There are two components to the CART system.
The automatic drafting component reads a database containing points and related information and turns it into a CAD Model fully linked to the database that drew it and optionally, to any other databases specified.
The data entry tools create the necessary database from a variety of input systems including total station survey data, plane-table measurements, hand measurements using running dimensions, paper drawings, photographs, camcorder or still CCD images and drawing files from any vector based CAD system.
What is a CAD Model?
Ideally a CAD model consists of a vector drawing where each object is uniquely identified and linked to an associated database. These links provide the model with intelligence such that each object "knows" what it is and where to find further information about itself.
There are two components of the CART system. The first is automatic drafting software that takes a database containing points and pertinent information about those points and from it, generates an Autocad model. The other component is a suite of tools to build that database from whatever data sources are available.
The database consists of a few essential fields that describe object location and type and give it a unique name. The optional fields are used to describe any aspect of the object that is of interest to the recorder. When the model is generated, these fields are used, in any combination desired, to create block or layer names, attribute values and Xdata links to the CART database and/or to any other database associated with the objects modelled.
The result is a CAD model composed entirely of unique objects, each with at least one link to a database that further describes it. The engines driving this tool are Autocad and its add-on Data Extension (ADE), with the CART add-on as a front end.
The models created by the CART system need never be saved as Autocad drawings as they can be re-generated and, if necessary plotted, at any time, in whole or in part, and with different parameters if desired. The huge and slow FM drawings we are used to are thus unnecessary and both data storage and operator time can be significantly reduced. CART databases can be saved as comma delimited text files, readable by all computers, and can even be e-mailed as flat files to other CART users for generation.
CART also provides access to the data linked to the drawing by providing
pre-defined queries of often used functions, such as those requesting information
about a particular object or area. As well, user-specific queries can be
defined and stored for future use using Standard Query Language (SQL)