Navigational stars in Silent Hunter 5

[derstosstrupp]

I like it a lot! So far so good on testing by the way, will continue tonight.

Updated Excel table for CelNav calculations (added a field for entering Sun semidiameter), for the convenience of testing NewSextant by the Sun.

https://drive.google.com/file/d/1l1J...ew?usp=sharing

[vdr1981]

Originally Posted by Alpheratz

Updated Excel table for CelNav calculations (added a field for entering Sun semidiameter), for the convenience of testing NewSextant by the Sun.

https://drive.google.com/file/d/1l1J...ew?usp=sharing

One question Alpheratz...As I said before, I'd like to add 30% smaller sun/moon then what you have now in the test update. Would that effect in any way your documentation? I mean, I don't want to create any unnecessary extra work for you. As far as I understand these stuff now, only sun/moon diameter had to be precised in the New Sextant scripts and we are good to go? Am I correct?


Here is a small mod to demonstrate smaller Sun and the Moon...https://www.mediafire.com/file/c4zuq...%2525.rar/file

Originally Posted by vdr1981

One question Alpheratz...As I said before, I'd like to add 30% smaller sun/moon then what you have now in the test update. Would that effect in any way your documentation? I mean, I don't want to create any unnecessary extra work for you. As far as I understand these stuff now, only sun/moon diameter had to be precised in the New Sextant scripts and we are good to go? Am I correct?


Here is a small mod to demonstrate smaller Sun and the Moon...https://www.mediafire.com/file/c4zuq...%2525.rar/file

Absolutely correct, will not affect the documentation, just fix SEXTANTSUNDIAMETER in Page layout.py

[vdr1981]

Originally Posted by Alpheratz

Absolutely correct, will not affect the documentation, just fix SEXTANTSUNDIAMETER in Page layout.py

Excellent! In that case please add new Sun and Moon to your test setup and tell me how it goes. I've calculated sun/moon diameter to be something like 1.74, but you should double check my calculations...

Originally Posted by vdr1981

Excellent! In that case please add new Sun and Moon to your test setup and tell me how it goes. I've calculated sun/moon diameter to be something like 1.74, but you should double check my calculations...

OK, Vecko, i was investigating the possibility of using the Moon for celesial navigation and came across inconsistencies that are hardly possible to eliminate. I compiled Moon Almanac 1939 - 1945 based on a real Moon and found out that there are differences from SH5 Moon. I find it extremely difficult to perform the same correction for the Moon, similar to the one I did for the Sun, due to the complex pattern of the Moon's motion. For this reason, I did not include Moon Almanac in the documentation and did not raise this issue in my videos.

[vdr1981]

Originally Posted by Alpheratz

Vecko, please tell me where can I get the new sun and moon?

https://www.mediafire.com/file/c4zuq...%2525.rar/file

By the way, I was investigating the possibility of using the Moon for celesial navigation and came across inconsistencies that are hardly possible to eliminate. I compiled Moon Almanac 1939 - 1945 based on a real Moon and found out that there are differences from SH5 Moon. I find it extremely difficult to perform the same correction for the Moon, similar to the one I did for the Sun, due to the complex pattern of the Moon's motion. For this reason, I did not include Moon Almanac in the documentation and did not raise this issue in my videos.

That's really shame , but quite expected at the same time...
Anyway, being able to navigate with Sun and at least few stars is still really awesome and unprecedented.

[vdr1981]

And here is the new test update No 7 which includes all previously mentioned tweaks, updated documentation, samller sun/moon, set sun/moon diameter in scripts ect...

Note that in this version, New Sextant will become available in your JSGME only after you enable the main Real navigation mod in order to avoid some badly arranged mod lists...

Also , compatibility with other conflicting mods (auto ship recognition and campaign advance verifier) is now fixed so enabling order is not important anymore... The mods will automatically "make them self compatible" as you enable them one by one in your JSGME...

https://www.mediafire.com/file/fb6av...Test7.rar/file

The new Sun and Moon have the following dimensions:

SEXTANTSUNDIAMETER=1.61555555555
SEXTANTMOONDIAMETER=1.5125

I was lucky to find NewSextant mod. I found it almost immediately after it was published, but I was not immediately able to appreciate its merits and the reason why it was made that way. Now, after years of researching celestial navigation in Silent Hunter 5, this mod seems to be the most thoughtful and graceful, the "golden key" that finally opens up Celestial Navigation for us in Silent Hunter, we have all been waiting for it.

I was especially pleased with the fact that this mod turned out to be so flexible that it became possible to introduce into it my developments regarding the correction of celestial coordinates.

Thanks to Vecko and derstosstrupp for working on this as a team.

[derstosstrupp]

Originally Posted by Alpheratz

The new Sun and Moon have the following dimensions:

SEXTANTSUNDIAMETER=1.61555555555
SEXTANTMOONDIAMETER=1.5125

I was lucky to find NewSextant mod. I found it almost immediately after it was published, but I was not immediately able to appreciate its merits and the reason why it was made that way. Now, after years of researching celestial navigation in Silent Hunter 5, this mod seems to be the most thoughtful and graceful, the "golden key" that finally opens up Celestial Navigation for us in Silent Hunter, we have all been waiting for it.

Thanks for those figures. Yes I agree, I couldn’t be happier. For years I waited for a platform to be able to do this in a simulation, and finally it’s possible.

[vdr1981]

Originally Posted by Alpheratz

The new Sun and Moon have the following dimensions:

SEXTANTSUNDIAMETER=1.61555555555
SEXTANTMOONDIAMETER=1.5125

Maybe I created some mistake in my calculations or it's simply measurement error?

These are two pictures which I used and I got ~ 1.74 value for Sun (zoomed in to check my measurement)...





Is my calculation OK? Did I measure upper and lower limb incorrectly?

No, the error is not in the calculations, but in the measurement technique. All measurements are recommended to be carried out using the Fine aiming line, which is activated by pressing this button.



When measuring, it is necessary to capture the extreme row of pixels of the lower and upper extremities of the solar disk.



In addition, measurements of the diameter of the Sun should be carried out on a pause. Otherwise, between the first and second measurements, the sun can change its altitude by a certain amount, the profile of the solar disk (outlines, set of pixels) also changes by crosshair movement - this is purely "computer reason" introduces an additional error of measurement. You can check your measurement method yourself: take 5 measurements - if the variation is more than 0.3 arc minutes, then the quality of the measurements is poor.

In my series of 10 Sun measurements, the variation (difference between Max and Min result) was 0.2 arc minutes. 1.61666666 and 1.61333333. I took the average of 10 measurements as the result.

[vdr1981]

Originally Posted by Alpheratz

No, the error is not in the calculations, but in the measurement technique. All measurements are recommended to be carried out using the Fine aiming line, which is activated by pressing this button.

Thanks for clarification...


But, there is one problem (I think). I've always suspected that measuring by stadimeter button (AKA fine aiming line) is introducing certain degree of error depending on how much stadimeter is moved up. That's why avoided to use it in my measurements...


Later I'll post few screenshots to demonstrate this "error". It could be that imprecision in aspect ratio fixes are effecting sextant function both from normal periscope/UZO and from sextant as well.


In his video, YS is also avoiding to measure altitude by using stadimeter button...I wonder, is it because of this reason...

Originally Posted by vdr1981

Thanks for clarification...


But, there is one problem (I think). I've always suspected that measuring by stadimeter button (AKA fine aiming line) is introducing certain degree of error depending on how much stadimeter is moved up. That's why avoided to use it in my measurements...


Later I'll post few screenshots to demonstrate this "error". It could be that imprecision in aspect ratio fixes are effecting sextant function both from normal periscope/UZO and from sextant as well.

I am aware of this problem. Take measurements so that you don't have to raise the fine aiming line above 1.5 - 2 centimeters from the crosshair, then there will be no error.

At one time, I investigated in great detail all the reasons causing errors in measurements, this is how my video "3 secrets ..." was born, where I summarized my many years of experience in 5 minutes.

[vdr1981]

Originally Posted by Alpheratz

I am aware of this problem. Take measurements so that you don't have to raise the fine aiming line above 1.5 - 2 centimeters from the crosshair, then there will be no error.

At one time, I investigated in great detail all the reasons causing errors in measurements, this is how my video "3 secrets ..." was born, where I summarized my many years of experience in 5 minutes.

I experimented a bit with cameras.cam values but I couldn't find any parameter which has any effect on this error... There must be something in the files which effects stadimeter behavior, I just hope it isn't hard codded. We may have problems in situations near the equator when the Sun is high, like 80+ deg, but again, with some resourcefulness and little bit of math, the error can be ruled out during the calculations...