Object Attributes - Geo-referencing

Version 7 now has full Geo-Referencing capabilities as a result of the inclusion of the European Petroleum Survey Group (EPSG) Geodetic Parameter Data Set, a SQLite database that is installed with the software. The database gets updated approximately three to four times a year, with intermediate versions. The EPSG tables define numeric identifiers (the EPSG code) for many common projections and associate projection or coordinate metadata (such as measurement units or central meridian) for each identifier.

The object attribute window shows the current coordinate reference system in use. If using Object sd files from pre-7.0 versions of Fledermaus this will be converted to WGS 84 or a projected Mercator coordinate reference system until updated by the user (The user must then resave the object if the user wants to retain these changes).

 The Coordinate Reference System (CRS) can contain a vertical component within a compound CRS. This can be overridden with a local vertical units. Otherwise units are generally set by the outermost unit specifier - e.g. for projected CRS's this is the linear unit (meters or US survey feet being the most common) and for the lat-long geographic CRS, it is an angular unit (degrees or sometimes grad units).

Re-selection of CRS is available with the (...) push-button (Select Coordinate System Dialog) - this will usually make the object un-displayable. This is a change of the definition of the CRS of currently loaded data points. To re-project you must select the CRS in the Scene geo-referencing tab.

All Coordinate Systems can be edited using the Edit Coordinate System Dialog.