Re: Positional requirements

Jim Varney (
Mon, 27 May 1996 10:44:37 -0700

Robert McNaught wrote:

>>Also in theory, an orbit can be deduced from two positional
>>observations at two different times.  This method generates two
>>possible orbits that pass through the two points.  One of the two
>>orbits is obviously "wrong" and is discarded.
>Actually, there are an infinite number of orbits that pass thru two

My error :(

In the two-position and time-of-flight problem, I overlooked that the
position vectors are just that, vectors.  Obviously the distance or
length component is unknown when making an alt/az or RA/dec observation.

Don't we all have radars in our back yards?  :)

 -- Jim

Jim Varney      |  121^ 23' 54" W,  38^ 27' 28" N   |           Sacramento, CA
Member, SeeSat-L|            Elev. 31 ft.           |