Addressing multiple-scale output requirements

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Addressing multiple-scale output requirements

Finding the "Lowest Common Denominator"

Interest to Save Money
Government is faced with providing much better service to the taxpayers while at the same time having to live within their respective means. Raising taxes to pay for incremental products and programs is political suicide. Obviously, doing more with less has hit government as hard as competing utility companies learning to deal with deregulation. Government especially is looking for inexpensive ways to get into GIS / GIT through partnerships however, interactions with the private sector is new territory for many agencies. In many cases, polarization can occur as both, or multiple, parties seek fairness in obtaining an agreement for required products.

Utilities and telecommunication companies as well are seeking to reduce costs and increase revenues, especially now that deregulation is here. The idea of giving away an existing land base or paying the full cost of a custom land base is not the way that most companies are thinking. Given all the difficulties, how can an agency or company go about getting started with a cost-sharing project? A first step might be to analyze what the "lowest common denominator" is.

First Steps and Cost Sharing Analysis
MichCon and it's land base vendor in 1997 started a project of aerial photography and GPS ground control for the Traverse City area of the lower peninsula of Michigan. From that area of approximately two townships digital orthophotography was produced along with a digital terrain model (DTM). MichCon along with its vendor attended a conference in Michigan known as Imagin, which brings governmental agencies together for GIS education. At this event, MichCon's plans were shared and discussions started with two counties who were part of the Northwest Michigan Council of Governments. MichCon and its vendor then started developing the opportunities that were available and different options available. The following table suggests some of the options and potential cost sharing opportunities.

GIS Component	Opportunity For Cost Sharing
Aerial Photography	High
GPS Ground Control	High;
DTM	High
Digital Orthophotography	High, at 1.5 foot ground resolution; 4 square mile area; 1”=400’ digital orthophotograph; flight at 15,840 which results in an aerial negative scale of 1”=2,640’; each 1”=400’ ortho = 59mb.
Vector Land Features - Planimetric	Medium to Low
Vector Land Features - Cadastral	Medium to Low

Digital Orthophotography

What is it?
In the deregulated utility and telecommunications industry, companies require land-base mapping that is accurate and complete. The search is on for low cost land base mapping that can support detailed planning especially in areas where customer density is suburban or rural. Digital orthophotography meets these criteria. Until the later 1990's, however, utilities required large, powerful, expensive computer systems to manage and manipulate digital orthophotography and other high-resolution imagery. With the advent of powerful, low cost computer systems, digital orthophotos became a viable alternative to traditional vector land-base maps in AM/FM/GIS systems. A digital orthophotograph is a geographically referenced high-resolution scan of an aerial photograph. The distortions caused by minor anomalies in the camera lens, relief on the earth's surface, and tip and tilt of the airplane at the moment of exposure is removed through a rigorous mathematical process. The resulting geo-referenced image provides an excellent land-base map for AM/FM/GIS applications. As accurate as vector based maps, digital ortho's provided the added benefit of being a much more complete source of information.

Due to the high cost of vector based mapping, many utilities are reluctant to update their land-base maps. Less costly to create in the first place, digital orthophotos also have the advantage of being less costly to update than their vector predecessors. Unless major construction has occurred, the DTM surface created during the original orthophoto project can be reused, saving considerable project fees. Typically, the ground control information can also be reused in the update digital orthophoto project. These factors combine to create update project fees as much as 50% lower than the original project costs.

Noted below is a sample digital orthophotograph. Some degradation of the resolution will be noted due to dpi constraints.

1.5 Foot Ground Resolution - Zoomed in area
Common "Ingredients" Reached
Our land base vendor started working with us on contractual possibilities for producing digital orthophotograph land products for the rest of Northern Michigan after great interest was expressed from several of the county governments. MichCon's initial agreement with Emmet and Charlevoix Counties was fairly complex given the fact that an agent for the State of Michigan was involved in a three-way partnership. All products leading up to and including the digital orthophotography were included in the cost sharing agreement.

Since then MichCon has reached agreement with Otsego, Grand Traverse and Antrim Counties with other counties being targeted for additional discussion.