CHaMP Transformation Tool

Read Me

Produced by Chris Garrard & Joe Wheaton

Copyright © 2011 Wheaton

Updated: May, 2011

GNU Licnese

Developer can be contacted through the GitHub repo. The source code is licensed under a GNU Public License as open source and can be downloaded by developers wishing to extend the tool here (requires Visual Studio, C#).

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see http://www.gnu.org/licenses/gpl-2.0.txt (GLP v2 license).

What does it do?

The Ecogemorphology & Topographic Analysis Lab (ET-AL) and the RSGIS Center developed this ArcGIS Add-in for the transformation and projection of CHAMP field survey data into UTM coordinate system given GPS coordinates from three benchmarks. The tool will work with any unprojected data in a file geodatabase, and gives you multiple ways to do a simple transformation based on a shift and rotate. Although other transformation tools exist in ArcGIS, there is not a simple sequence of geoprocessing tools, which allow you to transform vector data in a manner that preserves the high relative accuracy of a total station survey.

Background

The CHaMP Transformation Tool is designed to work very efficiently with data collected in accordance with theCHaMP survey protocol, but will also work for other assumed surveys. This tool is used by field crews in post-processing their topographic and habitat survey data to give them a rough projected coordinate system for their data. This tool would only be used on the first visit to the site. The tool’s primary functions are to:

● Establish a Quasi-UTM coordinate system transformation from the original assumed total station Cartesian coordinate survey into a UTM projection that is rough, but good enough to support rough overlay with other GIS layers (e.g. contextual aerial imagery and 10 m USGS DEMs)

● Import raw survey data from total station (points, polyline and polygon files) and transform data into this new Quasi-UTM coordinate system and save outputs in file geodatabase

● Assist the user in choosing the ‘best’ transformation input parameters (via a shift, rotate and scale transformation; i.e. an affine transformation) based on all possible combinations of survey benchmarks/bearings, through allowing user to review and choose the best fit out of 9 possible transformations by showing table of residual errors (based on using third unused benchmark as a check) & showing a preview of the overlay in the map data display of ArcGIS.

● Record Transformation Model, and updated Control Points for site reoccupation. Write a summary table report.

Requisites

User Requirements:

  • Some understanding of GIS, and the difference between unprojected data (i.e. an assumed cartesian coordinate system) and projected coordinate systems (e.g. UTM)
  • Familiarity with ArcGIS

System Requirements:

  • ArcGIS 10.X

Input Data Requirements:

You need unprojected survey data, which was surveyed in an assumed Cartesian coordinate system, and three benchmarks spread out over the area of interest. The basic requirements are:

  • The input unprojected survey data are feature classes in a file geodatabase (point, polyline and polygon) will work
  • The three benchmarks you surveyed were surveyed both in the unprojected coordinate system (i.e. with a total station) and were located in real geographic space (e.g. with a hand-held GPS or even crudely identified on a projected aerial photograph)

Installation Procedure

Installing

To install, make sure that ArcGIS is not running and any previous versions of the Add-In are removed. Simply double click on the [CHAMP.esriAddIn](http://etalweb.joewheaton.org/CHAMP_TransformationTool/10_1/CHAMP.esriAddIn) after you download it. See this video for step-by-step instructions:

Uninstalling

If you ever need to uninstall the add-in, simply navigate to Customize -> Add-Ins, and remove it. See also:

Support

No formal support is available with this free software. However, do feel free to contact us if you find bugs or have questions. CHaMP crews should use the CHaMP help forum.

Revision History

The CTT 1.0.0 was modified on 3/4/2012 to address the following (see GitHub repo for current changes):

Minor Bugs:

  • Saving Layers wrong
  • Transformation Preview
  • An occasional error/warning message
  • Tab order
  • Sometimes coordinate system combobox was not filled
  • Made the about dialog a little bigger

Added the following features:

  • Shapefile support (previously only worked with file geodatabases)
  • Projection Support (now works for any user specified projection)
  • Benchmark bearings can now be added fro a file
  • She also added the GNU open source license to the code

Acknowledgements

The CHaMP Transformation Tool was developed by Joe Wheaton and Chris Garrard at Utah State University , with design input from Carol Volk and Kelly Whitehead (South Fork Research, Inc.). Funding for this tool was provided by the Bonneville Power Administration (BPA Proposal # 2011-006-00) and NOAA as part of the CHaMP (Columbia Habitat Monitoring Protocol).

.