QUESTION:
The day after the landing, a scientist used a diagram on TV to show
lines-of-sight to quite a few landmarks visible in the lander images, and as
I remember, his conclusion was that the landing site was considerably (20
Km?) north of the blue science ellipse (the 100x200 Km target), not near the
center as shown by the navigation team. The answers to FAQ on your webpages
mention that a scientist did this, but with no details and no comparison to
the navigation solution. The navigation answer to the landing site FAQ is
quite detailed but does not mention landmark analysis results. Have these
two (apparently conflicting) methods been compared on a map of Mars, to see
how well they agree?

ANSWER from Pieter Kallemeyn on July 28, 1997:
The final landing site was actually very close to the center of the blue
ellipse you're referring to.  We landed within 28 km (17 miles)
west-southwest from the center of the 200 x 100 km science requirement
ellipse.

The confusion stems from the fact that, at the conference you're referring
to, a difference ellipse was shown at a different scale, with the 'real
answer' being northwest of that ellipse.  The reason for that apparent
dispersion was because atmospheric flight errors and map coordinate errors
were not included in the ellipse calculation.  When one does all that
properly (which takes a lot of time to do) the ellipse and the 'truth' agree
much better.

Pieter Kallemeyn, MPF NAV