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overshoot - [data structures] The portion of an arc digitized past its intersection with another arc.
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That portion of an arc digitized past its intersection with another arc. See also Dangling Arc.

See Also: dangling arc
[data structures] The portion of an arc digitized past its intersection with another arc.

Overshoot: Situation where a digital line extends past the intended boundary line. This extension past the intended juncture point is called a dangle.
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This is an overshoot error, a type of error that is often found in line work imported from CAD programs or digitized without using snapping to control the connectivity of the line features.

Undershoot - a topological error that occurs when an arc which is supposed to intersect with another arc fails to reach that arc. See also ~.

~). A dangling arc is not always an error. For example, dangling arcs can represent cul-de-sacs in street centerline maps. See also dangling node. dangling node The endpoint of a dangling arc not connected to another arc.

The program gives warning when significant ~s appear in the resulting surface and higher tension or smoothing should be used.

August 2 - Air France Flight 358 bursts into flames after ~ing the runway at Toronto Pearson International Airport; all aboard survive.
August 2 - The Dominican Republic-Central America Free Trade Agreement (CAFTA) is signed into law in the United States.

~s and undershoots usually occur when features are entered without the aid of a snapping routine. The feature vertices extend beyond (~s) or just short of (undershoots) their intended location. Topological functions can clean up these errors when you define a distance tolerance.

This error is called an "undershoot" when the lines do not extend far enough to meet each other and an "~" when the line extends beyond the feature it should connect to (Figure 4.13 "Common Topological Errors").

Most GIS software will clean up undershoots and ~s based on a user defined tolerance, e.g. distance. The definition of an inappropriate distance often leads to the formation of bow ties or weird polygons during topological building.

Low-pass filtering and resampling often cause ~, which increases acutance, but can also reduce absolute gradient, which reduces acutance. Filtering and resampling can also cause clipping and ringing artifacts.

during this topology generation process, problems such as ~s, undershoots and spikes are either flagged for editing by the user or corrected automatically ...

Snapping is an important control in the environment. It will assure that features snap to each other, and that dangles, ~s, gaps, or slivers are avoided.

In this graph, the neighboring values for any point X between 0 and 1 are 1, 0, 0, and 0. All "interpolated" values, however, are negative. In a sense, the high value of 1.0 at X=-1 "~s" as it descends to the value of 0.0 at X=0 and then "recovers" to the value of 0.0 at X=1.

The January and April ~s in the modeled data are probably due to the simple bucket-style soil hydrology used by the Forest-BGC model, which tends to produce a faster and more pronounced response to precipitation events than more complex subsurface-flow-based soil hydrologies (Nemani et al.

Errors such as undershoots and ~s must also be removed. For scanned maps, blemishes on the source map may need to be removed from the resulting raster. For example, a fleck of dirt might connect two lines that should not be connected.

If the total curvature inside the region is negative, the strip will curl around further than necessary to close. The curvature is negative, and is measured by the angle by which the curve ~s.

One of the commonest errors when digitising data occurs when there is a slight inaccuracy in the start or end point of a line. This can result in the linework not being correctly joined up. The line can form an undershoot or an ~ (see diagram below).

system overlays, each of which is a single or set of multiple layers within the spatial information system. 4) Also refers to the intersection of two polygon layers to make a third composite overlay (i.e. soils overlaid with land use to define runoff conditions). See Intersection.
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See also: See also: What is the meaning of Model, Map, Coordinate, Area, Polygon?

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