Visualization of numerical data using 3-dimensional graphics is not a new concept. For many years, devoted users of spreadsheet programs such as Lotus, Quattro, and Excel have been able to view their data in a 3-dimensional format. For many applications in the industrial arena, these 3D images reflecting straight data, with no correlation to actual map positions, fulfilled their purpose of graphically illustrating the relationship between 3 points.
    As GIS technology has continued to expand, so has the need for 3D imaging that adequately links static data with other sources of information to give a total picture. "In agriculture, yield data (for example) has been interpreted as points on a map. A large volume of points with different colors representing different yield values becomes confusing rather quickly," said Max Crandall, Ag Marketing Manager for ESRI.
    "The next step up is 2-dimensional visualization, which uses a raster format and puts point values into ranges." Crandall then uses software to contour the values so that they are easy to see.
    According to Crandall, 3-dimensional visualization, in essence, gives the same results as 2D, but utilizing a Triangular Irregular Network (TIN) to map the ranges, with high yields represented as peaks, and low yields represented as valleys. This is done using ESRI's ArcView 3D Analyst.
    World Construction Set (WCS) has been using 3-dimensional images as tools for geological and environmental visualization since the early '90s. "It started as an in-house tool," said Gary Huber, software developer for WCS. "It was so well received in the industry that we had enough outside demand to produce a commercial version." What resulted is a photorealistic terrain visualization and rendering software with professional level animation that has a solid scientific background. Questar Productions has recently released version 4.0.
    Although the major users of WCS are in the electronic game development, architecture, and engineering fields, there are already solid applications in the agriculture and timber industries. "WCS is used extensively as a planning tool," said Huber. "Our software can combine satellite images with GIS and drape them on a terrain map to give you a graphic picture of what a planned development will actually look like." According to Huber this is a very useful plan- ning tool for the vineyard industry. "They can see how a particular planting will look given certain criteria, and have the opportunity to move things around. If we give it different data and decisions, it will show the different outcome."
    WCS has tools needed to take the digital information about your farming operation and apply it visually. You can clear the trees from a building site, build orchards, vineyards, or terraced fields. The color maps in WCS can be applied to project satellite or other images into landscapes, or specify exact placement of ecosystems. "You can create an image of a farming operation today, and bring it forward to create a future scenario," said Huber. "WCS can even animate the view, so it appears as if you are flying through or around the site."
    Glenn Hanson of Midwest Ag Services in Jamestown, North Dakota, has taken 3D visualization one step further. Eight years ago, he began to experiment with GIS, GPS and other precision agriculture technologies. "Four years ago, I heard about a study at North Dakota State University that took elevation into account when determining soil connectivity," he said. Taking measurement of the soil at varying depths allows him to determine soil texture. This allows him to delineate differences in areas of a particular field.
    Hanson has incorporated this technology into his approach to soil fertility and inputs. Hanson has written his own program, based on the Rockwell Vision core. "My goal is to automate processing for the entire field," he said. The program generates a list of maps to consult for each field: a 3D map, a contour map (2-dimensional), satellite image, soil connectivity, yield maps, and fertility.
    "We use an elevation surfer to obtain a 3D map of a field. We look for hilltops, ridges, and depressions," he said. The 3D maps also show slope, as to how the features lay in a particular field. "The elevation surfer, overlaid with satellite image, yield maps, and other information allow us to look for patterns within a field. We will then divide a field into 5-8 management zones, based on these results," said Hanson. "We don't rely on the same layers of information from all fields. They are weighted to confirm correlation."
    "We've had very positive reception from our growers," he said. "Our biggest obstacle is utilizing existing precision technology to lower the input on crops." He pointed out that farming practices in North Dakota and the upper great plains are much different from the corn belt. "Because nitrogen is our biggest input, we must soil sample every year," he said. "We did 5 fields last spring, and 3 out of the 5 reduced their inputs enough to pay for the extra technology costs, plus allow for more inputs in areas capable of higher production," he said.
    Hanson is still working the bugs out of his program, but he is hoping to be able to automate the process. "We want to be sure that it is based on sound agronomics, but will still treat every field as unique."
    "The third dimension can be used for any number of agronomic variables," says Crandall. "From the farmer who works with data in a macro sense to the scientist who is using micro data, it can be useful."
    However, Crandall cautions that the ESRI ArcView 3D Analyst software is "...not for the faint of heart." Because of this, ESRI has formed a network of business partners, who utilize various ESRI software tools in their proprietary programs.
    One of these business partners is AGRIS Corporation, and their AgLink software product. John Willett, Software Test Engineer with AGRIS said that 3D mapping can be used with many types of data. "The most common use of 3D with AgLink is in the use of point data, whether it is yield, soil nutrients, or other information," he said.
    "Statistically, 2D is adequate," said Willett. "The 3D image allows you to easily see what needs more attention and what areas are exceeding goals." The ability to rotate the 3D image on an X or Y axis or Z angle is also quite useful. "It gives a more visual representation. It's like being able to see across the field," said Willett. "It is sometimes difficult for a farmer to look at a 3D yield map and understand that the differences in a 3D map represent yield and not actual surface elevations."
    The one area of general agreement is that 3D is not yet being utilized very extensively in the agriculture sector. Although very useful as a planning tool, especially when combined with satellite images and topographical maps, the use of 3D for agriculture applications is still in its infancy. "It's similar to the tractor replacing the horse," said Crandall, "And that took 35 years!"    Hanson said that the final determination of success for any of these programs comes down to this: "Every farmer wants to know," he said: "How does it work on my farm?"

About the author:
Marj Nelson is a freelance writer specializing in topics related to agriculture. She owns Heartland Services, a marketing/consulting business she started in 1987.

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