Describe do dynamics here.

Adjusts pointing on sigmas

vsig  - set's sigmas on spacecraft vector
psig - pointing
change reference frame
introduce overlap with images (don't move too much)

Original intent, put into nominals (before and after) the position difference in inertia space between the current image and after (+- 2)  All images within a timespace (30 min)

Run after make_sumfiles

 ipl2sco - reads nominals, uses the nominal s/c position so it doesn't go too far
      same with velocity too

Downtrack, cross track, radial =- not done (used to be x, y, z spacecraft)