Improving NGS ProductsNGS Fall Convocation

Holiday Inn – Silver Spring, MD.October 24-28, 2005

Earl F. Burkholder, PS, PENew Mexico State University

Las Cruces, NM 88003

Overview outline - 1

• Introduction

• Mission of NGS

• History of interaction with NGS

• Current status: technology, profession

• Current projects at NMSU

• Spatial data arena

Overview outline - 2

• Relating NGS mission, spatial data arena

• NGS products and services include

• Forward looking opportunities

• Assumptions/consequences

• Thank you

• Questions/discussion

Introduction - EFB

• BS Univ. of Michigan 1973

• 5 years at Commonwealth Associates

• MS Purdue Univ. 1980

• 1980-1993 teach at Oregon Tech.

• Self employed for 5 years

• At NMSU since 1998

• On sabbatical, writing book on 3-D

Mission of NGS• As stated on web site:

“Deliver and evolve the Nation’s foundation of reference for latitude, longitude, height, velocity, (and other things). . .”

• Embraced by all team members?• Challenge for management is to establish

policies and provide leadership that minimizes default sabotage.

History of interaction with NGS

• At Commonwealth, I used NGS control.

• Oregon Tech, we got NGS support.

• Input from NGS for SEWRPC reports.

• At NMSU, work with Advisor Bill Stone.

• As ASCE Journal Editor, I relied upon NGS for reviews and articles.

• Now I’m promoting use of the GSDM.

Status of Science/Profession - 1

• Science/instrumentation, digital and 3-D.• Surveying profession – who are the players?

- ACSM, diversity and reorganization.

- ASCE, focus on engineering applications.

- ASPRS, imaging & spatial info society.

- FIG, international voice for surveying prof’n.

- GITA, represents spatial data users.

- IAG, international voice for geodesy.

Status of Science/Profession - 2

• Surveying program at NMSU:

- Started in 1990 by Dr. James P. Reilly.

- Three faculty; Frank, Wurm, Burkholder.

- Undergrad only, about 40 students.

- Graduates get good jobs; NM & elsewhere

- BLM support is vital. NMSU looking for more.

- Vendors have been very good to program.

(Leica loaned us $240K equipment for a year)

Status of Science/Profession - 3

• Work being done by NGS:

- Readjusting the spatial network.

- Supporting height modernization.

- Coordinating use of CORS.

- Refining services available using OPUS.

- Outreach through state advisors.

- Many others

3-D Projects at NMSU

• NMSU GPS HARN-based network (illustrates network & local accuracy).

• NAVD88 elevation on HARN Station “Reilly” from nearby first-order BMs.

• Support of Texas/NM GPS survey of boundary defined by Rio Grande River

NMSU GPS Network August 2005

Schematic OnlyNo Scale

Crucesair

Reilly

Bromilow

Pseudo

USPA

USPB

1

3

7

5

6

4

2

Description of network adjustment posted at www.zianet.com/globalcogo/magicls.pdf

NAVD88 Elevation on HARN Station “Reilly”

Station "Reilly"A-order HARN

First-order BMStation H-245

First-order BMStation A-245

0 1 km 2 km

Full article can be viewed at www.zianet.com/globalcogo/ReilElev.pdf

Rio Grande River Boundary Area

State Boundary Example

• State boundary between NM and Texas follows Rio Grande River for 25 miles.

• River meanders but boundary was “fixed” by U.S. Supreme Court in 1930 on basis of 1929 survey reconstructing 1852 lines.

• 105 monuments set in distance of 25 miles.• Current project is to GPS the line.• Horizontal record data are NAD27, Vertical

data are NGVD29 (mean sea level).

Mon #90 to Mon #93: Mark to

∆X m ∆Y m ∆Z m Mark Dist.

Record 1241.591 -

430.521 -95.970 1,317.614 m

Observed 1241.509 -

430.477 -96.031 1,317.527 m Diff = -0.087 m or 1:15,144 ∆e m ∆n m ∆u m Hor Dist. Geodetic (3-D) Azi.

Record 1312.820 -

112.287 -1.048 1,317.614 m 94 53 19.26

Observed 1312.729 -

112.329 -1.096 1,317.526 m 94 53 27.03 Diff = 0.048 -0.088 m 7.77 Mon #93 to Mon #94: Mark to

∆X m ∆Y m ∆Z m Mark Dist.

Record 57.258 11.743 44.772 73.627 m Observed 57.096 11.740 44.772 73.501 m Diff = -0.126 m or 1:584 ∆e m ∆n m ∆u m Hor Dist. Geodetic (3-D) Azi. Record 51.533 52.586 0.163 73.627 m 44 25 13.42 Observed 51.379 52.560 0.204 73.501 m 44 20 55.54 Diff = 0.041 -0.126 m -4 17.88

What About Record Accuracy?

• Supreme Court Report values: - Horizontal given to .001 seconds (0.03 m) - Vertical given to 0.001 feet (0.0003 m)• Use those as standard deviations• Input into BURKORD9 • Inverse between points for: - Distance = 73.627 m +/- 0.042 m - Azimuth = 44-25-13.42 +/- 118.9 sec.

Spatial Data Arena is Huge

• ASPRS 10 yr forecast for remote sensing.

• ASPRS Panel Report to USGS on National Orthoimagery Program – comments due by October 24, 2005. see www.zianet.com/globalcogo/asprs-comments.pdf

• Global Spatial Data Infrastructure (GSDI) purpose is international cooperation and collaboration.

Relate NGS Mission to Arena

• Define and support National Spatial Reference System.

• Develop and promote standards.

• Clearing house for implementation of new technology.

NGS Services/Products Include

• CORS – 3D positions and velocities.• OPUS – Automated processing for users.• Height Modernization – geoid modeling.• Standards – Network and local accuracy.• Outreach to: - Other federal agencies - State and local agencies - Professional organizations

Forward Looking Opportunity - 1

• Height – If data from all satellites are used on a deformable Earth, then vertical may turn out to be the strongest component.

- Involves interpolation in radial direction.

- Requires simultaneous data from all GPS satellites to worldwide network.

- GSDM provides appropriate computational environment to do it.

Forward Looking Opportunity - 2

• Ellipsoid height is adopted as elevation.

- Reduces the need for geoid modeling.

- Hydraulic head is not given by orthometric heights.

- Use time analogy with local noon.

• ACSM articles on heights.

• www.zianet.com/globalcogo/elevgsdm.pdf

Forward Looking Opportunity - 3

• Orthophoto map is produced by plotting local differences with respect to origin selected by the user.

- Presumes each pixel has ECEF coordinates and covariance.

- That means raster file is converted to a vector file?

- Totally impractical due to storage req’d?

Assumptions

• Spatial data are digital and 3-D.

• There must be a single origin for 3-D data.

• ECEF geocentric system is foundation.

• Spatial data are obtained from physical observations reduced to components.

• Strict hierarchy for primary/derived data.

• Spatial data accuracy is given by standard deviations – component by component.

Consequences

• Need to make distinction between measurement and observation.

• Need to understand and honor difference between direct & indirect measurements.

• Some spatial data are relative and some are absolute. It makes a difference.

• Local & network accuracy are both legitimate. Local accuracy is based upon storing and using correlation.

Thank you!

• Truly grateful for opportunity to share.

• Sabbatical is going well. Lots yet to do.

• Windows-based BURKORD™ software is coming along. Will be gratis with book.

• Publisher not yet chosen.

• Back in classroom August 2006.

• www.zianet.com/globalcogo/status.html .