Re: [find_orb] Re: Make Ephemeris settings

Bill J Gray Apr 23, 2012

Hi Tomas, Peter,

pbirtwhistle wrote:
> However, the logic seems to be to start the first ephemeris
> position with the NEXT ephemeris interval, so for instance,
> generating an hourly ephemeris using +0 at the moment I'm
> typing this (at 14:39 UT) would generate an ephemeris
> starting with 15:00 UT.

True. You _can_ have the starting time be -1h to have it
start at the preceding step. (You have a lot of flexibility
in how times are entered, as described at

http://www.projectpluto.com/update8d.htm#time_entry

In general, one is best off with something unambiguous,
such as a four-digit year and three-letter month. But the
ability to say things like "start the ephemeris three days
before that" or "six hours from now" can be quite useful.)

As you mention, one can type in the MPC code in the 'lat'
field. This is handy, if you know about it... but I should
probably have the controls look something like

Observer location:

(o) MPC code [J95]
( ) Latitude [ ]
Longitude [ ]

...i.e., you select a radio button to determine whether the
MPC code or the lat/lon is used, with separate boxes in which to
enter those quantities. I'll do that. It doesn't help much to
have "nifty" features if people can't actually see them.

-- Bill