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Washington County, MN - Orthoimages
This page last updated: 04/18/2017
none available
Metadata Summary
Originator | Survey Division - Washington County Public Works |
Abstract | This task order consists of digital orthophoto production covering the Washington County, Minnesota area. The data set consists of 0.5-foot pixel resolution three band orthoimages. The data is projected in NAD 1983 Washington County Coordinate System 1986 - US Survey Feet |
Browse Graphic | none available |
Time Period of Content Date | |
Currentness Reference | ground condition |
Access Constraints | None |
Use Constraints | None. However, users should be aware that temporal changes may have occurred since this data set was collected and that some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations. |
Distributor Organization | |
Ordering Instructions | |
Online Linkage | none available |
Full Metadata
Washington County, MN - Orthoimages
Go to Section:
1. Identification Information
2. Data Quality Information
3. Spatial Data Organization Information
4. Spatial Reference Information
5. Entity and Attribute Information
6. Distribution Information
7. Metadata Reference Information
Section 1 | Identification Information | Top of page | ||
Originator | Survey Division - Washington County Public Works | |||
Title | Washington County, MN - Orthoimages | |||
Abstract | This task order consists of digital orthophoto production covering the Washington County, Minnesota area. The data set consists of 0.5-foot pixel resolution three band orthoimages. The data is projected in NAD 1983 Washington County Coordinate System 1986 - US Survey Feet | |||
Purpose | This data depicts geographic features on the surface of the earth. | |||
Time Period of Content Date | ||||
Currentness Reference | ground condition | |||
Progress | Complete | |||
Maintenance and Update Frequency | irregular | |||
Spatial Extent of Data | Dates of Acquisition: Imagery was collected on April 14, 2016, April 15, 2016; April 23, 2016; April 30, 2016; May 2, 2016; May 3, 2016. The imagery for this project was flown at a nominal acquisition altitude (AGL) of 6,800 feet. Differential baseline lengths were kept to a minimum by the use of the nearest available CORS stations to the project area. GPS coordinates were referenced to the National Spatial Reference System (NSRS) through connections to active CORS and/or passive monumented control stations. The digital camera was calibrated by the manufacturer and the camera parameters refined through in-situ proprietary procedures. | |||
Bounding Coordinates | -93.0463817980985 -92.7184328285402 45.2984718935024 44.7299076459292 |
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Place Keywords | US | |||
Theme Keywords | 0.5 foot orthoimage | |||
Theme Keyword Thesaurus | None | |||
Access Constraints | None | |||
Use Constraints | None. However, users should be aware that temporal changes may have occurred since this data set was collected and that some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations. | |||
Contact Person Information | John Baer, Survey Project Coordinator Survey Division - Washington County Public Works 11660 Myeron Road North Stillwater, MN 55082 Phone: 651-430-6883 FAX: E-mail: john.baer@co.washington.mn.us | |||
Browse Graphic | none available | |||
Browse Graphic File Description | ||||
Associated Data Sets | |
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Section 2 | Data Quality Information | Top of full metadata | Top of page | |
Attribute Accuracy | Radiometry is verified by visual inspection of the digital orthophoto. Slight systematic radiometric differences may exist between adjacent orthoimage files; these are due primarily to differences in source image capture dates and sun angles along flight lines. These differences can be observed in an image's general lightness or darkness when it is compared to adjacent orthoimage file coverages. Tonal balancing may be performed over a group of images during the mosaicking process which may serve to lighten or darken adjacent images for better color tone matching. | |||
Logical Consistency | Orthophotos conform to the specifications set forth by Washington County for this contract. Data cover the entire area specified for this project. All GeoTIFF tagged data and image file sizes are validated using commercial GIS software to ensure proper loading before being archived. This validation procedure ensures correct physical format and field values for tagged elements. Seamlines and tile edges are visually inspected. Seamline mismatches are not corrected unless the overall displacement exceeds one meter. | |||
Completeness | Orthoimages are visually inspected for completeness to ensure that no gaps or image misplacements exist within and between adjacent images. These images are derived by mosaicking multiple images to ensure complete coverage. Source imagery is cloud free. | |||
Horizontal Positional Accuracy | The horizontal accuracy of the orthorectified images is mainly determined by the quality of the DEM. The elevation data was existing LiDAR data provided by the state of Minnesota website. Airborne GPS/IMU data was used. All photo identifiable checkpoints were measured and compared to the surveyed checkpoints to determine the RMSE. All rectified chip overlap was checked for mismatch. Final imagery was cut into client supplied tiles for delivery. | |||
Lineage | Digital aerial imagery was obtained using a large format Leica ADS 100 camera equipped with Airborne GPS/IMU covering the AOI. The imagery was collected during leaf off conditions in the spring of 2016 under conditions free from clouds and cloud shadows, smoke, fog, haze, light streaks, snow, ice on water bodies, foliage, flooding, and excessive soil moisture. The sun angle threshold was 30 degrees. The imagery consisted of panchromatic, blue, green, red and near infrared bands. The three color bands and near infrared bands have been pan sharpened and archived as frame imagery. | |||
Source Scale Denominator | ||||
Section 3 | Spatial Data Organization Information | Top of full metadata | Top of page | |
Native Data Set Environment | Leica MissionPro; PhotoShop; MicroStation; ArcGIS 10.3; MicroStation Version 8; TerraScan; TerraModeler; GeoCue; Esri ArcGIS; Global Mapper 16; Leica Cloud Pro 1.2; Windows 10 Operating System | |||
Geographic Reference for Tabular Data | ||||
Spatial Object Type | ||||
Vendor Specific Object Types | ||||
Tiling Scheme | ||||
Section 4 | Spatial Reference Information | Top of full metadata | Top of page | |
Horizontal Coordinate Scheme | ||||
Ellipsoid | GRS 1980 | |||
Horizontal Datum | ||||
Horizontal Units | Foot_US | |||
Distance Resolution | ||||
Cell Width | 0.5 | |||
Cell Height | 0.5 | |||
Map Projection Name | NAD 1983 Washington County Coordinate System 1986 - US Survey Feet | |||
Section 5 | Entity and Attribute Information | Top of full metadata | Top of page | |
Entity and Attribute Overview | Natural color orthoimagery is organized in three color bands or channels which represent the red, green, and blue portions of the spectrum. Each image pixel is assigned a triplet of numeric values, one for each color band. Numeric values range from 0 to 255. There are no void areas. | |||
Entity and Attribute Detailed Citation | U.S. Department of the Interior, U.S. Geological Survey, 1996, Standards for Digital Orthophotos: Reston, VA. | |||
Section 6 | Distribution Information | Top of full metadata | Top of page | |
Publisher | Washington County, Minnesota | |||
Publication Date | 2016 | |||
Contact Person Information | , Phone: FAX: E-mail: none available |
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Distributor's Data Set Identifier | ||||
Distribution Liability | ||||
Transfer Format Name | ||||
Transfer Format Version Number | ||||
Transfer Size | ||||
Ordering Instructions | ||||
Online Linkage | none available | |||
Section 7 | Metadata Reference Information | Top of full metadata | Top of page | |
Metadata Date | 07/27/2016 | |||
Contact Person Information | John Baer, Survey Project Coordinator Survey Division - Washington County Public Works 11660 Myeron Road North Stillwater, MN 55082 Phone: 651-430-6883 FAX: E-mail: john.baer@co.washington.mn.us |
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Metadata Standard Name | ||||
Metadata Standard Version | FGDC-STD-001-1998 | |||
Metadata Standard Online Linkage |
This page last updated: 04/18/2017