Scope of Document

This document defines an open encoding format for terrain databases. This format, when designed and implemented, will enable a quick, economic, and efficient use of terrain databases (TerrDBs). However, since industry does not require applications to be standardized, data interpretation is not addressed in this document.

Due to the wide variety of system objectives and constraints, details of how the database is packaged into files are not covered in this specification. Rather, a standard yet flexible framework is defined such that all databases describe the file division in the same way and format. As a result, how and why the data is packaged across files is transparent to an application.

With a standard format specification (including binary encoding) and packaging framework, all applications can read the database content in the same manner. That is, whether a TerrDB is packaged across 10 files or 10,000 files, the way in which the file structure is defined in the database and consumed is the same. Similarly, packaging of different databases could be performed with the same tool by setting different parameters.

ARINC Specification 813 includes the following:

• Metadata specifications

• Features and attributes derived from RTCA DO-276/EUROCAE ED-98

• Coding derived from RTCA DO-291/EUROCAE ED-119

• Physical file format specification

• File packaging framework

• Cyclic Redundancy Check (CRC) algorithm specification

• Dataload considerations

• XML schema

• Data indexing

• Use of data compression

• Data optimizations