Celestial Navigation Plugin Redux

[seandepagnier]

NAV,

Does the WMM plugin report the correct declination? Did you copy the IGRF11.COF file from git into the data directory? If it is missing, the plugin normally displays a warning message.

Could someone else please verify NAV's result?

[rgleason]

I have entered in 52.5 and 4.5 into the find dialog, and with check and uncheck magnetic box I get a difference of 0.4 degrees.

Sean I've done the same.
With Magnetic Unchecked Sun Azimuth is 66.291688
With Magnetic checked Sun Azimuth shows 80.61352
I do have IGRF11.COF file dated 6/9/2013 130kb similiar to that from git, in the C:\Program Files (x86)\OpenCPN\plugins\celestial_navigation\data directory.

--Maybe it is working for Linux but not completely for Windows?

Darn IMAGES PNG are not working for me either. I cleaned out the Browser CACHE too!

Sean, I like the pic of your boat.

[NAV]

Originally Posted by boat_alexandra

NAV,
Does the WMM plugin report the correct declination?

Yes, WMM reports +0.4 degrees variation.

[rgleason]

Sean,
With WMM enabled, I get .4 at Position at 52.5N 4.5E

With WMM still enabled, and with the file in celestial_navigation/data/IGRF11.COF
In Cel_Nav using "Sun" and "Find" entering position at 52.5N 4.5E

With Magnetic unchecked
Azimuth 283.249778
Altitude -19.126199

With Magnetic checked
Azimuth 297.569442
Altitude -19.126199

Hope this helps

[rgleason]

NAV at what stage is your review of Celestial Navigation?
I hope it is working as a user might expect and is clear in nomenclature now.

I believe Sean has tried to be responsive to your valuable review and we hope the plugin is now ok!

Also thankyou for your help as an experienced celestial navigator. Much appreciated.

Sent from my SCH-I545 using Cruisers Sailing Forum mobile app

[NAV]

Originally Posted by rgleason

NAV at what stage is your review of Celestial Navigation?

Haven't done much lately. Today I downloaded version 1.8 (released 2014-06-29). Now I will first look into the Dutch translation.

However, one observation already: I still see the 14 degrees difference between magnetic and true azimuths near the coast of The Netherlands.

[seandepagnier]

NAV,

If you pull the latest version from git, I think the azimuth problem is fixed.

It seems to crash on exit on my wine setup but I cannot debug this. Anyone else see it?

[NAV]

Originally Posted by boat_alexandra

NAV,

If you pull the latest version from git, ....

Rick,
Can you build a windows version for me please?

[rgleason]

Celestial Navigation v1.8 shows:

Celestial Nav after 3 fixes (old from before) shows:
Latitude: -70 -32.3'
Longitude: 5 57.8'
Error: 0.0233

In Opencpn 3.2.2 when hover over the dark read crossed lines from the fixes.
70.34.2591 south (these numbers change a bit with minute cursor movement)
5.58.4014 east (these numbers change a bit with minute cursor movement)

WMM shows with Cursor over red crossed lines
Incl -61.1 deg
Var -24.1 deg (24deg8'w)
----------
With Celestial Navigation v 1.9
Celestial Nav after 3 fixes (old from before) shows:
Latitude: -70 -32.3'
Longitude: 5 57.8'
Error: 0.0233

In Opencpn 3.2.2 when hover over the dark read crossed lines from the fixes.
70.33.7702 south (these numbers change a bit with minute cursor movement)
5.57.8858 east (these numbers change a bit with minute cursor movement)

WMM shows with Cursor over red crossed lines
Incl -61.1 deg
Var -24.1 deg (24deg7'w)

===========

Sean and NAV

It now recompiled and updated on Opencpn Beta File Thingie.
Opencpn Beta File Thingie rguser rgpass
look in 3.2.2 PI WIN directory

Sean just one warning...
Build succeeded.

"C:\Data-Dart\Up-Soft\Navigation\o-plugin\celestial_navigation_pi\build\ALL_BUILD.vcx proj" (default target) (1) ->
"C:\Data-Dart\Up-Soft\Navigation\o-plugin\celestial_navigation_pi\build\celestial_nav igation_pi.vcxproj"
(default target) (3) -> (ClCompile target) ->
..\src\CelestialNavigationDialog.cpp(163): warning C4800: 'int' : forcing value to bool 'true' or 'false' (performance warning) [C:\Data-Dart\Up-Soft\Navigation\o-plugin\celestial_navigation_pi\build\celestial_nav igation_pi.vcxproj]

1 Warning(s)
0 Error(s)

CPack: - package: C:/Data-Dart/Up-Soft/Navigation/o-plugin/celestial_navigation_pi/build/
celestial_navigation_pi-1.9-win32.exe generated

[NAV]

Originally Posted by boat_alexandra

If you pull the latest version from git, I think the azimuth problem is fixed.

To me too, this problem seems to be solved in beta version 1.9.

[NAV]

Star observations
A calculation in one of my textbooks using 4 star sights gives the following position: 06 09'.7 N 090 30'.2 E

Using the same input data, the plugin calculates 06 12'.1 N 090 47'.9 E. That's a very large difference, even taking into account that there is a difference of 13 minutes between the first and the last star observation (in the textbook the LOP's are moved accordingly; the plugin can't handle this).

The textbook can be wrong too, although that's unlikely.

Bug
Double clicking in the main window on one of the entered observations, shows the data of another observation than was clicked on.

[seandepagnier]

Originally Posted by NAV

Star observations
A calculation in one of my textbooks using 4 star sights gives the following position: 06 09'.7 N 090 30'.2 E

Using the same input data, the plugin calculates 06 12'.1 N 090 47'.9 E. That's a very large difference, even taking into account that there is a difference of 13 minutes between the first and the last star observation (in the textbook the LOP's are moved accordingly; the plugin can't handle this).

Why do you say it can't handle this? It can have a different time for every observation.

The textbook can be wrong too, although that's unlikely.

Maybe we can compare the numbers in the calculations tab to the textbook?

Bug
Double clicking in the main window on one of the entered observations, shows the data of another observation than was clicked on.

Can you produce this with only 2 sights? How exactly?

[NAV]

Originally Posted by boat_alexandra

Why do you say it can't handle this? It can have a different time for every observation.

Each observation has it's own observation time, but which time is used for the fix? In case the star observations span 15 or 20 minutes and the vessel speed is relatively high, the LOP's (when using the old fashioned computational methods) should be shifted to one time, according to speed and course of the vessel. How does the plugin handle this?
Traditionally (because it's so easily done), a noon position is obtained from a sun sight at 12:00 LT an a (shifted) sight at about 09:00 LT. As I understand so far, this is not possible using the plugin.

This leads me to the question: can I obtain somehow a textual description of the computational methods that you use in the plugin?

Originally Posted by boat_alexandra

Maybe we can compare the numbers in the calculations tab to the textbook?

Will follow later ...

Originally Posted by boat_alexandra

Can you produce this with only 2 sights? How exactly?

Yes, same problem. Entering two sights, double clicking on one of them in the main window (or selecting one and clicking on the 'Edit' button) shows the other sight and vice versa.

[NAV]

In case an error is made entering the sight data, corrections cannot be made. Any corrections for a sight made via the 'Edit' button are not being saved.

[NAV]

Attached is the test data for the 4-star fix.