MORE Review of Requirements L. Iess

With WVR Dish deformations not included

Proposed configuration of the onboard radio system X Ka KAT+SSA XTWTA KaTWTA DST 7.2 GHz 34.3 GHz 8.4 GHz 32.5 GHz No intermodulation, larger output power, larger data rate Simpler testing procedures Onboard range delay calibration Simpler interfaces 32.5 GHz MORE Target accuracy:  f/f = at s  = 10 cm  y (1000s)=  1.5 micron/s  1.5 mm in 1000 s

Plasma noise cancellation Multi-frequency radio link (two-way) Target accuracy:  f/f = at s  = 10 cm KAT XSSA KaTWTA DST 7.2 GHz 34.3 GHz X Ka 8.4 GHz 32.5 GHz  y = is equivalent to a one-way range rate of 1.5 micron/s The corresponding one-way displacement in 1000 s is 1.5 mm Original configuration – MORE EID-B

Cancellation of plasma noise with a multifrequency link [Bertotti, Comoretto, Iess, 1993] X/X Doppler/range observable X/Ka Doppler/range observable Ka/Ka Doppler/range observable Three unknown quantities: non-dispersive term ( ) uplink plasma ( ) downlink plasma ( )

Cancellation of plasma noise (cont.) Conclusion: The Ka/Ka link provides the crucial observable and needs the highest accuracy.