Geospatial Imaging Chain Streamlining workflows

Geospatial Imaging Chain Streamlining workflows

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Wendy Watson
Wendy Watson
Vice President
Product Management & Marketing
Leica Geosystems GIS & Mapping

Depending on their needs, people utilize remote sensing and geospatial information in very different ways, but to the same end: informed decision making. To facilitate these decisions, some users need a map, some are seeking only a number, and some a fly-through 3D scene. Others require more details. While varied needs drive the creation of these diverse deliverables, each has a genesis in geospatial imaging

Consider this scenario: a corn farmer buys new land, then grows, ships and sells the corn at a market. Imagery plays a role repeatedly throughout the process; the farmer must have a tax assessment on the new land, the crop must be managed strategically, and then transported on a newly constructed highway to the market in a burgeoning, well-planned suburb. Geospatial imaging contributes to decisions made in each step of this process, although with distinct applications.

Assessing Land Tax
Following the purchase of the farmer’s new land, there was a tax assessment on the parcel. One of the most essential tools for assessment is a map reflecting the size, shape and location characteristics of each parcel under the tax assessor’s control. Using pre-referenced satellite photos of the tax district, the location, dimensions and development of all the area’s properties was extracted in a photogrammetric application, as well as the value of each parcel. All of this information is layered on top of the image to create a tax map. With this tax map, the assessor easily archives and analyses property transfers, records topographical and other features pertinent to the valuation of the land, and develops land value maps. This information assists the assessor to make good decisions when assigning tax rates.

Strategic Farm Management Decisions
Once the farmer completed the acquisition of the new parcel, planning for the new crop commenced. This farmer employs precision farming to improve profitability and reduce risk. The farmer contracted an aerial photography company to periodically capture and reference custom infrared images of the farm. Utilizing these images, in conjunction with global positioning systems and GIS software, the farmer is able to understand site specific information and make better farm management decisions for crop production. A software program highlights various crops, drainage areas, and other features. The farmer identified areas needing special attention, such as fertilization or watering, and recorded the coordinates of these areas. With these coordinates, a GPS system can guide the farmer’s equipment to target key regions of the field. In the short-term, the farmer can use images to track crop health, and plan for precise fertilization that matches crop requirements and prevents over-application. In the long term, the farmer can evaluate the effects of various management practices to promote informed decisions on the use of varieties, products and methods. With precision farming backed by geospatial imaging, the farmer makes decisions that ensure the highest volume and best quality yield, which makes the farmer’s corn very desirable to consumers.

Most Appropriate Highway Corridor
Following the harvest of the farmer’s corn, it was trucked to a market via a newly constructed highway. Geospatial imaging played a key role in determining the route of the highway. The highway planning team required a thorough understanding of the surrounding area’s geography, as well as the environmental and economic impact of its construction. To devise an appropriate path, the highway planning team contracted a plane to fly over the potential pathways with a digital sensor and a LIDAR scanner. The images were then referenced to the ground and to each other, corrected for some distortions in the images. Next, the planners identified all features that needed to be accounted for in the planning and construction of the highway, such as boundaries of jurisdiction, topographical features and natural resources, existing rail lines and roads, and its proximity to commercial and residential areas. With this data, the team could begin to trace potential paths for the roadway and model the impact of each. With this information, the planning team identified each of these features, calculated an ideal path, and presented a map that was used for decision making in the construction of the highway.

Urban Change Detection
At the journey’s end, the corn arrived at a market in a blossoming suburban area. This suburb has grown up quickly, but its growth has been monitored and managed by an urban planning team. The urban planners bought aerial photos and referenced them in-house, which was less costly than buying pre-referenced images. Working with the market developer, the urban planners compared recent aerial photos with those taken over the past thirty years. Potential locations for the market were identified based on location criteria, such as proximity to current and potential transportation routes, public services, suppliers, customers, physical factors and zoning requirements, as well as availability of area for the building and its required parking. The aerial photography oriented the planning team to community growth trends, and helped to determine a location for the market that will be convenient to shoppers for years to come. Using geospatial information, the urban planning team worked with the market developer to decide which site is most compatible with the community’s long-term needs. The market now does swift business with its local customers, who are pleased to purchase the farmer’s fresh corn.

Geospatial Information Workflow
Geospatial information can facilitate better informed decisions, as described in the preceding scenario. How does each of these users of geospatial information progress from the same starting point – geospatial imaging – to such varied ends? There is a workflow that transforms an image into essential information, which enables projects to proceed more efficiently and cost effectively. All activities on a project are related – from data capture, spatial referencing, measuring and analysis to presentation – and ideally each step flows smoothly into the next. Each component of the process should integrate to carry out the goals of the project: capturing the required image, referencing the image to obtain accurate coordinates, measuring it to extract specific data, analyzing the data to discover relationships between image features, and presenting the data in a format that enables good decision making. This workflow – Capture, Reference, Measure, Analyze, and Present – is the Geospatial Imaging Chain. While each of the projects in this scenario progressed through all or a part of the Geospatial Imaging Chain, the hardware, software and activities during each step, and the end results were widely varied.

However, there are impediments to workflow, causing projects to demand more time, energy and money. Geospatial imaging workflows are not traditionally fast or automated, projects spread across different products, data formats and systems can slow productivity and compromise accuracy