# DTED – Military Elevation Data¶

Driver short name

DTED

GDAL supports DTED Levels 0, 1, and 2 elevation data for read access. Elevation data is returned as 16 bit signed integer. Appropriate projection and georeferencing information is also returned. A variety of header fields are returned dataset level metadata.

## Driver capabilities¶

Supports Create()

This driver supports the GDALDriver::Create() operation

Supports Georeferencing

This driver supports georeferencing

Supports VirtualIO

This driver supports virtual I/O operations (/vsimem/, etc.)

Elevation data in DTED files are organized per columns. This data organization doesn’t fit very well with some scanline oriented algorithms and can cause slowdowns, especially for DTED Level 2 datasets. By defining GDAL_DTED_SINGLE_BLOCK=TRUE, a whole DTED dataset will be considered as a single block. The first access to the file will be slow, but further accesses will be much quicker. Only use that option if you need to do processing on a whole file.

### Georeferencing Issues¶

The DTED specification (MIL-PRF-89020B) states that horizontal datum shall be the World Geodetic System (WGS 84). The vertical datum is defined as EGM96, or EPSG:5773. However, there are still people using old data files georeferenced in WGS 72. A header field indicates the horizontal datum code, so we can detect and handle this situation.
• If the horizontal datum specified in the DTED file is WGS84, the DTED driver will report WGS 84 as SRS.

• If the horizontal datum specified in the DTED file is WGS72, the DTED driver will report WGS 72 as SRS and issue a warning.

• If the horizontal datum specified in the DTED file is neither WGS84 nor WGS72, the DTED driver will report WGS 84 as SRS and issue a warning.

### Configuration options¶

This paragraph lists the configuration options that can be set to alter the default behaviour of the DTED driver.

• REPORT_COMPD_CS: (GDAL >= 2.2.2). Can be set to TRUE to avoid stripping the vertical CS of compound CS when reading the SRS of a file. Default value : FALSE

### Checksum Issues¶

The default behaviour of the DTED driver is to ignore the checksum while reading data from the files. However, you may specify the environment variable DTED_VERIFY_CHECKSUM=YES if you want the checksums to be verified. In some cases, the checksum written in the DTED file is wrong (the data producer did a wrong job). This will be reported as a warning. If the checksum written in the DTED file and the checksum computed from the data do not match, an error will be issued.

## Creation Issues¶

The DTED driver does support creating new files, but the input data must be exactly formatted as a Level 0, 1 or 2 cell. That is the size, and bounds must be appropriate for a cell.

• Implemented as gdal/frmts/dted/dteddataset.cpp.