Lunars: Why to remove the Longitude input/output "calcs" #253
Description
Hi All, I decided to make a new Issue dealing specifically with whether or not to have CelNav Lunar module calculate a revised longitude (see #239 where Bob wants it and thinks everyone gets what they want, and I question its value and accuracy and that it needlessly clutrers the screen with no benefit or real output ).
I've thought about this, went over the two papers that we've mentioned (Brunner and Burch) and looked at how CelNav Lunar is calculating a revised Longitude.
I figured out how CelNav calculates it: it takes the UTC change (that Bob's method computes and we've agreed on) and simply converts that UTC change to Lon Error (') (see the following screen shot). In other words it is not independently calculating a longitude--it is only taking our lunar distance UTC change, converting that to a longitude correction, and then adds that longitudinal correction to the longitude we had (randomly) inputted in the Find box.
Sure, the time correction to longitude correction is correct. But that gives us nothing! It is not calculating a longitude, it is only calculating a longitude correction (a very simple calc). In other words it is not doing a longitude calc.
Lets take two examples: in one I input a longitude in the Find box of 92°13'W, and then I input a different longitude in the Find box of 150° W (see attached screen capture) (the same LD and time) and presto...the calculated longitude is completely different. Duh!... In other words, this is not a real longitude calculation!
Again, this is why we should remove the longitude inputs/outputs, unless we use a completely different method.