428 594.572 P376 DH4503 -742618.135 1052121.510 594.602 -0.219 -0.082 -0.030

P415 DH4093 -111803.037 913011.487 -49.511 P415 DH4093 -111802.800 913011.716 -49.478 -0.237 -0.229 -0.033

P420 DG8344 -143324.545 1129161.185 244.261 P420 DG8344 -143324.352 1129161.331 244.284 -0.193 -0.146 -0.023

P432 DG8347 -136402.233 1426805.798 1047.426 P432 DG8347 -136402.103 1426805.893 1047.409 -0.130 -0.095 0.017

P446 DK4151 -315634.274 1117892.591 -52.861 P446 DK4151 -315634.064 1117892.688 -52.802 -0.210 -0.097 -0.059

P451 DH4096 -70363.590 2089344.223 1154.473 P451 DH4096 -70363.539 2089344.249 1154.424 -0.051 -0.026 0.049

P687 DH9589 -321032.573 1254367.701 1284.269 P687 DH9589 -321032.425 1254367.795 1284.308 -0.148 -0.094 -0.039

P690 DH4120 -296125.448 1296628.609 6821.650 P690 DH4120 -296125.277 1296628.710 6821.745 -0.171 -0.101 -0.095

P693 DH5819 -285003.908 1293663.172 6933.536 P693 DH5819 -285003.732 1293663.345 6933.546 -0.176 -0.173 -0.010

P695 DH5847 -289308.201 1303249.866 6614.226 P695 DH5847 -289307.972 1303249.920 6614.242 -0.229 -0.054 -0.016

P696 DH4123 -290131.354 1306422.834 5250.531 P696 DH4123 -290131.165 1306422.956 5250.577 -0.189 -0.122 -0.046

P697 DH4126 -293392.313 1300037.596 7266.872 P697 DH4126 -293392.040 1300037.560 7266.879 -0.273 0.036 -0.007

P698 DH4129 -298634.470 1304001.714 4854.764 P698 DH4129 -298634.306 1304001.832 4854.803 -0.164 -0.118 -0.039

P699 DH5850 -292492.542 1293307.460 7462.108 P699 DH5850 -292492.346 1293307.597 7462.157 -0.196 -0.137 -0.049

P702 DH5822 -251552.377 1258015.478 4284.952 P702 DH5822 -251552.178 1258015.588 4284.949 -0.199 -0.110 0.003

PABH AF9668 95972.772 802761.354 43.543 PABH AF9668 95973.071 802761.793 43.560 -0.299 -0.439 -0.017

PRDY DF8479 147833.033 1200504.755 271.876

RPT1 AF9503 145173.775 1258597.959 -31.299 RPT1 AF9503 145173.885 1258598.146 -31.345 -0.110 -0.187 0.046

RPT2 AF9608 145064.667 1258536.193 -31.217 RPT2 AF9608 145064.798 1258536.364 -31.214 -0.131 -0.171 -0.003

RPT5 DK4179 145173.782 1258597.956 -31.010 RPT5 DK4179 145173.934 1258598.131 -31.024 -0.152 -0.175 0.014

RPT6 DK4105 145064.693 1258536.231 -30.925 RPT6 DK4105 145064.845 1258536.352 -30.922 -0.152 -0.121 -0.003

SC00 AJ7205 -17884.342 1667579.033 3867.427 SC00 AJ7205 -17884.269 1667579.178 3867.427 -0.073 -0.145 0.000

SEAI DH7235 253836.745 1289958.889 -11.772 SEAI DH7235 253836.831 1289959.003 -11.781 -0.086 -0.114 0.009

SEAT AF9674 242038.056 1276633.133 146.578 SEAT AF9674 242038.149 1276633.269 146.542 -0.093 -0.136 0.036

SEAW AH7396 253836.629 1289958.788 -11.831 SEAW AH7396 253836.728 1289958.961 -11.906 -0.099 -0.173 0.075

SEDR AF9670 558073.752 1303451.466 99.245 SEDR AF9670 558073.855 1303451.606 99.219 -0.103 -0.140 0.026

SPN1 AJ1822 207740.648 2482674.988 2363.398 SPN1 AJ1822 207740.684 2482675.044 2363.378 -0.036 -0.056 0.020

SPN2 AJ1824 207748.956 2482760.874 2364.930 SPN2 AJ1824 207749.039 2482760.936 2364.884 -0.083 -0.062 0.046

SPN5 DK3591 207740.634 2482674.977 2364.037 SPN5 DK3591 207740.700 2482675.048 2363.955 -0.066 -0.071 0.082

SPN6 DK3593 207748.954 2482760.878 2365.520 SPN6 DK3593 207749.024 2482760.940 2365.441 -0.070 -0.062 0.079

THUN DF8481 42032.813 1278030.065 468.759

TWHL AJ7208 12877.099 1119176.832 353.116 TWHL AJ7208 12877.243 1119177.032 353.110 -0.144 -0.200 0.006

WHD1 AF9502 484328.157 1187173.606 46.447 WHD1 AF9502 484328.293 1187173.748 46.329 -0.136 -0.142 0.118

WHD2 AF9613 484228.422 1187171.084 35.856 WHD2 AF9613 484228.583 1187171.254 35.758 -0.161 -0.170 0.098

WHD5 DK4111 484328.150 1187173.622 46.847 WHD5 DK4111 484328.284 1187173.754 46.762 -0.134 -0.132 0.085

WHD6 DK4113 484228.441 1187171.106 36.322 WHD6 DK4113 484228.557 1187171.229 36.247 -0.116 -0.123 0.075

YELM DF8477 -13610.612 1197709.053 270.177

ZSE1 DF4068 107646.887 1304118.427 269.032 ZSE1 DF4068 107646.997 1304118.624 269.022 -0.110 -0.197 0.010

Why is NGS doing a national adjustment

a mere 4 years after the last adjustment

How will it be done? ◦ longer data spans

◦ absolute antenna calibrations

satellite transmitting and ground receiving antennas

◦ new network design—added redundancy

Delaunay triangulation over global sites and CORS backbone

tie remaining CORS to backbone as stars

◦ IERS 2003 Conventions generally implemented

◦ updated model for station displacements due to ocean tidal loading

◦ updated models for troposphere propagation delays

◦ use current frame; first attempt to obtain a full history of products in a fully consistent framework.

Contribute NGS reprocessed orbits, to International GNSS Service)

Slide by J. Griffiths and the MYCS Team

In order for the coordinates of passive stations to maintain consistency with the CORS’ representation of the NSRS, NGS will be doing another national adjustment this year

The datum tag that will be adopted for both CORS (active) and passive is NAD83(2011)

CORS (only) will be the control for the LSA

For NGS products and services to be mutually

aligned, it is necessary to perform an adjustment

(constrained to the new MYCS coordinates) of as

many GNSS vectors held in the NGS Integrated Data

Base (NGSIDB) as possible.

These vectors represent GNSS observations

between passive stations, and, importantly, between

passive stations and CORS (i.e., active stations).

The vectors tied to CORS will make it possible to

determine new coordinates on passive control that

are consistent with the MYCS.

All CORS with GNSS data archived by NGS were

included in the MYCS. The only CORS not included

are those that have no archived data, which consists

only of a small number of Cooperative CORS.

Of these, the only ones excluded were

decommissioned prior to becoming part of the NGS

CORS network and did not provide their historic

GNSS data to NGS. The Cooperative CORS

program is no longer in effect, and so all currently

operating CORS are simply “CORS”, and they are all

included in the MYCS. A list of previously operating

CORS that were not used in the MYCS will be

provided in the near future.

NGS is in the process of readjusting most, if not all,

of the passive vector control in the NGSIDB to make

it consistent with MYCS1 solution.

The results of this adjustment (National

Readjustment of 2011) will have the same reference

frame tag and epoch date as the MYCS1, namely

NAD 83(2011) epoch 2010.00.

A passive station is, in NGS terminology, a

conventional” ground station, e.g., a brass disk set in

a substantial structure, a steel rod driven vertically into

the ground until refusal, or other such stable physical

marks that can be occupied with survey equipment.

An active station is a GNSS antenna (and

associated receiver) in a fixed location providing

GNSS data to the public, such as a CORS,WSRN

GNSS observations (vectors) for all passive control stations in the

NGS Integrated Data Base (NGSIDB) connected (directly or indirectly)

to CORS with MYCS coordinates as of July 31, 2011 may be included

in the adjustment.

However, being “included in the adjustment” only assures that the

observations will be evaluated for their possible inclusion in the final

adjustment. As with any survey control network adjustment,

observations that do not “fit” well with other observation (i.e.,

“outliers”) will be rejected.

In some cases, this may result in passive control stations being

excluded from NA2011, in which case they will retain their previous

datum tag. Projects submitted after July 31, 2011 will be published

with NAD 83(NSRS2007) coordinates until NA2011 is completed. At

that time those projects in the queue will be adjusted to the new

realization and published on NAD 83(2011) epoch 2010.00.

Any passive station that does not have acceptable GNSS data will be excluded from NA2011, as will stations that are not (directly or indirectly) connected to a CORS in the MYCS.

For passive stations meeting these criteria, NGS intends to provide NAD 83(2011) epoch 2010.00 coordinates everywhere that is appropriate and can be determined accurately with respect to the MYCS.

This will include the conterminous US (CONUS) and Alaska, and it may include other locations outside CONUS as well. The decision as to what additional areas to include will be made during the course of the project. Stations not included in NA2011 will continue to have their positions referenced to the same datum realization used for current survey control prior to NA2011 (as indicated by the datum tag on NGS datasheets).

The answer is entirely dependent upon whether an

acceptable GNSS survey is ever performed at that

passive control mark. For non-GNSS (i.e.,

“classically” determined) control, the most accurate

way to determine coordinates consistent with a

modern realization of NAD 83 is to resurvey it using

geodetic quality GNSS data.

The intended use of this position will determine

whether an OPUS solution is sufficient or if a

complete GNSS survey submitted to NGS for

publication is required.

First, consult with NGS through the appropriate personnel or NGS headquarters personnel to ensure your project meets NGS requirements for projects performed during this time frame.

When performing the constrained adjustments, unless advised differently by NGS personnel, hold NAD 83(NSRS2007) coordinates for all published passive control and NAD 83(CORS96) coordinates for all CORS in the survey.

The same approach for constraining a survey should also be used for projects submitted to NGS that will be included in NA2011 (i.e., before the cut-off date).

Yes, those stations will have network and local accuracies computed and published along with the NAD 83(2011) epoch 2010.00 coordinates.

As with the NA2011 project itself, these accuracies will be provided in centimeters, and at the 95% confidence level in accordance with the Federal Geographic Data Committee (FGDC) Geospatial Positioning Accuracy Standards, Part 2

Based on the MYCS results, the average expected change is about 2

cm horizontally and 1 cm vertically (i.e., ellipsoid height).

However, these changes – especially the horizontal changes – vary

significantly. In addition, the largest part of the horizontal change is

due to time difference (velocity), especially in tectonically active

areas, such as California; when brought to a common time (2002.00),

the average horizontal change decreases to 0.2 cm.

A list of coordinate changes, from NAD 83(NSRS2007) epoch 2002.00

to NAD 83(2011) epoch 2010.00 will be provided to the public.

For the purposes of transforming the official coordinates of each geodetic control point, NGS will not create a transformation model. An interpolative transformation tool, like NADCON, functions only to apply gross consistent regional shifts to entire areas.

NGS will certainly examine the shifts in coordinates for such behavior, but the shifts in going to NAD 83(2011) from NAD 83(NSRS2007) are not expected to significantly exceed the formal errors of those shifts, nor are they expected to all move in one consistent direction regionally.

NGS does not endorse the idea of applying a simple interpolative tool to all surveys and maps in a region, as they each will have their own unique connections to surrounding geodetic control. Although NGS will look at all possibilities, there is already compelling evidence that a singular transformed dataset will have very limited applications, and may actually be highly misleading. This is especially the case as the size of the area and required spatial accuracy increase.

Good agreement with IGS type means

Pending approval from International GNSS Service (IGS)

9/23/2010 ION GNSS 2010 45

RESULTS

Diagram shows plots of average error for 5 points constrained for each of the three realizations. The MYCS coordinates fit the baselines observed much better than the other two.

• OPUS-Static – U.S. CORS Network – Fixed IGS ephemerides

– Computes independent double differenced baseline solutions between the unknown and 3 CORS

– Relative antenna models – Phase ambiguity integer

fixing – Relative troposphere

modeling – ITRF2000 reference

frame – Average position

solution – Peak – Peak error

reported

• OPUS-Net

– U.S. CORS Network & IGS Global Network

– Network approach

– Consists of 3 nearby CORS + up to 12 CGPS from global IGS network

– Absolute antenna models

– SV & ground

– Ocean tidal loading model

– Satellite weighting

– Relative troposphere modeling

– ITRF2008 reference frame

– Weighted least squares adjustment

– Weighted mean and standard deviations reported at 95%

OPUS-net info. From Dr. Neil Weston

WHAT ABOUT THE WSRN?

HTDP v 3.1

The “epoch” is the date associated with the coordinates of a control station. An epoch is a necessary part of a complete datum or reference frame name because coordinates can change with time (i.e., they may have non-zero velocities relative to some chosen, stable coordinate reference). For NA2011, the positions will be referenced to midnight January 1 of 2010 (epoch 2010.00). NGS has provided epoch dates for CORS and related products (such as OPUS) for many years, and for passive marks included in the 2007 national readjustment. This practice will continue for NA2011, and it will become more prevalent and consistent throughout NGS. Typically the epoch date is displayed with two decimal places.

Users should be aware that if the velocity of a station is known, then its position can be computed at different epochs; thus one datum tag can have multiple epochs. However, the accuracy of the computed position will depend on the accuracy of the velocity, which varies by station and location. Epoch dates on some stations may also change without changing the datum tag if a local episodic event (such as an earthquake) occurs that requires a local adjustment to determine new positions. In summary, epoch dates are needed to accommodate the precision of GNSS measurements and to recognize the dynamic nature of the Earth and its effect on coordinates.

Interactively estimate displacements between two dates.

Individual points entered interactively or

Points on a specified grid

Select NAD83(CORS96) or NAD83(NSRS2007)

Select the dot for Deci-year format

GRAVITY - GEOID12

New hybrid geoid model (likely “GEOID12”) ◦ Use NAD 83(2011) epoch 2010.00 ellipsoid heights on

NAVD 88 benchmarks

◦ Might also use OPUS-Database results on NAVD 88 BMs

May perform national vertical adjustment ◦ Constrain vertically to NAVD 88 benchmarks

Perform as simultaneous nationwide adjustment

◦ GNSS-derived orthometric heights

NAD 83(2011) ellipsoid heights with GEOID12

NOT a readjustment of NAVD 88 leveling

The GPS era brought fast, accurate ellipsoid heights – naturally this drove a desire for fast, accurate orthometric heights ◦ 1-2 cm accuracy is needed

Leveling the country can not be done again ◦ Too costly in time and money

Leveling yields cross-country error build-up

Leveling requires leaving behind marks ◦ Bulldozers and crustal motion do their worst

Yes, a new hybrid geoid model (GEOID12) will be produced.

Preliminary activities in this regard are currently underway.

Development of this model requires completion of NA2011 first;

hence it cannot be delivered coincidentally with NA2011

results.

As is obvious from the model name, NGS expects to deliver the

model in 2012.

As with NA2011, completion of the project will be determined

by meeting quality and completeness criteria.

Possibly. NGS is currently investigating the need

and feasibility of performing a nationwide vertical

adjustment of all GNSS-derived orthometric heights

in the NSRS. If performed, the GNSS-derived

orthometric heights determined for all stations in the

vertical adjustment will be consistent with NAD

83(2011) epoch 2010.00 and GEOID12, and they will

be referenced to the North American Vertical Datum

of 1988 (NAVD 88).

SCHEDULE

December 14, 2011. Finalize modified version of ADJUST and associated

project

adjustment user guidelines.

January 2, 2012. SDD performs IDB load.

o Final NAD 83(2011) epoch 2010.0 adjusted coordinates and accuracies for

passive marks

o Final NAD 83(2011) epoch 2010.0 adjusted coordinates and accuracies for

CORS

January 13, 2012. Determine final constrained NAD 83(PA11) and

(MA2011)

epoch 2010.0 adjusted coordinates (i.e., referenced to Pacific and Mariana

tectonic

plates)

o Delivered to SSD and loaded into NGSIDB

o Provide to Geoid Team to develop GEOID12 for Hawaii, American Samoa,

Guam, and CNMI.

January 31, 2012. NA 2011 final report submitted.

o Posted to NA2011 web page,

o Public announcement that adjustment is entirely complete

o Project closeout.

o NOTE: Loading of projects submitted after August 31, 2011 cutoff date will

continue beyond project closeout date if necessary.

February 15, 2012 ? . Projected delivery date for release of GEOID12 and

publication

of NAD 83(2011) epoch: 2010.00 coordinates. The release date of GEOID12 is

assumed, for the purposes here, to be February 15, 2012, but could easily vary

from

that date. Additionally, if there is a significant delay in the release of GEOID12 it

may be decided to release data sheets with NAD 83(2011) epoch 2010.00

coordinates

prior to delivery of GEOID12.

o Public Announcement that NAD 83(2011) epoch 2010:00 data sheets are

available

o Formal announcement submitted for publication in Federal Register

April 15, 2012. Cutoff date for projects

constrained to NAD 83 (NSRS2007).

Note this date is tentative as it is actually

determined as two months from release of

GEOID12 and the release of data sheets with

NAD 83(2011) epoch 2010.00 coordinates.

WSRN

Primary (New) Server will Operate in

NAD 2011 Beginning June 2011

Secondary (Legacy) Server will continue to

Operate in NAD 83 CORS 96 Epoch 2002.00

for at least one year (likely indefinitely)