This readme file presents the contents of the "Rectification Parameters" folder. The files in this folder contain information pertaining to parameters used in the rectification process, as well as the resulting accuracy of the rectification for the ortho-rectified and the geo-rectified individual aerial photographs*. =========================================================================================================== Listed below are the extensions to photo file names. Each file type contains some unique information not found in the other files. ------------------------------------------------------------------------------------------------------------ _Ortho-Parameters.ort These files contain the complete registration parameters for both the ground control coordinates and the photo film information (e.g., fiducial mark coordinates and focal length) for the ortho-rectification process in ENVI software. They include the relation between ground control ("exterior") and fiducial ("interior") coordinates and their corresponding locations in Cartesian photo (pixel) coordinates. Not included in these files are RMS errors for individual registration control points. ............................................................................................................ _Reg-Table.txt These files contain parameters and accuracy results for ground control ("external") registration for the ortho-rectification process in ENVI software. The files exclude information pertaining to the film registration, but present a complete picture of the ground control registration, including the UTM coordinates of the aerial crosses (ground control points), the corresponding locations of those crosses in photo units (pixels), and the accuracy of the registration between the former and the latter. Also included is the total RMS error for all points used in the registration and rectification for a given photo. ............................................................................................................ _Fiducial-XY.txt These files contain parameters and accuracy results for photo film coordinate registration for the ortho-rectification process in ENVI software. The files exclude information pertaining to ground control registration, but present a complete picture of the film coordinate registration, including the location of the fiducial mark coordinates in millimeters, the corresponding locations of those fiducial marks in photo units (pixels), and the accuracy of the registration between the former and the latter. Also included is the total RMS error for all fiducial marks (all 8 were used) included in the registration and rectification for a given photo. ............................................................................................................ _ref_gcp.gcc These files present essentially the same information as the _Ortho-Parameters.ort files (see above), except the format is native Erdas Imagine rather than simple text format. The Brown's Island photos were ortho-rectified using Imagine instead of ENVI, and thus these files only exist for that site. ............................................................................................................ _fiducial-xy.gms These files present essentially the same information as the _Fiducial-XY files (see above), except the format is native Erdas Imagine rather than simple text format. The Brown's Island photos were ortho-rectified using Imagine instead of ENVI, and thus these files only exist for that site. ............................................................................................................ .dbf .shp .shx These are ESRI ArcView GIS shapefiles, and represent the point locations for ground control points used to geo-rectify the not-selected site photographs. RMS accuracy information for individual points, as well as the collective total, is included in the .dbf file wherever at least four points were used in the registra- tion/rectification process. The files are an optional by-product, created upon completion of the registration process in ArcView's Image Analyst. *Individual rectified photos have not been included for those sites which ultimately were not selected for the IRWM Pilot Project. However, the rectification shapefiles have been included to provide some basic information pertaining to the accuracy of the individual geo-rectified photos included in the site mosaic image files. =========================================================================================================== For additional information, contact Wetlands and Water Resources: 1010 B St, Suite 425 San Rafael, CA 94901 (415) 457-0250 | www.swampthing.org This document was created by Jake Schweitzer, February 2004