Accession Number : ADA484955


Title :   A High Performance Frequency Standard and Distribution System for Cassini Ka-Band Experiment


Corporate Author : CALIFORNIA INST OF TECH PASADENA JET PROPULSION LAB


Personal Author(s) : Wang, R T ; Calhoun, M D ; Kirk, A ; Diener, W A ; Dick, G J ; Tjoelker, R L


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a484955.pdf


Report Date : Aug 2005


Pagination or Media Count : 7


Abstract : This paper provides an overview and update of a specialized frequency reference system for the NASA Deep Space Network (DSN) to support Ka-band radio science experiments with the Cassini spacecraft, currently orbiting Saturn. Three major components, a Hydrogen Maser, Stabilized Fiber-Optic Distribution Assembly (SFODA), and 10 Kelvin Cryocooled Sapphire Oscillator (10K CSO) and frequency-lock-loop, are integrated to achieve the very high performance, ground based frequency reference at a remote antenna site located 16 km from the hydrogen maser. Typical measured Allan Deviation is 1.6x10-14 at 1 second and 1.7x10-15 at 1000 seconds averaging intervals. Recently two 10K CSOs have been compared in situ while operating at the remote DSN site DSS-25. The CSO references were used operationally to downconvert the Ka band downlink received from the Cassini spacecraft in a series of occultation measurements performed over a 78 day period from March to June 2005.


Descriptors :   *DEEP SPACE , *KA BAND , ANTENNAS , ASSEMBLY , FIBER OPTICS , HIGH FREQUENCY , MASERS , NETWORKS , OCCULTATION , SPACECRAFT , STANDARD DEVIATION


Subject Categories : Astronomy
      Radiofrequency Wave Propagation
      Unmanned Spacecraft


Distribution Statement : APPROVED FOR PUBLIC RELEASE