Voyager near simultaneous ranging transfers

During testing of near simultaneous ranging techniques, a major shortcoming of the standard DSN uplink transfer procedure was uncovered. Use of the standard procedure resulted in loss of phase coherence between received and reference range codes for the round trip light time following a transfer. The philosophy behind, and the operational procedure developed for near simultaneous range transfer is reported for a new uplink transfer procedure that will enable the DSN to generate good range data during the interval from transmitter off to loss of the coherent downlink.