# Presentation: 421246

## Questions?  

**Height Modernization and Leveling**
**Focus Group Meeting**
**Thursday, October 7, 2004**
**Juliana Blackwell**
**Height Modernization Program Manager**
**  **
**Frank Mowry**
**Leveling Team Leader**

## Height Modernization is . . .   

- Height Modernization is . . .
- the establishment of accurate, reliable heights using GPS technology in conjunction with traditional leveling, gravity, and modern remote sensing information.

**Notes:**
Height Modernization integrates the latest GPS technology with historic survey data in NGS database (conventional leveling, gravity data).
In the past, NGS had two separate “control” networks – horizontal and vertical.  With GPS, we can measure 3-D accurately.  
The problem is that new GPS heights and “heights above sea level” determined through line-of-sight measurements must first be linked. 
Height Modernization is used to position and tie survey marks together – to 2 cm local vertical accuracy, horizontally to 1-2 cm.

## Height Modernization Objective

## Height Modernization Objective

** **** **

** **

- NSRS

- NAVD 88

- GEODETIC CONTROL

- National Vertical Datum accessed through
-  the NSRS Infrastructure that is:

**Reliable**

**Cost-effective**

**Accurate**

**Standardized**

**Legally Established**

## Background

**Notes:**
History 
California first state to draw attention to deficit in NAVD 88.  Hard to pin down movement in CA.  A lot of the state did not get adjusted in NAVD 88.  Especially southern California because the leveling was so old.  Grassroots effort to begin Height Modernization.

In 1997, Height Modernization was mentioned in our appropriation language for the first time. No money allocated, but NGS encouraged to investigate the concept of height modernization.
In 1998, $1.0 M was added to NGS budget to perform Height Modernization Study.
In 1999,  Height Modernization not mentioned.
In 2000, $500K added to NGS budget to perform Height Modernization planning
In 2001, $2.25 M added to NGS budget to perform Height Modernization in North Carolina, to support the California Spatial Reference Center (CSRC), and to support NGS related Height Modernization activities.
ALSO In June 2001, NGS was directed to report to Congress about the Height Mod needs of Louisiana and Wisconsin.  Louisiana had similar issues with data not being adjusted into NAVD 88.  (Due to subsidence).  Wisconsin had a very active Height Mod program by the DOT.  Very active in GIS.  Problems with obsolete geodetic control and rapid land loss thru subsidence and erosion.

FY 2004:
CA 1.0M
NC 1.0M
LA 0.5M
WI 3.0M
MS 0.5M
AL 2.0M
WA 0.5M
SC 0.5M

## Height Modernization 

- Why Height Modernization?

**Notes:**
Navigation Control: active maritime shipping and navigation through inland waterways.
Transportation Control: highway, rail, and airway monitoring.
High-yield farming: connecting remote sensing and GIS to the application of fertilizers and pesticides onto farmland. 
Construction: Machine control by GPS.
Emergency Management: locating infrastructure and efficiently moving resources to their destination.
Flood Management: measuring flood zones precisely on a common framework is critical.
Crustal Motion: studies of the earth’s surface and reactions to motion.

## Height Modernization Project

**Notes:**
Sample Monument Spacing:

HARN 			50 km	(75 km max for 2 cm)
Primary GPS		20-25 km	(40 km max for 2 cm)
Secondary GPS		12-15 km	(15 km max for 2 cm)
Local GPS			6-8 km	(10 km max for 2 cm)

In addition to the HARN and primary control, ALL secondary and local base stations will have GPS-derived “orthometric” heights.

## Height Modernization Status

**Notes:**
NGS’ Height Modernization web page will have map similar to this one (soon) – indicating states have been funded for Height Mod (purple) and states that have demonstrated a strong interest and outreach program for future Height Mod programs in their state (light blue). 

Once the web page is fully constructed, you will be able to click on a state and find out about projects, meetings, forums, who to contact, etc...

FY 2004:
CA 1.0M
NC 1.0M
LA 0.5M
WI 3.0M
MS 0.5M
AL 2.0M
WA 0.5M
SC 0.5M

## EXAMPLE:  Floodplain Maps

- Flood Insurance Risk Maps
- Determining High Water Marks
- Elevation Certificates
- Dam Safety
- Mitigation

**Notes:**
Height Modernization improves the “foundation” for the determination of floodplain maps for FEMA’s Map Modernization program.
Digitizing maps that are based on outdated, inaccurate heights is not worthwhile – ensuring that the heights used for the floodplain and flood insurance rate map are updated and accurate is critical. 
Areas shown in pink delineate the “New 100 yr floodplain” (with HeightMod) – areas in light blue the previous “FEMA Effective Approximate 100yr floodplain” (old survey control)
Builders, owners and planners in “pink” areas now aware that they are in the 100yr floodplain and will be able to insure their property as needed.  Future building and zoning will done with better knowledge of elevations and flood risks.
Property owners no longer in 100yr floodplain save $ by not needing to purchase flood insurance.

Benefits to FEMA:
Three dimensional geodetic control network to support map modernization
Establish bench marks in remote areas (2 centimeters)
Global Positioning System (GPS) base station network to support collect of elevation (LIDAR and photogrammetry) and imagery
Compared to traditional leveling, GPS heights can be established at a reduced cost
Quickly establish bench marks in declared disaster areas to support recovery and mitigation
Support the development of flood warning systems
Provide elevation data to support dam breach analysis

Potential Products and Tools for Map Modernization
Height Modernization control for floodplain maps and LIDAR surveys
OPUS for floodplain certificates and LIDAR surveys
Subsidence rates, maps, and tools for floodplain managers
Guidelines for use of GPS and LIDAR for floodplain mapping

## EXAMPLE:  Evacuation Routes   

## Wisconsin Height Modernization Plan

**Notes:**
Began in 1998 - Wisconsin Department of Transportation 
Improve height data (i.e., the vertical component of the geodetic network) in Wisconsin  
Goal - to eliminate inconsistencies between horizontal and vertical control data 
Supplement control where marks have been destroyed
Create network that can fully utilize GPS technologies  (cost effective)

Products of HMP:
Conventionally Leveled Bench Marks (BM’s)
	FGCS 2nd Order Class 1
	Published on North American Vertical Datum of 1988 (NAVD 88)
GPS Stations
	Horizontal FGCS B-order and 1st Order and GPS derived Vertical 2-cm positional accuracy
	Published on North American Datum of 1983 (1997 adjustment) (NAD 83 (97)) and NAVD 88

Proposed Timeline (April 2004): 
	     Phase 5	Phase 6		Phase 7		Phase 8
2004	   Level/GPS	 	Monument		Recon			---
2005	   Adjust/Publish	Level/GPS		Monument		Recon
2006	    ---			Adjust/Publish	Level/GPS	    	Monument
2007	     ---			---			Adjust/Publish      Level/GPS 
2008	     ---			---			---		         Adjust/Publish

Winnebago County updated 10’ contour maps to 2’ contour maps
2,400 structures removed from the floodplain – save on unnecessary flood insurance, property values increase
1,300 structures added to the floodplain – can purchase protection

Total savings to these owners $14 million!

## LEVEL I NG

- Datasheet

- Existing
- .DSC

- New .DSC Entry

- WinDesc

- Whalen or Archer-Shee Field Software

- .HGF
- (Field Book)

- Valid
- .DSC

- NGS IDB

- WinNewrec

- .HGZ
- Bluebook

- WinAbstra

- .RPT
- File

- Load_desc

- R6out
- (reduce 6)

- Linetool web application
- (Brian Shaw)
- flowchart

- R6adj
- Adjusted data

- Field
- R6adj data

- Internet
- access

- .ABS
- (Field Abstract)

- Web
- Discrep
- Web Neighbor

- .HGZ ASCII and
- Binary

- Internal instrument data collection

- Verrec

- FLOWCHART

## NGS’ Role and Responsibilities

**Outreach/Technology Transfer -- **advisors, forums, workshops, conferences, publications, training, outsourcing
**Project Leadership** -- project planning, specifications, guidelines, CORS management
**Quality Control** -- training, assess techniques, survey control, load projects into NGS database
**Research and Development** – software development, remote sensing, modeling, investigate GPS techniques, antenna calibrations

## Partnerships

**	****State Agencies –****	**North Carolina Geodetic Survey
- 			South Carolina Geodetic Survey
- 			Wisconsin Department of Transportation
- 			Alabama Department of Revenue
- 			Washington Department of Natural Resources
**Universities –**  University of Southern Mississippi
- 		North Carolina A&T State University
- 		Louisiana State University
- 		University of California/Scripps
**	****Harris-Galveston Subsidence District**

## Education/Training

- ACSM/FEMA – Certification of Surveyors
- Training Center - Corbin, VA
- GPS/GIS High School Program
- Forums and Workshops
- Development of Information/Materials
- Articles
- K-12 Programs – Is Louisiana Sinking?

## Height Modernization/Leveling...where do we go from here?

**2004**

**1994**

- ROD 1

- INSTR

**2010**