Select the name of a file containing the DSN Radio Source Catalog as described in the DSMS Telecommunications Link Design Handbook (810-005, Rev. E) 107 Radio Source Catalog. This file provides the locations of quasars which are used during the processing of DSN Delta DOR (Delta Differenced One-war Range) measurements. Delta DOR measurements provide complimentary plane-of-sky information to the more commonly used line of sight measurements (range and Doppler) for deep space navigation.