# Presentation: 622560

## Improving NGS ProductsNGS Fall Convocation Holiday Inn – Silver Spring, MD.October 24-28, 2005

**Earl F. Burkholder, PS, PE**
**New 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**

## Slide 11

## Slide 12

## Slide 13

## 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).

## Slide 16

## Slide 17

## Slide 18

## Slide 19

## 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](http://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](http://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?

## Slide 27

## 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 BURKORDTM software is coming along.  Will be gratis with book.
- Publisher not yet chosen.
- Back in classroom August 2006.
- _[www.zianet.com/globalcogo/status.html](http://www.zianet.com/globalcogo/status.html)__ ._