The WIDAR binary lag set format is an intermediate output format for files produced by the WIDAR correlator backend. The format is designed primarily for WIDAR system diagnostics, and is not appropriate for science purposes. Files produced in the format are intended to provide a record of the lag sets assembled by the backend from lag frames received from the WIDAR baseline boards, without loss of any information carried by the lag frames. Nearly all of the fields in the lag frames comprising a lag set are recorded in the binary lag set format; the only exceptions being those fields that that are constant in all (valid) LTA output data frames. Several additional fields are present in the binary lag set format for completeness.

The format described in this document is intentionally very similar to the LTA output data frame format, and no attempt is made herein to describe in much detail those fields appearing in both formats. Please refer to the LTA Controller FPGA RFS document^[1] for further information on the LTA output data frame format.