Celestial Navigation Plugin Redux

[rgleason]

We finally after a half dozen tries, including making a new Sight, I was able to get the Arcturus value of 79.501993 to accept without an error. In fact one try I ended up with a bunch of zeros and gibbberish in the field.

This value ends up being degrees 79 minutes 30.12 and it shows as Measurement 79.5020 in the Sights List. Both the old sight and the new sight worked eventually.
This needs more study and a solution.

The problem I think was that there were additional spaces or characters in the field that are not seen! - I do not know if there is some way of range checking and removal of miscl characters, so that what is entered can be used properly.

After getting it Arcturus working, the FIX error is 23nm and turning off the SUN it becomes 7.3nm.

[rgleason]

Stelian, good point. Actually, shouldn't we be able to put in a UTC Offset, for example, Boston is UTC-5 and then we could use local time?
What is it using now? Local Computer time and the UTC offset stored in the computer for the time zone?

I don't know if the manual has any of this, since I wrote it with the help of others I should know....
"For celestial navigation work all observations are recorded in time and date based on Greenwich, England. GMT is also known as “UT”. "

Okay, my computer has 6:10pm
I make a NEW Sight and look at TIME
Date: 10/10/17 Hours 22, Minutes 10, Secs 04
Ok it is coming straight from the computer. I have set time and time zone automatically ON. So the time will always be changing as the computer does. Maybe we should have something specific about this in the manual. In practice, the sightings will have specific times to be recorded anyway and they will be behind the computer, so I don't know what the advantage of having the computer clock set the TIME is. --Do you understand this?

Yes, I agree with this, good idea!

But maybe we could add a button in the main dialog for "Duplicate" a sight. This would allow to copy every parameter, including the time.

I'll look into the Dirty Field Entry problem for Measurements of Altitude and Azimuth.

[rgleason]

I've been working for 1/2 an hour on getting an Alkaid working after it stopped with Measurement too small. II've gone through all the fields, deleting and typing in fresh values that are identical. I does have the same measurement value for altitude that the other one that is working has. I've tried changing stars and going back and resetting the measurement, etc.

What is weird is the Fix X changes slightly when I toggle it on and off, but the sight circle does not show, but it is being used to calculate something!.

I am going to delete the one that works and see if the one that doesnt work starts working.

Got it now. The message "Measurement is certainly likely too small. sight may not appear." Means you have the "Minutes of Uncertainty" set to Zero and the line of sight isn't going to appear." you dumb ....[3 or 4 letter work]

Maybe there is a better way to handle this, Like a prompt When hit "Done" from "Find" or better yet, don't let the user leave modifying that field without it being at least ""1". If Minute of Uncertainly is set to 0- "Minutes of Uncertainty are set to Zero, please please change it to a positive number ____"

What I was doing was clearing fields, and I had cleared that one and set it to Zero, maybe it should automatically be set to "1" when you leave the field and it is set to 0?

[rgleason]

I'd like to ask if there is a reason that the "FIND" function always takes Long and Lat from the Boat? Couldn't we have an alternative
Checkbox: "Set Long & Lat separately from the Boat Position."

Would make things easier in this situation.

[rgleason]

Attached are the sight.xml.doc (remove the doc please) which is the file for the exercise below, in case someone wants to see what I was doing.

You can rename your sights.xml file for reuse later, and load this one....

In fact, that would be a wonderful improvement to Cel_Nav, to be able to Save, Save as, and Load sight.xml files from the User files
for Windows this file is C:\ProgramData\opencpn\plugins\celestial_navigatio n

[rgleason]

Have corrected the text errors in the Cel_Nav_pi wiki pages Under "Test: Armchair..."
one image may be wrong. Also added sight.xml.doc. Thank you Stelian for finding those errors and all your help!!

Improvements for Consideration
1. Time Tab - Note: Enter UTC. Time is normally from computer time and time zone.
2. Time Tab - [Checkbox Set] default time (UTC).
3. Sight > Minutes Uncertainty - If zero force it to 1 minimum
4. Sight > Find[Checkbox] Set Long & Lat separately from Boat Position.
5. Sight.xml - Save, Save as and Load sight.xml files from the User files. For for Windows this file is C:\ProgramData\opencpn\plugins\celestial_navigatio n.
6. Ability to Print the Calculations and sight tables.

Thanks

[stelian]

Originally Posted by rgleason

Got it now. The message "Measurement is certainly likely too small. sight may not appear." Means you have the "Minutes of Uncertainty" set to Zero and the line of sight isn't going to appear." you dumb ....[3 or 4 letter work]

Maybe there is a better way to handle this, Like a prompt When hit "Done" from "Find" or better yet, don't let the user leave modifying that field without it being at least ""1". If Minute of Uncertainly is set to 0- "Minutes of Uncertainty are set to Zero, please please change it to a positive number ____"

What I was doing was clearing fields, and I had cleared that one and set it to Zero, maybe it should automatically be set to "1" when you leave the field and it is set to 0?

It's not so simple, because the value can be smaller than 1 (like 0.001 minutes) and still be valid... And I believe that the valid values depend also on the level of zoom...

We could gray out the "OK" button if the value is not positive, but this would not give much feedback to the user, and won't prevent the "Measure is too small" message depending on the value entered.

[stelian]

Originally Posted by rgleason

In practice, the sightings will have specific times to be recorded anyway and they will be behind the computer, so I don't know what the advantage of having the computer clock set the TIME is. --Do you understand this?

I think that in practice, you will use OpenCPN on a boat just after having used your sextant. So you enter a new sighting, and you want to set the date to the date of your measurement, which is normally just a few minutes before. So choosing the current date/time seems a good choice to me.

Besides, if it weren't choosing the current date/time, what would you like the plugin to choose ? The date/time of the previous sighting ? Epoch ? I'm not sure there is a better choice than the one actually implemented.

[stelian]

Originally Posted by rgleason

Yes, I agree with this, good idea!

I've implemented the "Duplicate" button in my fork on github, please check.

[stelian]

Originally Posted by stelian

I've implemented the "Duplicate" button in my fork on github, please check.

If others want to test: http://popies.net/tmp/celestial_navi...1sp4-win32.exe

[P_Dub]

The final result I got is close to the Boston marina:-
Lat:- 42⁰21.0`N
Long:- 71⁰02.9`W
Is this the same as what you did obtain?
If so all you need to do is make a better interface, if possible.

[rgleason]

I realized the list was missing Stelian's duplicate sight this morning, so I revised the list. Please make any comments/improvements you see are needed in github Issue #21 or the CF thread.

Thanks for the duplicate sight Stelian.

Attached is this morning's sight.xml.doc (Why is the sun off so much? 2 Sun sights one altitude, one azimuth. Several others are off too, one because it is low on horizon I think. By eliminating the outliers I get 1nm off.)

Improvements for Consideration (Revised+Added)

1. Time Tab - Need a Note: Enter UTC. (Time is normally from computer time and time zone. )
2. Time Tab - [Checkbox-global] Set default time to a fixed (UTC) for all sights.
3. Clock Offset - Clock Correction - Initialize it to "0" on the first time the plugin is loaded. Not -10,000!
4. Sight > Minutes Uncertainty - If "0" force it to "1" minute minimum. Then is message needed?
5. Sight > Find - [Checkbox-global] Set fixed Long & Lat independently from Boat Position.
6. Ability to right click - "Move Boat to Lat\Long" or ability to enter DR Position and have that used (see note at bottom).
7. Sight.xml - Save, Save as and Load sight.xml files from the User files. For for Windows this file is
   C:\ProgramData\opencpn\plugins\celestial_navigatio n.
8. Single Sight - Ability to save, save-as & load a single "sight" in XML format.
9. Fix - Current calcs use a "least squares" which results in a visual Red" X" for fix. It would be very nice to have fix Lat Long appear somewhere where it could be copied with cursor.
10. Calculation Tab for a sight -Include the observation time & date and details. Azimuth calcs are blank.
11. Ability to print the calculations and a detailed Site Table with.
12. Overview Button "An overview giving the fix position and the fix accuracy figure together with the observation and reduction data and maybe some intermittent calculation values would be a plus (all data for a single fix in one Overview." Ability to copy to clipboard, print, save, etc.
13. Ability to duplicate a sight. (Stelian has just done this one!)
    Include the observation time (GMT or UT) under the Computation Tab for saving. E

Note: Entry of DR position prior to Fix Entries as an assist. (Have a space on the interface for entering the DR position prior to entries. Otherwise you may have a result in the Northern hemisphere instead of the Southern and vice-versa. This is undesirable and definitely inappropriate.)

Thanks

This file is from C:\ProgramData\opencpn\plugins\celestial_navigatio n
Rename your file and take the "Rick2.doc" off of this one and place it in this directory to see my sights and fix. Then reestablish your original sights by re-naming the files again. This is why I'd like the ability to save, save as and load these files.

[rgleason]

Stelian, P_Dub here is a screenshot of a better Fix with just 4 sights used.
It is off by about .5 nm Fix is Lat 42.21 Long 71deg 6.1min

I don't understand what the "Least Squares Fix calculation" two "Initial" boxes are for, Nor do I understand the algor"Spheres" "Cones" "Plane" etc.
They don't seem to change the FIX too much. Anyone understand this?

Should be near Copley Sq.

[P_Dub]

For the sights that are too low, it is definitely not useable in practice. Generally it is difficult to obtain a good sextant result with that. As for the high altitude say above 80d it becomes difficult to set at the vertical and generally are discarded. Although someone can still use them but you need a good experience for that.
Regards.

[rgleason]

Note. Before you install Stelian's plugin, copy your sights.xml!! to sights-name.xml so it is not overwritten.
This is also why we need save,save as & load *.xml sight files.
Would also be good to save daily sights taken with sight-date format.xml so they are all available.

Norton is squashing my download. Easier to git fetch pull your repos I guess.

LATER: I guess the plugin will not overwrite your sights. That is good, but still could use save,saveas & load.