Radius and mass of planets will both depend on knowing their distance: The mass calculation requires knowing the size of the moons' orbits, which again requires distance.

Although, come to think of it... If you can get a telescope with good enough resolution, and a spectroscope, and can get a recognizable spectrum off of a moon, to enough precision to get a Doppler shift, you could also determine the moon's orbit (and hence its distance, and hence all the other solar system distances) that way. It probably wouldn't be as precise as radar or a transit of an inner planet, but it probably would take less tech. It's easiest if the moon's orbit is very close to circular, but fortunately, that tends to be true of most moons.