2006-06-13

MAP tool of the day - ADERSHEET (rubbersheet)

from MAP3D 2006 help:

ADERSHEET (Rubber Sheet command)
Performs rubber sheeting on selected objects
Rubber sheeting is a nonuniform adjustment of a data set based on the movement of known control points to new locations. For example, data collected by aerial survey may be inaccurate because of flight alignment and camera inaccuracies. By comparing this data with accurate ground survey data, the aerial data can be stretched or rubber sheeted over the accurate data using control points and monuments common to both data sets.
Use rubber sheeting when you want two or more different data sets from different sources to align geographically: for example, when stretching a new subdivision map into a preexisting parcel map.

Note that objects that have a given shape, such as circles, arcs, and ellipses, retain their original shape.

Warning
Use rubber sheeting only when it is absolutely necessary, because it can severely compromise the accuracy of your data.
Because rubber sheeting is not a linear transformation, it is difficult to reverse the effects of the transformation and return a drawing to its original state. You should save a copy of your original drawing before you perform a rubber sheeting operation.

Changing Scale
Do not rubber sheet two maps drawn at different scales. If you do, the command matches objects and changes the original scaling of text and blocks to match the new scaling, which can change data significantly. You should use rubber sheeting as a last resort after exhausting other methods of object editing and coordinate adjustment.

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