Wisconsin Coastal GIS Applications Project

The Status of Digital Orthophotos in Wisconsin's Lake Michigan Coastal Counties


Note: This Report is in draft form. Please do not link to this page. 

Table of Contents

Chapter 1 -- Digital Orthophoto Background Information
Chapter 2 -- Digital Orthophotos for Lake Michigan Coastal Counties
Chapter 3 -- Estimated Completion Costs of Digital Orthophoto Quarter-Quad Production
Chapter 4 -- Digital Orthophotos Specifications

Authors

Doug Tallman and David Hart
University of Wisconsin Sea Grant Institute
and
Land Information and Computer Graphics Facility, University of Wisconsin-Madison

Principal Investigators

Stephen J. Ventura
Bernard J. Niemann, Jr.
Land Information and Computer Graphics Facility, University of Wisconsin-Madison

Allen H. Miller
University of Wisconsin Sea Grant Institute
and
Land Information and Computer Graphics Facility, University of Wisconsin-Madison

This research was conducted as part of an agreement between the University of Wisconsin-Madison and the U.S. Army Corps of Engineers, Detroit District under the supervision of David Barilovich.


Chapter 1. Digital Orthophoto Background Information

Digital orthophotos combine the image characteristics of photographs with the geometric qualities of a map. They are produced from aerial photography by removing the effects of camera tilt and relief displacement to provide a planimetric base with true ground position. This rectification process produces geographically correct digital images which can then be used for direct measurement of distance, areas, angles and positions. Because digital orthophotos display features that may be omitted or generalized on maps they are often used as a background layer in a geographical information system to provide a context for other data layers. Digital orthophotos are further used as interim maps, as field references for Earth Science investigations and as tools that support decision-making processes and spatial analyses.

The National Digital Orthophoto Program is a joint effort by the U.S. Geological Survey, the U.S. Forest Service and the U.S. Department of Agriculture’s Natural Resource Conservation Service (NRCS) and Farm Service Agency (FSA) to ensure public domain availability of digital orthophotos for the nation. There are currently over 50,000 digital orthophotos available for distribution and complete digital orthophoto coverage for the coterminous United States is expected by 2004. The DOQs will be updated on a ten-year cycle for most areas and a five-year cycle for areas that undergo rapid rates of land use change.

The digital orthophoto quarter-quadrangle (DOQQ) is the largest scale format available in the National Digital Orthophoto Program. It has a one meter ground resolution and covers an area of 3.75 minutes of longitude by 3.75 minutes of latitude at a scale of 1:12000. In comparison the digital orthophoto quadrangle has a 2 meter ground resolution and covers an area of 7.5 minutes of longitude by 7.5 minutes of latitude at a scale of 1:24000. The digital orthophoto quarter quadrangles come with 50-300 meters of overedge to facilitate edgematching and mosaicking of images for integration into a common coverage.

(Sources: USGS Global Land Information System Website, Digital Orthophoto Quadrangles page:
( http://edcwww.cr.usgs.gov/Webglis/glisbin/guide.pl/glis/hyper/guide/usgs_doq) and USGS DOQQ metadata document "doqsti.txt".)


Chapter 2. Digital Orthophotos for Lake Michigan Coastal Counties

Large-scale digital orthophoto coverage for Lake Michigan coastal counties exists in two formats: the U.S. Geological Survey's 1:12000 scale DOQQs and the Southeast Wisconsin Regional Planning Commission's (SEWRPC) 1:4800 scale orthophoto coverage. Each SEWRPC orthophoto covers a four square mile area comprised of two section-by-two section squares.   Lake Michigan coastal counties in the USGS DOQQ coverage include Marinette, Oconto, Brown, Door, Kewaunee, Manitowoc, and Sheboygan counties (See Figure 1) . Lake Michigan coastal counties covered by SEWRPC include Ozaukee, Milwaukee, Racine and Kenosha counties.
 

Table 1: Lake Michigan Coastal County Digital Orthophoto Status
 
County Source Complete Orthophoto Coverage Available? Number of Orthophotos Needed for Coastal Coverage? Number of Orthophotos Currently Available in Coastal Coverage? Number of Needed Coastal Coverage Orthophotos We Have Percent Coverage We Have Original Format Compiled
Brown USGS Yes 13 13 13 100% JPEG 1992
Door NRCS(USGS) Yes 66 66 65 98% .bil 1992
Kenosha SEWRPC Yes n/a n/a n/a 0% .tif 1995
Kewaunee - No (in production) 9 4 4 44% JPEG, .bil  
Manitowoc USGS Yes 11 11 11 100% JPEG 1992
Marinette - No 9 4 0 0% n/a  
Milwaukee SEWRPC Yes n/a n/a n/a 0% .tif 1995
Oconto - No 11 2 2 18% JPEG, .bil  
Ozaukee SEWRPC Yes n/a n/a n/a 100% .tif 1995
Racine SEWRPC Yes n/a n/a n/a 0% .tif 1995
Sheboygan NRCS(USGS) Yes 8 8 7 88% .bil 1992
 
Note: The data from NRCS is USGS DOQQ data that has been processed into a different format.

Summary of Coverage by County:

Marinette County

7% of Marinette County DOQQ coverage is available (10 of 142 orthophotos), mostly overlap from surrounding counties along the northwestern border (See Figure 2) . Four orthophotos do exist for the eastern coastal area that we are interested in. There have been discussions with NRCS, Bay-Lake Regional Planning Commission and private contractors to examine the feasibility of completing orthophotos for the county.

Nine orthophotos are needed for coastal coverage along the 1000-meter zone (given below as Quadrangle Name–Quadrangle Quadrant):

Table 2: Marinette County Needed DOQQs
Green Island-SW  Oconto East-NE
Marinette East-NW,SE,SW Peshtigo Harbor-NE,NW
Marinette West-NE,SE  

Those orthophotos that are available as part of the current USGS DOQQ coverage are indicated in bold type. We currently do not have copies of these available DOQQs on hand or on order.

Oconto County

17% of Oconto County DOQQ coverage is available (18 of 108 orthophotos) from overlap with adjacent counties that have complete DOQQ coverage. These stretches of overlap occur along the borders of Forest, Menominee and Brown counties (See Figure 3). There has been a meeting at Bay-Lake Regional Planning Commission to discuss orthophoto creation.

Eleven orthophotos are needed for coastal coverage along the 1000-meter zone, we have two of them (given below as Quadrangle Name–Quadrangle Quadrant):

Table 3: Oconto County Needed DOQQs
Little Tail Point-NW Pensaukee-NE,SE,SW
Little Tail Point-SW Suamico-NE
Oconto East-NE,NW,SW Suamico-SE
Oconto Southeast-NW  

The two orthophotos that are available as part of the current USGS DOQQ coverage are indicated in bold type. These quarter-quadrangles are in our possession as overlapping coverage from the Brown County USGS CD.

Brown County

Brown County DOQQ coverage is complete and available from the USGS (See Figure 4). We have a copy of the complete USGS DOQQ coverage on CD-ROM.

Thirteen orthophotos are needed for coastal coverage along the 1000-meter zone (given below as Quadrangle Name–Quadrangle Quadrant):

Table 4: Brown County Needed DOQQs
Dyckesville-SE,SW Little Tail Point-SW
Green Bay East-NE,NW,SE,SW New Franken-NE,NW
Green Bay West-NE,NW,SE Suamico-SE

Kewaunee County

47% of Kewaunee County DOQQ coverage is available (17 out of 36 orthophotos) due to the adjacent counties all having complete DOQQ coverage (See Figure 5). Kewaunee County DOQQs have been authorized and are currently in production, although according to the USGS Global Land Information System they have not been completed yet.

Nine orthophotos are needed for coastal coverage along the 1000-meter zone (given as Quadrangle Name–Quadrangle Quadrant):
 
Table 5: Kewaunee County Needed DOQQs
Algoma-NE,NW,SW Kewaunee-NE,SE
Dyckesville-SE Namur-SW
Forestville-SE Two Creeks-NE

The four orthophotos indicated in bold type are currently in our possession from overlap with other county datasets.

Door County

Door County DOQQ coverage is complete and available from the USGS (See Figure 6). We currently have almost all of the needed orthophoto coverage, obtained from the NRCS.

Sixty-four orthophotos are needed for coastal coverage along the 1000-meter zone. The 1000-meter coastal zone intersected most of the quarter-quad coverage for the Door County Peninsula, except for the southern portion where the peninsula widens. A "donut hole" of two orthophotos was not touched by the buffered coastal zone. In the interest of completeness the two interior orthophotos were included in the coverage even though they don't intersect the 1000-meter coastal zone. With these two orthophotos the total orthophoto count for Door County was sixty-six photos (given below as Quadrangle Name–Quadrangle Quadrant):
 
Table 6: Door County Needed DOQQs
Algoma Northeast-NW,SW Jacksonport-NE,NW,SE,SW
Baileys Harbor East-NE,NW,SW Little Sturgeon Southwest-NE,SE,SW
Baileys Harbor West-NE,SE Little Sturgeon-NE,NW,SW
Baileys Harbor West-NW Namur-NE,NW,SW
Chambers Island Northwest-NE,SE Sister Bay-NE,NW,SE,SW
Chambers Island-NW,SW,SE Spider Island-NW
Egg Harbor-NE,NW,SE,SW Sturgeon Bay East-NE,NW,SE,SW
Ellison Bay-SE,SW Sturgeon Bay West-NE,NW
Ephraim-NE,SE,SW Washington Island Northeast-SE,SW
Forestville-NE,SE Washington Island Northwest-SE,SW
Idlewild-NE,SE,SW Washington Island Southeast-NE,NW
Institute-NE,NW,SE,SW Washington Island Southwest-NE,NW,SE,SW
Jacksonport Southwest-NW  

The orthophoto names in bold are those that we currently have on CD or magnetic tape from the NRCS (65 orthophotos). Baileys Harbor West is the only missing orthophoto - it was overlooked in the ordering process, but plans are being made to order a copy from the USGS along with a few other missing but available orthophotos.

Manitowoc County

Manitowoc County DOQQ coverage is complete and available from the USGS (See Figure 7) . We currently have complete coverage on a USGS CD and also some duplicate coverage on CD from the NRCS.

Eleven orthophotos are needed for coastal coverage along the 1000-meter zone (given as Quadrangle Name–Quadrangle Quadrant):

Table 7: Sheboygan County Needed DOQQs
Cleveland East-SW,NW Two Creeks-SE,NE
Manitowoc-SE,SW,NE Two Rivers-NE,SE,SW
Mishicot-SE  
 

Sheboygan County

Sheboygan County DOQQ coverage is complete and available from the USGS (See Figure 8) . We currently have almost complete coastal coverage of the needed USGS DOQQs on CD from the NRCS. We are missing Sheboygan Falls-SE however.

Eight orthophotos are needed for coastal coverage along the 1000-meter zone (given as Quadrangle Name–Quadrangle Quadrant):

Table 8: Sheboygan County Needed DOQQs
Cedar Grove-NE,SE Sheboygan North-NW,SW
Cleveland East-SW Sheboygan South-NW,SW
Sheboygan Falls-SE  

Ozaukee County

We have the complete coverage of SEWRPC orthophotos for Ozaukee County (See Figure 9). Ozaukee County also has 1956 orthophotos from a coastal recession study area (the southern 10 miles of the county).

Twenty orthophotos are needed for coastal coverage along the 1000-meter zone (given as ttrraa: tt=township identifier, rr=range identifier, aa=aerial photo identifier (upper right hand section of two-by-two orthophoto section squares)):

092205    102229    122201
092217    112201    122213
092227    112203    122225
092229    112213    122305
102203    112215    122317
102215    112227    122329
102227    112229

Milwaukee County

Complete coverage is available from SEWRPC orthophotos for Milwaukee County (See Figure 10). We still need to obtain these.


Twenty orthophotos are needed for coastal coverage along the 1000-meter zone (given as ttrraa: tt=township identifier, rr=range identifier, aa=aerial photo identifier (upper right hand section of two-by-two orthophoto section squares)):

082203    072213    062213
082205    072215    062225
082215    072227    052201
082217    072229    052213
082227    062203    052225
082229    062205    052329
072203    062215

Racine County

Complete coverage is available from SEWRPC orthophotos for Racine County (See Figure 11) .  We still need to obtain these.

Ten orthophotos are needed for coastal coverage along the 1000-meter zone (given as ttrraa: tt=township identifier, rr=range identifier, aa=aerial photo identifier (upper right hand section of two-by-two orthophoto section squares)):

032305    032329    042315
032315    042201    042317
032317    042305    042327
032327

Kenosha County

Complete coverage is available from SEWRPC orthophotos for Kenosha County (See Figure 12).  We still need to obtain these.

Six orthophotos are needed for coastal coverage along the 1000-meter zone (given as ttrraa: tt=township identifier, rr=range identifier, aa=aerial photo identifier (upper right hand section of two-by-two orthophoto sectioin squares)):

022305    022329    012317
022317    012305    012329
 


Chapter 3. Estimated Completion Costs of Digital Orthophoto Quarter-Quad Production

The costs of orthophoto production are sometimes shared with agencies interested in seeing the completion of orthophoto coverage for a given area. According to Ted Koch of the State Cartographer’s Office those agencies involved in cost-sharing of the production of DOQQs usually put up enough funds to cover half the cost of orthophoto production. He estimated this figure to be $1020 per orthophoto quarter-quadrangle. So the total cost per unit for orthophoto quarter-quadrangle production is about $2040. He did mention that this figure does not represent total production costs. Additional fiscal resources may be required if a photo source does not already exist for the area (usually the NAPP 1:40000 series) or if additional control information is required. If additional ground control information is needed the added cost would include sending survey crews to collect the information. He also mentioned that with the beginning of the new federal fiscal year in October of 1998 the cost of orthophoto production would probably lower to less than $2000 per quarter-quadrangle.

Based on the cost estimates given above total cost estimates for completion of Oconto and Marinette counties were calculated.

Estimate of Completion Costs for Marinette County:

There are 142 orthophoto quarter-quadrangles in Marinette County, 10 are currently available.
The estimated total cost of production of the remaining 132 orthophotos is:
132 photos * $2040/photo = about $269,280.00

Estimate of Completion Costs for Oconto County:

There are 108 orthophoto quarter-quadrangles in Oconto County, 18 are currently available.
The estimated total cost of production of 90 orthophotos is:
90 photos*$2040/photo = about $183,600.00


Chapter 4. Digital Orthophotos Specifications

USGS Orthophotos
Date:
1992

Naming convention:
The convention is: Oyyxxxzz.aab.

"yyxxxzz.aa" describes the geographic extent of the file where:
yy = SE Latitude of one-degree block in which quad resides.
xxx = SE Longitude of one-degree block in which quad resides.
zz = the 7.5 minute section number of the one-degree block in which the quad resides (reading left to right from the northwest corner).
aa = the quarter of the quadrangle, e.g. nw = northwest quadrant of quadrangle.

b = file type: c for compressed (JPEG format), h for header (ASCII).

Example:
O4408743.nwh
O4408743.nwc

Format:
JPEG

File Size:
Approximately 55MB uncompressed,
approximately 2.6-3.5MB JPEG compressed.

Scale:
1:12 000, 1 meter ground resolution.
3.75 min. longitude by 3.75 min. latitude quarter quadrangle.

Projection and Coordinate System:
Universal Transverse Mercator, coordinates from NAD83. Coordinates in meters.
NAD83 and NAD27 quarter quad ticks are embedded in the image.

Accuracy:
Orthophoto quarter quads meets National Map Accuracy Standards for 1:12 000 scale.

Availability:
Available from USGS in the following formats:
-CD (recordable), 45-50 MB uncompressed, $40
-CD-ROM (quadrangle), 5MB/file (JPEG compressed), $32/1 CD, $42/2 CDs, $52/3 CDs
-ftp (quarter quadrangle), 45-50 MB uncompressed, $40, volume pricing exists
-8mm tape (quarter quadrangle), 45-50 MB, $40, volume pricing.

Data Access:
USGS DOQQs are available from the USGS Global Land Information System.

Sharing Policies:
Public access priced at cost of distribution.

NRCS Orthophotos

Date:
1992

Naming convention:
NRCS uses a file-naming convention based on 1:100000 scale
quadrangle tiles which cover one-degree of latitude and longitude.

The convention is: qaabbccd.EXT

"aabbccd" describes the geographic extent of the orthophoto file, where:
aa = the lower latitudinal boundary of the 1-degree by 1-degree quadrangle.
bb = the easternmost longitudinal boundary of the 1-degree by 1-degree quandrangle.
cc = the index code of 7.5 min by 7.5 min quad in the 1-degree by 1-degree quadrangle, where:
       the numbers 1-8 represent the east-west index identifier
       the letters a-h represent the south-north index identifier.
d = the quarter section of the quadrangle, where:
                    1 = NW 2 = NE
                    4 = SW 3 = SE
EXT- file extension-either .bil (image) or .hdr (header)

Example:
q4586d83.bil
q4586d83.hdr

Format:
.bil

File Size:
41-42MB

Scale:
1:12 000

Projection and Coordinate System:
see USGS information above.

Accuracy:
see USGS information above.

SEWRPC Orthophotos

Date:
1995

Naming convention:
ttrraa.EXT

"ttrraa" describes the geographic coverage of the orthophoto file, where:
tt = township identifier (including a leading zero, if applicable)
rr = range identifier
aa = aerial photo identifier

Format:
.TIF

File Size:
About 30 MB.

Scale:
? 1:4 800 (1"=400’), 2 foot pixel resolution.
A single orthophoto image covers a nominal four-square-mile area representing four US Public Land Survey sections.

Projection and Coordinate System:
Wisonsin Coordinate System, South Zone, NAD27.

Accuracy:
?

Availability:
Available from SEWRPC

Data Access:
$100/CD. CD covers a survey township.
There are 73 master CDs for the 7 county SEWRPC area.

Sharing Policies:
?


Last modified by David Hart on August 2, 1998