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Introduction - Additional Notes...

Whenever you are using the dialogs that are part of this extension, you can continue to use standard ArcView tools, buttons, and menus along with the tools provided on the dialogs. Whenever possible, however, you should try to use the dialog tools, because occasionally you might unknowingly confuse the dialogs if you change some condition within ArcView (this is particularly likely to happen if you save the project or change the shapefile or table's edit status while using the Parcel Editor or Attribute Entry dialogs). If you are using the extension in conjunction with a project or extension that has customized versions of standard ArcView tools, you may want to use those tools instead. For instance, when using the old library version of the MassGIS DataViewer, the Pan, Zoom In, and other zooming tools are customized to correctly update the library themes in the View (especially image themes) and the zooming tools on the Parcel Editor dialog may not work as expected.

This extension was developed for use with data stored in the Massachusetts State Plane Coordinate system and has not been tested extensively with data stored in other coordinate systems, including decimal degrees. Most of its functions should work fine with any data stored in coordinate systems such as state-plane or UTM coordinates. Some of the scripts are customizable with minimal effort to work with other coordinate systems (for example, the script dkOT.ProjectPoint). Many scripts may give unpredictable results when used with decimal degrees (lat-long) data (like the ESRI sample data), especially scripts that deal with length and area concepts. The extension has not been tested with ‘projected’ data, i.e. data stored in decimal degrees and viewed in another projection.

It is important to be familiar with the projection you are using. Even a State Plane coordinate system will have variations in angle and distances across its intended area. Generally, if you are using an appropriate projection for your study area, distance and area measurements should be fairly accurate across a small area (like the extent of a property survey). In some coordinate systems, angles at one end of a state will differ from the other end. When entering surveys, you will probably need to rotate them anyway, using background data as a guide. You should familiarize yourself with your coordinate system's variations so you'll know whether to trust that the lengths given in your surveys will be correctly drawn on your map.

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This document was created by DEM/ NWF. Contact: DEM/ NWF.