Frequency calibration of the SWI instrument on-board of JUICE using SpaceWire Time-Codes

The Sub-mm Wave Instrument (SWI) is one of the scientific instruments on board of the JUpiter ICy moons Explorer (JUICE) mission. It is a sub-millimeter wave spectrometer with a very high spectral resolution. In order to calibrate the location of the spectral bands the frequency of the instrument´s ultra-stable oscillator (USO) has to be monitored to very high accuracy. The instruments on board of JUICE are connected through a SpaceWire network which is used for the transmission of the scientific data to the on-board memory as well as to control the instruments and for the transmission of instrument housekeeping data. The objective of this paper is to investigate if SpaceWire Time-Codes can be used to calibrate the USO frequency of the SWI to the required accuracy. It presents an end-to-end budget of the elements contributing to the error of the frequency calibration with the reference on ground.