Excavation unit is a Class which defines artificial Site objects and subdivides the Archaeological Object into smaller units. The Excavation unit is primary an excavated volume used for collecting Finds.
The Excavation units are:
Artificial stratum which is an artificial excavated volume. The size, orientation and position is decided from the Square.
Free formed stratum which is an artificial excavated volume limited by a boundary that decides size and position.
Excavation units are quite uncomplicated excavated volumes. It is normally very effective to use Excavation units that have references to Squares. Free formed stratum you preferably use when you are convinced that the world can not be described with a Grid. The main disadvantage with Artificial stratum is that it can cut through several different Archaeological Objects. And the disadvantage with Free formed stratum is that it is more difficult to understand vertical Find contexts.
Measure Artificial stratum:
Plan the Measurement session.
Measure the Stratum by placing the Measurement point somewhere within the Square. The Measurement point has the code 1 E square identity.layer identity. 1 stands for Point object , E is the code for the Class Excavation unit, square identity is the Object reference to the corresponding Square and Layer identity is a reference to the Layer that the Excavation unit is part of. The Excavation unit receives Identity from the available Point number.
When you import the Measurement, the Excavation unit is created. The Excavation unit's Geometry is decided when it is automatically linked to a copy of the Reference square's GeoObject. The copy inherits the Excavation unit's Z-value and the Excavation unit's Identity becomes the current Point number. The System creates a Contextual relation between the Square and the Layer.