Mission Planning for aGPS Control Survey Using ESRI ArcMap

August 8, 2004Mickie Warwick, PLS

Using ArcMap for GPS Mission Planning

• Surveyors are not tapping into the benefits that can be derived from using GIS

• Many presentations aimed at ‘bridging the gap’ show how survey data can be used to improve the accuracy of a GIS project

• This presentation will show how GIS was used to expedite a GPS Cadastral survey.

The Project

• GLO notes for Pre-European Settlement ecological conditions – Don Bragg, Forest Reseacher USDA Forest Service

• Geographic Coordinate Data Base (GCDB)

• Standards for the National Map and FGDC• GCDB• Standards for GPS Surveys

The Project

Standards and Guidelines for Cadastral Surveys Using Global

Positioning System Methods

May 9, 2001

United States Department of Agriculture – Forest ServiceUnited States Department of Interior – Bureau of Land Management

Local Accuracy Standards

II. Cadastral Measurements

Less than 0.100m

I. Cadastral Project Control

Less than 0.050m

Application95% Confidence Circle

Local accuracy is a measure of the relative accuracies of the coordinates for a point with respect to adjacent points at the 95% confidence level.

Network Accuracy Standards

II. CadastralMeasurements

Less than 0.200m

I. Cadastral Project Control

Less than 0.100m

Application95% Confidence Circle

The network accuracy shows the relationship of the cadastral survey relative to the National Spatial Reference System.

Standards and Guidelines for Cadastral Surveys Using Global Positioning System Methods

• Standards developed to provide guidance to Cadastral Surveyors in the use of carrier phase GPS technology to perform Public Land Survey System (PLSS) surveys on public lands

• Representatives of the U.S.D.A. Forest Service and the Bureau of Land Management jointly developed these standards and guidelines. They include other federal agencies, including the National Geodetic Survey, existing GPS control survey standards and guidelines, and opinions and reviews from other public and private land surveyors who use GPS for cadastral (boundary) surveys.

• Cadastral surveys are a critical part of the National Spatial Data Infrastructure. These standards and guidelines are in accordance with the accuracy reporting requirements of the Federal Geographic Data Committee's "Geospatial Positioning Accuracy Standards," July, 1997.

Gathering Basic Resources

From the Spatial Analysis Lab at the University of Arkansas at Monticello

• USGS 7.5 minute quadrangle maps

• Color Infrared aerial photography

I. Cadastral Project Control

• Horizontal and Vertical Control Datasheets from the National Geodetic Survey

• Paper copies of the datasheets for use in the field

• Downloaded points in GIS format for the map and to import coordinates into Resource Grade GPS for Reconnaissance

Checking for overhead cover

Fieldwork

• Requirement for at least two High Accuracy Reference Network (HARN) points - easy to find because the horizontal coordinates are really good

• Requirement for at least one vertical control monument in each quadrant of the job –preferably just outside and surrounding the project area – to help define the geoid

Planning the GPS Sessions• Every point must be occupied at least twice with a

percentage being observed three times – redundancy (Cadastral Standards)

• Using existing or newly set monuments, the sessions are planned using GIS

• Computations are made to determine the number of sessions that will be necessary (Van Sickle – GPS for Surveyors)

• The baseline vectors can be measured on the map to determine the approximate time of occupation on each point (Wolf & Ghilani – Elementary Surveying textbook)

• Routes for each observer are determined and a schedule is made

4:45 PM3:00 PM12:30 PM10:45 AM9:00AMSTOP TIME

3:45 PM2:00 PM11:30 AM9:45 AM8:00 AMSTART TIME

1V9H5H4H7H5. Mickie Warwick

9H4H4V5H5H4. James Barnett

6V6V8H4V2H3. Jason Beck

8H5V6H6H3V2 Kevin Hicks

1H7H5V3V3H1. Bill Gagner

SESSION 5SESSION 4SESSION 3SESSION 2SESSION 1OBSERVER

SATURDAY MARCH 6, 2004 ASHLEY COUNTY

II. Cadastral Measurements

• Data from corner cards at the State Surveyors Office

• Survey Plats from State Surveyors Office and County Courthouse

• Records at Potlatch Timber Company in Warren• Records at Plum Creek Timber Company in

Crossett• Map from Arkansas Game and Fish – Felsenthal

Wildlife Management Area

Nov. 26, 1986394April. 28,1842A. Bowman17S08W600600E-2128W17S

May. 20, 1982394May. 6, 1842A. Bowman17S08W200440L-5188W17S

April. 30, 1982394May. 7, 1842A. Bowman17S08W240600E-758W17S

June. 12, 1985394Dec. 24, 1827N. Rightor17S08W700640C-2518W17S

July. 9, 1987394Jan. 8, 1828N. Rightor17S07W540100Z-19357W17S

May. 10, 1982394Mar. 1, 1841A. Bowman17S07W500200V-17347W17S

April. 30, 1982394Mar. 1, 1841A. Bowman17S07W500240T-17277W17S

July. 9, 1987394Feb. 27, 1841A. Bowman17S07W700300R-25257W17S

May. 10, 1982394Mar. 1, 1841A. Bowman17S07W500300R-17227W17S

May. 10, 1982394Feb. 28, 1841A. Bowman17S07W600600E-2127W17S

Mar. 9, 1984394Jan. 13, 1841A. Bowman17S06W340300R-11216W17S

July. 9, 1987394Jan. 15, 1841A. Bowman17S06W100300R-1 196W17S

July. 9, 1987394Jan. 15, 1841A. Bowman17S06W140300R-3196W17S

Mar. 9, 1984394Jan. 10, 1841A. Bowman17S06W500500J-17106W17S

Sept. 20, 1984394Jan. 27, 1841A. Bowman17S06W200540G-576W17S

May. 10, 1982394Jan. 14, 1841A. Bowman17S06W300600E-946W17S

Mar. 9, 1984394Jan.11, 1841A. Bowman17S06W500600E-1736W17S

Sept. 15, 1990394Jan. 3, 1840John Clark17S05W600200V-21265W17S

Nov. 6, 1986394Jan. 4,1840Andrew B Clark17S05W500300R-17265W17S

Jan. 30, 1991394Jan. 23, 1840John Clark17S05W400540G-1395W17S

Mar. 10, 1984394Jan. 26, 1840John Clark17S05W300500J-985W17S

Mar. 10, 1984394Jan. 28, 1840John Clark17S05W200700A-565W17S

Date_SetPLS_No.Date_Org.Org._SurveyorGCDB_CodeIndexSectionRangeTnwp

The use of GIS significantly reduced the time it took to plan and execute a GPS

survey to meet the Cadastral Standards for

GPS and there was “benefit added”.

Conclusion