6.5 Auxiliary Data

6.5 Auxiliary Data

An image scene is composed of multiple files, each of which is composed of multiple records. Data other than image data in the files, are called auxiliary data.

The auxiliary data involves descriptions of file, image data, platform, sensor, data processing and other data, including telemetry.

Figure 6.5.1 shows the basic configuration of the World Standard Format or LTWG format with the files and the records. The files and the records in the figure are as follows.

Reader file: header record, ancillary record, annotation record etc.
Image file: image record (line information and spectral data)
Trailer file: trailer record (quality of data)
Supplemental file: information on satellite, detector, data correction etc.

Table 6.5.1 shows the contents of auxiliary data. There is a text record in which any comment can be described. In the LTWG format, the text record is located in the volume directory file.

The LTWG format has no fixed specification on the content of each record, while the CEOS Format (Committee on Earth Observation Satellite) specifies the standard content of a record, which will be utilized more than LTWG in the future.