Digital Orthoimagery, McLeod County, Minnesota, Spring 2014

This page last updated: 11/13/2015
Metadata created using Minnesota Geographic Metadata Guidelines

Go to Section:
1. Overview
2. Data Quality
3. Data Organization
4. Coordinate System
5. Attributes
6. Distribution - Get Data
7. Metadata Reference

Section 1 Overview
Originator McLeod County; Quantum Spatial, Inc.
Title Digital Orthoimagery, McLeod County, Minnesota, Spring 2014
Abstract This dataset contains leaf-off 4-band red, green, blue, natural color and color infrared (CIR) digital orthophoto imagery produced at 6-inch resolution from new aerial photography captured in Spring 2014. The imagery covers McLeod County in central Minnesota. This metadata record was created by MnGeo using information supplied by Quantum Spatial, Inc.
Purpose To support multi-agency efforts including transportation planning, wetland mapping, urban planning, forest management, soil mapping, and utility management.
Time Period of Content Date 05/2014
Currentness Reference Ground condition. Imagery was flown April 25 - May 17, 2014
Progress Complete
Maintenance and Update Frequency None Planned
Spatial Extent of Data McLeod County, Minnesota
Bounding Coordinates -94.50
Place Keywords Minnesota, MN, McLeod
Theme Keywords imageryBaseMapsEarthCover, Orthophotography, Digital Orthophotography, Ortho, Orthophotos, Digital Orthorectified Images, Digital Orthophotos, DOQ, DOQQ, Imagery, Images, Aerial Photography, Aerial Photos, Digital Aerial Photography, Air Photo, Color Infrared, Four Band Imagery
Theme Keyword Thesaurus ISO 19115 Topic Category
Access Constraints Unrestricted
Use Constraints MnGeo Redistribution conditions: In obtaining this data from the Minnesota Geospatial Information Office (MnGeo), it is understood that you and/or your organization have the right to use it for any purpose. If you modify it, you are encouraged to apply responsible best practices by documenting those changes in a metadata record. If you transmit or provide the data to another user, it is your responsibility to provide appropriate content, limitation, warranty and liability information as you see fit.
Contact Person Information Christy Christensen, GIS Director
McLeod County
1400 Adams Street SE
Hutchinson, MN  55350
Phone: 320-234-0230
Browse Graphic None available
Associated Data Sets For information on other air photos available for Minnesota, see:

Section 2 Data Quality
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 None
Completeness All planned 2014 acquisition was completed. Orthoimages are visually inspected for completeness to ensure that no gaps or image misplacements exist within project limits and between adjacent images. These images are derived by mosaicking multiple images to ensure complete coverage. Source imagery is cloud free.

This data has an anomaly when displayed on MnGeo's Web Map Service. The data was prepared by the vendor as specified by the county in non-overlapping tiles in McLeod county coordinates. When the tiles are converted to UTM Zone 15, they do not overlap perfectly in the WMS due to rounding errors. This causes a white (offsite) dashed line, about 1/3 on and 2/3 off, to appear between the tiles in the finished product. The line is one-pixel wide, and thus only visible at the highest resolutions, scale factors of about 1:2000 or closer. When viewed at a resolution of one image pixel per display pixel (about 1:500 or so), about 10% of the scenes will contain the line.
Horizontal Positional Accuracy 0.76 feet CE 90. Horizontal accuracy was stated to meet or exceed 1.74 survey feet, CE90 or the 95% equilivant of 3.03 feet per NSSDA (National Standard for Spatial Data Accuracy). Airborne GPS data was collected during acquisition and ground control points surveyed. Targeted positions were supplied to the county to verify ortho accuracy.
Vertical Positional Accuracy None - this is a horizontal only product.
Lineage Sources:
1. Minnesota 10-foot DEM, used to provide ground elevations for orthorectification process.
2. MN 0.5-foot Area Aerotriangulation, Quantum Spatial, Inc., December 2014: Used to provide photo exterior orientations for orthorectification process.

Processing Steps:

The acquisition was done using multiple Intergraph DMCs (Digital Mapping Cameras) during 2014 Spring leaf-off conditions allowing for 5% snow and cloud cover. Digital camera(s) were calibrated by the manufacturer and the camera parameters refined through in-situ proprietary procedures. The flying height was 4850 feet AMT (above mean terrain) and imagery data was captured in 12-bit for four bands (Red-Green-Blue-Near Infrared). The data was then processed using Intergraph's PPS software into 12-bit, 4-band images which were then adjusted using Intergraph's DIA (DMC Image Analyst) software.

Airborne GPS and IMU data was processed and used in beginning the aerial triangulation (AT) processing which was done using INPHO's Match-AT software. The resulting exterior orientations for each frame were used along with the DMC images and a 10-foot gridded DEM generated from the downloaded statewide LiDAR datasets to do a rectification using INPHO's OrthoMaster software.

The orthorectified frames were then further adjusted using INPHO's OrthoVista - Radiometrix Editor and seamlines automatically generated. Those seamlines were completely reviewed and edited to ensure no man-made features were clipped as well as to optimize seamline locations in general. Once the seamlines were edited the images were mosaicked and big tiles were cut for review and editing purposes.

The big tiles were completely reviewed and calls made for warped bridges and other artifacts which were then corrected. Then a QC was performed on 10-15% of the tiles focusing on urban areas and other important features. Once all QC edits were complete the big tiles were then used to cut out the final tiles. Finally, the near-infrared band was adjusted per the client's direction and the images were formatted for final delivery.

Software versions: IRAS C ver 10.0, Photoshop ver CS5, Windows XP and Windows 7, INPHO OrthoVista 5.5, Global Mapper 13, Bentley MicroStation 7 and 8, INPHO Match-AT 5.5, INPHO OrthoMaster 5.5

The data was distributed to MnGeo in non-overlapping tiles in McLeod county coordinates. MnGeo converted the imagery to UTM Zone 15 coordinates and created a WMS service.

Section 3 Spatial Data Organization (not used in this metadata)

Section 4 Coordinate System
Horizontal Coordinate Scheme Universal Transverse Mercator
UTM Zone Number 15
Horizontal Datum NAD83
Horizontal Units meters
Cell Width .15
Cell Height .15

Section 5 Attributes
Overview Imagery has 4 Bands with the order of Red, Green, Blue and Near Infrared
Detailed Citation
Table Detail:

Section 6 Distribution
Publisher Minnesota Geospatial Information Office (MnGeo)
Publication Date 2015
Contact Person Information Nancy Rader, GIS Data Coordinator
Minnesota Geospatial Information Office (MnGeo)
658 Cedar Street, Room 300
St. Paul, MN  55155
Phone: 651-201-2489
Fax: 651-296-6398
Distributor's Data Set Identifier McLeod County Imagery 2014 (base_mcleod_2014_airphotos)
Distribution Liability MnGeo's full disclaimer is here:
Ordering Instructions The imagery is available to view as a WMS via MnGeo's Geospatial Image Service. The Geospatial Image Service web pages provide information for connecting to the server as well as information on how to use WMS Services. Due to file size there is currently no option to download the photos.
Online Linkage I AGREE to the notice in "Distribution Liability" above. Clicking to agree will either begin the download process, link to a service, or provide more instructions. See "Ordering Instructions" above for details.

Section 7 Metadata Reference
Metadata Date 11/13/2015
Contact Person Information Nancy Rader, GIS Data Coordinator
Minnesota Geospatial Information Office (MnGeo)
658 Cedar Street, Room 300
St. Paul, MN  55155
Phone: 651-201-2489
Fax: 651-296-6398
Metadata Standard Name Minnesota Geographic Metadata Guidelines
Metadata Standard Version 1.2
Metadata Standard Online Linkage

This page last updated: 11/13/2015
Go back to top