## Format for the Spacecraft VLBI Observations

columns 1 Spacecraft Acronym 2 Planet 3 Year 4 Month 5 Day 6 Time (hh:mm:ss) 7 Correction to DE405 (milli-arcseconds) 8 Measurement uncertainty (milli-arcseconds) 9 Angle (degrees) of VLBI baseline on plane of sky, relative to celestial equator A VLBI observation is a one-dimensional angular correction. The position of the planet is observed to be displaced from the base ephemeris (DE405) by the measured correction, "Meas", along a line which makes an "Angle", measured counter-clockwise from the right ascension axis. I.e., for theta=0, aldel is the equivalent of an observation in right ascension only; for theta=45, aldel is partioned equally, sqrt(0.5) each, into right ascension X cos(dec) and into declination, with 100% correlation between the two.