2005 MARKHURD Digital Orthophotos, Twin Cities Metropolitan Area

This page last updated: 02/24/2006
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 Metropolitan Council and MARKHURD
Title 2005 MARKHURD Digital Orthophotos, Twin Cities Metropolitan Area
Abstract This licensed dataset from MARKHURD contains 267 black and white, color, and color near-infrared (CIR) orthophoto quarter-quadrangles (DQQs), 3.75' x 3.75' covering the 7-county Minneapolis - St. Paul Twin Cities Metropolitan Area in Minnesota. A quarter-quadrangle is included if its coverage includes any portion of the Twin Cities 7-county area. The orthophotos are in UTM, Zone 15, NAD83 projection with a resolution of 0.6 meter (2 ft pixel). The DOQs were delivered in TIFF and MrSID formats with associated world files. MrSID files are available to MetroGIS participants, upon completion of a license agreement. All others must contact MARKHURD for copies. MrSID black and white DOQs are 11 MB each for a total of 3 GB on 1-DVD. Color and CIR DOQs are 17 MB each for a total of 4.5 GB on 2-DVDs for each, color and CIR. These orthophotos were produced using the USGS DOQ specifications as a guideline. The original imagery was collected at approximately 20,000 ft. using a Zeiss Digital Mapping Camera (DMC).

Samples of the photos can be found at these links:
Black and white: www.datafinder.org/metadata/bg/orthos2005_markhurd_sample_mrsid_bw.jpg
Color: www.datafinder.org/metadata/bg/orthos2005_markhurd_sample_mrsid_color.jpg
CIR: www.datafinder.org/metadata/bg/orthos2005_markhurd_sample_mrsid_cir.jpg
Purpose The digital orthophotos will be used for developing the Metropolitan Council's 2005 Generalized Land Use dataset as will as for many other mapping and analysis functions.

A note about zooming: Generally photogrammetrists suggest that the integrity of a traditional film photo image degrades noticeably after 5 times the negative scale, and that 10 times the negative scale is the absolute maximum one should enlarge a photo. For this dataset, zooming beyond a 1:4,000 scale is not recommended. This applies to the original uncompressed TIFF format orthophoto images. The results for compressed images are more severe.
Time Period of Content Date 04/2005
Currentness Reference The dates of the original aerial photography were April 8, 13 and 14, 2005.
Progress Complete
Maintenance and Update Frequency Unknown
Spatial Extent of Data Twin Cities 7 County Metropolitan Area. This includes the counties of Anoka, Carver, Dakota, Hennepin, Ramsey, Scott and Washington in Minnesota.
Bounding Coordinates -94.06
-92.69
45.44
44.44
Place Keywords Twin Cities, Anoka County, Carver County, Dakota County, Hennepin County, Ramsey County, Scott County, Washingtion County.
Theme Keywords orthophotography, ortho, orthophotos, DOQ, DOQQ, imagery, images, digital ortho, aerial photography, aerial photos, digital aerial photography
Theme Keyword Thesaurus
Access Constraints Subject to License Agreement with the Metropolitan Council and Markhurd.
Use Constraints Subject to License Agreement with the Metropolitan Council and Markhurd.
Copyright and credit to Markhurd is required on all products that include the 2005 Digital Orthophotos.
Licensed MetroGIS participants may not distribute or place the orthophotos on the internet.
Contact MARKHURD for requests, questions or concerns.
Contact Person Information Tanya Mayer, GIS Coordinator
Metropolitan Council, GIS
390 Robert Street North
St. Paul, MN  55101
Phone: 651-602-1604
Email: tanya.mayer@metc.state.mn.us
Browse Graphic Click to view a data sample
Associated Data Sets 2000 Metropolitan Council Digital Orthophotos
1997 Metropolitan Council Digital Orthophotos
1991 USGS DOQs

Section 2 Data Quality
Attribute Accuracy
Logical Consistency
Completeness The Twin Cities Metropolitan Area, which includes the counties of Anoka, Carver, Dakota, Hennepin, Ramsey, Scott and Washington in Minnesota.
Horizontal Positional Accuracy NMAS @ 1:12,000 scale, 90% of well-defined points fall within 33.3 ft
Vertical Positional Accuracy Not applicable
Lineage The 2005 Digital Orthophotos were developed under contract for license with MARKHURD.

MARKHURD acquired new vertical, digital black and white, color, and color infrared, photography at an altitude of 20,000 ft photo scale of 1''= 4,233' (1:50,796) with a 0.6m pixel (2 ft) with Ziess DMC (Digital Mapping Camera) flight lines were N-S with a 60% forward overlap and a 30% side Lap. There were 22 flight lines, 1,132 exposures and exposures were centered at the quarter quad edges, quarter quad center, and one in between with a 12um (0.6 meter) pixel.

The DMC camera consists of 8 sensors: 4 panchromatic sensors and 4 multi-spectral sensors. The multi-spectral sensors are 3K x 2K in size, with one sensor capturing red data, one capturing blue data, one capturing green data, and one capturing near-infrared data (band pass 740-850nm). The four panchromatic sensors each capture one image of a particular area (7K x 4K), which slightly overlap one to another and are used to produce one large mosaic image, 7680 x 13824 in size.

A Fully Analytical Aerotriangulation (AT) of the aerial images was developed to be used in the orthorectification process. The original photo targets were recaptured along with probed data points from the Metropolitan Council's 2000 digital orthophoto project to complete the AT-solution.

The Council provided the USGS 30 Meter DEM to MARKHURD in UTM, NAD83, horizontal units in meters, vertical units (Z-units) in feet, tiled by USGS quadrangle. The DEM files are used in the orthorectification process.

MARKHURD used a softcopy process to create the final digital orthophotos. Digital Orthophoto Quarter-Quads were developed following the USGS standards for digital orthophotos (DOQs) with the exception of pixel resolution 0.6 meters (2 ft) and file format (TIFF with world files). USGS header (.hdr) file were not included as a deliverable.

Each black and white image is approximately 115 Mb with a 0.6 meter image pixel (2 ft).
Each black and white MrSID image is compressed at a 10:1 ratio and is approximately 11 MB.

Each color and CIR image is approximately 350 Mb with a 0.6 meter image pixel (2').
Each color and CIR MrSID image is compressed at a 20:1 ratio and is approximately 17 MB.

For LICENSED MetroGIS Participants
All the black and white MrSID files are available on 1 DVD (3 GB).
All the color MrSID files are available on 2 DVDs (5 GB).
All the CIR MrSID files are available on 2 DVDs (5 GB).

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

Section 4 Coordinate System
Horizontal Coordinate Scheme UTM
UTM Zone Number 15
Horizontal Datum NAD83
Horizontal Units Meters
Cell Width .6
Cell Height .6

Section 5 Attributes
Overview
Detailed Citation
Table Detail:

Section 6 Distribution
Publisher MARKHURD
Publication Date 11/2005
Contact Person Information Tanya Mayer,
Metropolitan Council, GIS
390 Robert Street North
St. Paul, MN  55101
Phone: 651-602-1604
Email: maps@metc.state.mn.us
Distributor's Data Set Identifier 2005 Digital Orthophotos, Twin Cities Metropolitan Area
Ordering Instructions MetroGIS Participants
Go to gis.metc.state.mn.us/data.asp or call the Metropolitan Council GIS at 651-602-1604.


All Others
Contact MARKHURD at markhurd.com or 763-420-9606
Distribution Liability See MetroGIS License Agreement and instructions
Online Linkage None available.

Section 7 Metadata Reference
Metadata Date 02/24/2006
Contact Person Information Tanya Mayer, GIS Coordinator
Metropolitan Council, GIS
390 Robert Street North
St. Paul, MN  55101
Phone: 651-602-1604
Email: tanya.mayer@metc.state.mn.us
Metadata Standard Name Minnesota Geographic Metadata Guidelines
Metadata Standard Version 1.2
Metadata Standard Online Linkage http://www.gis.state.mn.us/stds/metadata.htm


This page last updated: 02/24/2006
Go back to top