Experimental validation of a dual uplink multifrequency dispersive noise calibration scheme for Deep Space tracking

Abstract

[1] We discuss the implementation and effectiveness of a dispersive noise multifrequency calibration scheme for Deep Space tracking. We show that the combination of two phase-coherent links at X band and Ka-band, with two separate uplink carriers, can provide an effective plasma and ionospheric noise removal, in the order of 75% of the plasma noise affecting the Ka-band link. This algorithm, which we refer to as "Dual Uplink, Dual Downlink", shows a modest loss in the radio link stability, if compared to the complete, state-of-the-art calibration achieved by a more complex radio system, which supplements the two separate uplinks and downlinks at X band and Ka-band with an additional "cross-link" (X-up/Ka-down). The calibration accuracy of these two algorithms is thoroughly compared to define their advantages and shortcomings. Finally, Cassini's multifrequency tracking data acquired in 2002 during a General Relativity solar conjunction experiment aimed at the estimation of the parametrized post Newtonian parameter were reanalyzed to assess the capability of the Dual Uplink, Dual Downlink calibration algorithm to support accurate radio science experiments.Citation: Mariotti, G. and P. Tortora (2013), Experimental validation of a dual-uplink multifrequency dispersive noise calibration scheme for Deep Space tracking,

The effect of Jupiter oscillations on Juno gravity measurements

“…A 0.003 mm/s at 1000 s integration time could be assumed for the two-way range rate measurement accuracy. For white noise, this scales to 0.012 mm/s at 60 s, and 0.03 mm/s at 10 s. These expectations for Juno's Ka band Doppler system are supported by the analysis of Cassini cruise data (Mariotti and Tortora, 2013). The simulated value of 0.020 mm/s at 60 s is larger than the expected performance of a Ka-Ka two-way coherent radio link in order to account for some variability with tracking condition (at low Sun-Earth-Probe angles the plasma noise dominates and the stability of the link is reduced, see Iess et al, 2014).…”

Two Years of Observations of the Io Plasma Torus by Juno Radio Occultations: Results From Perijoves 1 to 15

“…The methods summarized in Section 2 and detailed in Phipps et al (2019) were used to process gravity science data from PJ10, PJ11, PJ14, and PJ15, to generate total electron content profiles of the Io plasma torus, and to determine best-fit parameters for a model of the density distribution in the Io plasma torus. Phipps et al (2019) states "to determine the X-and Ka-band frequency residuals, the X-and Ka-band Doppler observables (f obs ) are combined to remove the effects of plasma noise (e.g., Mariotti & Tortora, 2013), and adjustments are applied for Earth's ionosphere from GPS and troposphere either analytical models or water vapor radiometer measurement (when available). The spacecraft trajectory and Jupiter gravity field are then estimated using the calibrated Doppler observables, which are then used to compute the the expected frequency (f comp )."…”

Calibration Techniques for Studying Venus and Mars Atmospheres

“…However, the measurements do not contain only the atmosphere information. The propagation of the radio signal is affected by interplanetary plasma along its path (which can not be removed in this investigation, since multiple frequency experiments would be required [19]), as well as Earth's ionosphere and troposphere, and errors related to the spacecraft clock, trajectory, and thermal noise [20]. The calibration process is a crucial step of this work, since it aims to compensate all the noises and errors, in order to obtain measurements characterized only by the target's atmosphere information.…”