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Old 02-19-21, 05:54 PM   #61
Alpheratz
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Any CTDs with new sextant from v2.2.23?
No, I have no desktop crashes.
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Old 02-19-21, 06:00 PM   #62
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Originally Posted by Alpheratz View Post
No, I have no desktop crashes.
Great, same here!


Small hint...Not sure are you aware but when you move sextant up to measure altitude, press and hold LCtrl key for smoother movement...
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Old 02-19-21, 06:22 PM   #63
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Small hint...Not sure are you aware but when you move sextant up to measure altitude, press and hold LCtrl key for smoother movement...
Thanks! This hint is found at the end of my video "3 secrets of accurate celestial navigation in Silent Hunter 5". By the way, in the international TWoS, according to my observations, the use of the LCtrl key is less effective than in 2.0.9 RUS: when, after the Russian TWoS, I started testing the international TWoS, I thought that my LCtrl key was broken. And when I took measurements in 2.2.22 without the LCtrl key, at first I could not catch the star.
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Old 02-19-21, 06:40 PM   #64
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By the way, in the international TWoS, according to my observations, the use of the LCtrl key is less effective than in 2.0.9 RUS
Hm , I wish I know what have they changed in order to do that...
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Old 02-20-21, 06:55 AM   #65
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Hm , I wish I know what have they changed in order to do that...
I wanted to ask about this on the Russian-language forum, where TWoS 2.0.9 RUS was available for download, but www.silent-hunter.ru stopped functioning.
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Old 02-20-21, 07:55 AM   #66
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I have noticed that sometimes the NewSextant mod thinks a body is in a different spot than it appears to be. Typically for a noon latitude sight I don’t see UT show up after putting the object in. If I drop down a degree or so, sure enough, there it is. Now of course I don’t need time for a latitude sight, but it’s just odd. I have run into the same trying to shoot some stars, not very many, but sometimes I run into an issue where UT doesn’t show.

Regarding the sun, when I am doing a running fix for example, if I take, say, and afternoon sun line, for which I get UT displayed, when I use real almanac declination I get very close. However, when I use real declinations for a noon latitude sight (where UT doesn’t show up as mentioned before), I get very close using Alpheratz’s sun declinations. So there is definitely some disconnect perhaps in NewSextant. Not a big deal, because we can use “two sets of books”. But definitely something to investigate.

In short, if I can see UT show up in the display, I get very close using real declinations, but if UT doesn’t show, Alpheratz’s data seems to be closer. I have had a friend test this as well in parallel.
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Old 02-20-21, 09:13 AM   #67
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I have noticed that sometimes the NewSextant mod thinks a body is in a different spot than it appears to be. Typically for a noon latitude sight I don’t see UT show up after putting the object in. If I drop down a degree or so, sure enough, there it is. Now of course I don’t need time for a latitude sight, but it’s just odd. I have run into the same trying to shoot some stars, not very many, but sometimes I run into an issue where UT doesn’t show.
Are you talking about campaign or single missions?
I noticed the same but only in some single missions. In campaign, it seems that new sextant works normally. Tested in Black Pit campaign, mid Atlantic, and UT is shown up to ~60deg of altitude...
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Old 02-20-21, 09:44 AM   #68
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This is in campaign. And it’s really only at high noon, and maybe with some selected stars, but not very many. I should also point out this is on TWOS version .21. I am waiting for my campaign transition to upgrade to the latest. My friend is on .22 though with the same issue.
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Old 02-20-21, 10:11 AM   #69
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This is in campaign. And it’s really only at high noon, and maybe with some selected stars, but not very many. I should also point out this is on TWOS version .21. I am waiting for my campaign transition to upgrade to the latest. My friend is on .22 though with the same issue.

Ok, thank you for your report...


Any new strange things in the campaign which you previously didn't notice, without New Sextant?
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Old 02-20-21, 10:14 AM   #70
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Ok, thank you for your report...


Any new strange things in the campaign which you previously didn't notice, without New Sextant?
Not as yet, everything else seems to be very good. I appreciate your hard work on this. I try my best to spread the word about TWOS on Discord and elsewhere, because people still seem to be under the impression that SH5 should be abandoned as a mess.
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Old 02-20-21, 11:56 AM   #71
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I have noticed that sometimes the NewSextant mod thinks a body is in a different spot than it appears to be. Typically for a noon latitude sight I don’t see UT show up after putting the object in. If I drop down a degree or so, sure enough, there it is. Now of course I don’t need time for a latitude sight, but it’s just odd. I have run into the same trying to shoot some stars, not very many, but sometimes I run into an issue where UT doesn’t show.

Regarding the sun, when I am doing a running fix for example, if I take, say, and afternoon sun line, for which I get UT displayed, when I use real almanac declination I get very close. However, when I use real declinations for a noon latitude sight (where UT doesn’t show up as mentioned before), I get very close using Alpheratz’s sun declinations. So there is definitely some disconnect perhaps in NewSextant. Not a big deal, because we can use “two sets of books”. But definitely something to investigate.

In short, if I can see UT show up in the display, I get very close using real declinations, but if UT doesn’t show, Alpheratz’s data seems to be closer. I have had a friend test this as well in parallel.
Thank you, you have raised a very important issue. I know what's the matter here. This problem you are talking about is not a bug in the mod. The reason lies in celestial mechanics. There is only one possible calculation method for time correction, and this method is implemented in the New sextant mod:
There is a formula that describes the change in altitude within 10 seconds of time:

Delta h per 10 sec = 2.5 arc min * cos (Latitude) * sin (Azimuth)

The New sextant mod calculation algorithm calculates the altitude for a celestial body and compares it with the Measured altitude.

Delta h = |Calculated altitude - Measured altitude|

Time correction is performed based on the above two formulas.

Now about celestial mechanics. After the rise of a celestial body, it increases its altitude relatively quickly. The rate of increase in altitude decreases as you approach the upper culmination. Immediately before upper culmination, at the moment of upper culmination, and immediately after upper culmination, there is practically no change in altitude. After upper culmination, altitude decreases very slowly at first, then it happens faster, the rate of altitude decrease is maximum before the celestial body sets over the horizon. The most accurate time correction is possible when the Azimuth of the celestial body = 90 or 270: this corresponds to the largest altitude increment per unit time. The possibilities for time correction are almost exhausted when you observe the upper or lower culmination of a celestial body, when there are practically no changes in altitude (Azimuth = 0 or 180).

And now the most interesting thing is why UT disappears. Even if you follow all the recommendations for working with the sextant, which I talked about in my videos, you can achieve an accuracy in measuring altitude at the level of + -0.5 ... 1.0 arc minutes. The upper culmination moment corresponds to the maximum altitude that a celestial body can reach at a given latitude. When at the moment of upper culmination you measure Altitude with an error towards overestimation of the result, let it be at least the smallest error + 0.1 arc minutes, then for the New sextant mod calculation algorithm you get an altitude that a celestial body can never reach - based on the measured altitude, the time cannot be corrected, so UT does not appear.

Everything I talked about above concerns both the measurement of stars and the Sun.
Now, for the Sun alone. I have to manually correct over 2500 lines of the Sun.txt file in the New sextant mod in order for this mod to be usable for time-corrected measurements of the Sun. When taking measurements of the sun, you need to make sure that the SEXTANTSUNDIAMETER (String # 53 of "page layout.py") matches the size of the sun in the mod being used. For example, the new test build TWoS 2.2.23 should have SEXTANTSUNDIAMETER = 2.18666666667, but the Sun.txt file has not been redesigned yet, it is premature to talk about it. When measuring the Sun, when in the sextant interface field you enter the value "0" to indicate the celestial body being measured, the sextant "knows" that you are measuring the lower limb of the solar disk and the sextant reading is the altitude of the solar disc center, taking into account the influence of dip + refraction. that is, you don't need to add sun semidiameter to the measured value.

If you want to check the relevance of the declination of a celestial body (remember the maximum accuracy of a single measurement is + -0.5 ... 1.0 arc minutes, and in the case of measuring the Sun due to blurred contours of the solar disk, the error can be 2 - 3 arc minutes), regardless work of New sextant mod and time correction, then you should take measurements without entering the number of the celestial body in the sextant interface field. The sextant reading in this case will represent the actual altitude (without the influence of dip + refraction), which you can use directly to calculate declination when measuring the altitude of upper culmination at a latitude known to you. When checking the declination of the Sun, you should also not enter "0" in the sextant interface field. Add Sun semidiameter to the sextant readings (1 deg 5.6 arc minutes in new test build 2.2.23) and calculate the declination.
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Old 02-20-21, 12:37 PM   #72
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This makes sense. In the meantime, for noon latitude sights (where the problem is most pronounced) your declination numbers for the sun have yielded nearly spot-on results (as you mention, to compensate for the too-high altitude and thus too-low zenith distance). In game I normally get a morning twilight 3-star fix, and then a running fix during the day using a noon latitude sight advanced to another afternoon sun line (normally 3 hours later for a good azimuth change). For the afternoon sun line I always have UT displayed anyway so I can use actual declination (so no issues).

So it’s 2 sets of books for now and that’s OK.

I have also adjusted the diameter of the sun in the mod, mine corresponds to your value of just over a degree.

Thanks for posting that formula also. I will take a closer look at that.
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Old 02-20-21, 02:09 PM   #73
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For the afternoon sun line I always have UT displayed anyway so I can use actual declination (so no issues).

So it’s 2 sets of books for now and that’s OK.
You cannot rely on UT and draw conclusions on this basis (including regarding the correctness of declination) if you read UT when measuring the Sun, because there are 2 precisely established facts:
1. The declination of the Sun SH5 does not correspond to the actual declination of the Sun (you can check on your mod with the checkpoints on March 20, June 22, September 23, December 22).
2. The time correction is performed on the basis of the actual declination of the Sun (see file Sun.txt), and therefore gives a deliberately incorrect result.
The only exceptions are measurements taken around March 20 and September 23.
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Old 02-20-21, 02:20 PM   #74
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Originally Posted by Alpheratz View Post
You cannot rely on UT and draw conclusions on this basis (including regarding the correctness of declination) if you read UT when measuring the Sun, because there are 2 precisely established facts:
1. The declination of the Sun SH5 does not correspond to the actual declination of the Sun (you can check on your mod with the checkpoints on March 20, June 22, September 23, December 22).
2. The time correction is performed on the basis of the actual declination of the Sun (see file Sun.txt), and therefore gives a deliberately incorrect result.
The only exceptions are measurements taken around March 20 and September 23.
Aha I see, ok thanks. I was operating on the assumption that the time correction worked to offset even any declination errors such that using “real” almanac would yield correct results in any case where the corrected UT is displayed. In other words, I had assumed that the mod was trying to force real-world results through the time correction.

That said, my fixes are indeed not totally exact (allowing for possible measurement error), so I can understand what you are saying about the declination being fundamentally different than reality, which is unfortunate. But at least for the moment not wildly off, and still workable.
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Old 02-20-21, 02:30 PM   #75
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Also, if you need any help with fixing the sun data, I would be happy to assist. Any way to make this more like reality is a step in the right direction. Navigating in this game makes it so much deeper.
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