Charles Kiblinger - River History Project - University of Washington
Publication_Date: September, 2003
Title: Snohomish River orthophotos - 1938
Geospatial_Data_Presentation_Form: raster digital data
Description:
Abstract:
This dataset is part of a large collection of historical aerial photographs that were orthorectified. The photos were recieved in digital format from Suzy Brunzell, Surface Water Management, Snohomish County Public Works, 2731 Wetmore Ave, Suite 300, Everett WA 98201-3581, 425.388.3464 X4533, fax 425.388.6455, suzy.brunzell@co.snohomish.wa.us. This image dataset was created from 53 individual photos (stored in TIFF format) which were orthorectified, mosaicked, and tiled into rectangular sections approximately 4900+ meters by 7000+ meters. (Sections are roughly the extents of slightly overlapping USGS Digital Ortho Quarter-quads found at <https://duff.ess.washington.edu/data/raster/doqs/>). Data does not necessarily fill each section completely.
Scale: approx. 1:10,000
Supplemental_Information:
Black and white photographs were scanned at 400 pixels per inch, grayscale, and saved as TIFF files. Performed "Auto Levels" in Photoshop and used Photoshop to change all pixels of value 0,0,0 to 1,1,1 (to avoid dropout of 0,0,0 pixels when turning off display of background value 0 in ArcMap). Resulting TIFF images were then orthorectified using ERDAS Imagine's OrthoBASE module. Registration sources were USGS Digital Ortho Quarter-quads (<https://duff.ess.washington.edu/data/raster/doqs/>) and a USGS 10-meter DEM (<https://duff.ess.washington.edu/data/raster/tenmeter/byquad/>).
Brian Collins, Amir Sheikh, Harvey Greenberg, Charles Kiblinger, University of Washington, Seattle, WA
Security_Information:
Security_Classification: Unclassified
Native_Data_Set_Environment:
Microsoft Windows 2000 Version 5.1 (Build 2600) Service Pack 1; ESRI ArcCatalog 8.3.0.800
Data_Quality_Information:
Attribute_Accuracy:
Quantitative_Attribute_Accuracy_Assessment:
Completeness_Report:
Images cover the river bottoms and some of the adjacent uplands for the Snohomish River from the delta to approximately the confluence of the Skykomish and Snoqualmie Rivers.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Average residual values for the X, Y, and Z control point coordinates from ERDAS Imagine OrthoBASE Triangulation Report (measured in meters):
aX: -0.1050 aY: -0.9297 aZ: 3.0345
Root mean square errors (standard deviation) of all X, Y, and Z from ERDAS Imagine OrthoBASE Triangulation Report (measured in meters):