Among the various Planet DMS data files, six categories of data are handled by the Planet Reader:
- height
- clutter
- CDMA
- coverage array
- vector data
- validation
The first four categories are stored as raster files.
The CDMA and coverage array rasters are organized into two logical parts: a header and a raster. The header contains information that defines the raster’s general characteristics, including the easting and northing dimensions. There is only one header per file. The raster section of the file contains the points of data. The height and clutter raster files contain only points of data. The general characteristics of these rasters are stored in a separate index file. The validation data relates to the coverage array. Each data sample in a raster file is translated to a part of a single three-dimensional (3D) FME raster feature.
For each of the first five data categories, there exists a designated folder and accompanying data files. The sixth type, validation, is stored within the coverage array folder. It is also possible for a data category to contain subfolders of data files. Height, clutter and vector categories can have /user subfolders. Clutter can also have /separation, /orientation, /street_widths and /bldng_heights subfolders. The CDMA folder contains a subfolder for each set of CDMA data files. All of these data categories and their folders are located in one main folder.
Planet DMS data comes with a project definition file in the main folder. The records in this file contain <key, value> pairs: the key follows a standard naming convention for each Planet data category; the value is a folder address. Therefore, for each data category existing in the main folder, a standard key in the project definition file must exist in order to obtain a folder address to read.
FME considers the project definition file to be the dataset. When the Planet reader is called to read data, this dataset and any of the six Planet data categories (height, clutter, CDMA, array, vector, and validation) must be defined in the mapping file before reading can be performed. The data categories are listed in the mapping file as Planet feature types. These feature types are referenced to project definition file keys which are used to search the project definition file. When a matching key is found in definition file, the appropriate value (i.e., data folder address) is retrieved and the data can be read.
The following table gives an overview of the Planet data categories that have been defined as feature types.