2DC: 2D Coordinate Group

This record specifies the beginning of a 2D coordinate observation set.

The format for a 2D coordinate observation group is as follows:

2DC [optional sigma ID]
[Set of 2D coordinate records]
[Covariance matrix header record]
[Matrix elements records]

The "Set of 2D coordinate records" must contain only PL, NE, or XY coordinate records. It may also contain HI, HT, 4PAR, and 7PAR records.

The "Covariance matrix header record" can be one of the following records: COV, WGT, CORR, or GENC.

The matrix elements records are set up as described in Input Matrix Formatting.

The format of the 2DC record is as follows:

Columns 002-005: 2DC
Columns 007-009: Sigma record identifier (see the SIGM record).