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SUBSIM: The Web's #1 resource for all submarine & naval simulations since 1997 |
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#5236 | |
Grey Wolf
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I think that the measurement is connected with the sun (at midday?). If we check the range between sun and horizon we can calculate the current ship's latitude from tables. (so the "0" should be located at horizon line). The question: we have our current ship's position on map - should we extra check the lattitude or longitude? ![]()
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#5237 | |
Black Magic
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EDIT: from reading the wikipedia on the Sextant it appears I need to be able to rotate the Sextant so horizontal measurements can be taken also. Have to add now. Last edited by TheDarkWraith; 12-08-10 at 12:21 PM. |
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#5238 | |
Grey Wolf
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![]() Lol... I think that I know how to check a longitude (sorry I'm not sure - I'm no seamen): You have tables with moon/sun rises/sets at GMT - different value with table and GMT shows you where you are: Sun rises at 7.00 GMT, in "real" at 8.00 - you are at 15°W, between Portugal and Azores. How does it implement... no idea...
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#5239 |
Black Magic
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letting you use the sextant in the horizontal plane turned out more difficult than I thought
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#5240 |
Lieutenant
![]() Join Date: Nov 2006
Location: St. Petersburg, Russia
Posts: 264
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Wikipedia says that an experienced navigator can make out position with an accuracy up to 460m and that normaly even during hazy days error is not more than several NM.
Ideally to fully simulate a sextant we would need a stadimeter with one picture always holding sun in the view and the other moving up and down with the mouse wheel so the horizon could be brought into view and the lower limb of the sun would be made to touch horizont. Then, providing you were also seeing degrees of the pictures' offset angle and the old good chrono on the screen, you could make out your lat and long simultaneously at noon, as a real navigator would do, hence fully simulating the sighting and navigation calculations (that are quite simple in fact) using a sextant. And for 100% simulation we would need to see the degrees in an inset depicting sextant's index arch. But that is asking too much I guess the simple 'sextant' band from SH3 although not as convinient and precise still does the job. There is one fundamental thing, however, to say that sextant is functional we need to prove that sun altitude is actually reflecting lat and long in the game. ![]() That was about sextant. To have full real navigation we also need dead reckoning simulated, i.e. navigator should continuosly draw and calculate the boat's track based solely on course and speed as he does already but with some error to simulate currents, approximations and non-precise instruments (especialy knots indication). Then it would be possible to intersect dead reckoning with sextant's fix and find your position. But that would require correcting the last line of the dead-reckoning path to fit the fix. Which I recon is impossible to do in SH. |
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#5241 | |
Black Magic
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![]() ![]() I can add dead-reckoning to the game. I made a tremendous breakthrough while working on this part of the mod that let's me do things like my super marks idea and dead-reckoning ![]() The feedback I'm getting from most is that they don't want dead-reckoning. They want to be the one putting the plots on the map (they want to be Captain and Navigator at same time). |
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#5242 | |
Lieutenant
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Great news about the dead-reckoning! As if I had any doubts that you are genius... ![]() |
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#5243 | |
Grey Wolf
![]() Join Date: Feb 2009
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![]() To measure the lattitude check the range of sun (probably at midday?) over horizon line. If you check it you can calculate the current ship's latitude from tables (different sun max height for day and month). http://damecarcass.blogspot.com/2009...l-horizon.html You can do that with two measures: 1) when sun rises (to check the longitude) 2) max height of sun (to check the latitude)
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#5244 |
Lieutenant
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Location: St. Petersburg, Russia
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The band itself is very easy to check - very quick and rough check is to check the height of the Polar star in degrees over the horizont that is the angle between the star and the horizon (not the bottom of the screen). And that will give you your latitude (providing you are in northen hemisphere where the star is visible). For example - if the star height is 30, then you are on the 30 latitude. Compare it to the actual posit.
To check the longitude you need to set your position exactly at Greenwich meredian, i.e. long = 0. Then the sun should stop rising (use band to check sun height) exactly at 12:00PM and after it should start to descent. If your posit is 15 degrees westerly - then the sun will be at its zenith at 1:00PM, i.e. every 15 degrees to the W give you +1 hour to the noon time as compared to GMT. 1 degree W gives +4 min. We must also check if the sun's position corresponds to lat. It is slightly more difficult. I'll explain later. |
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#5245 | |
Black Magic
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![]() Being that SH5 is based off of SH4 which is based off of SH3 and what you are talking about above is correct in SH3 then it should work in SH5. |
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#5246 | |
Lieutenant
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Location: St. Petersburg, Russia
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#5247 |
Seasoned Skipper
![]() Join Date: Aug 2010
Location: 49°44´N 129°40´E
Posts: 665
Downloads: 124
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Report:
As I understand it now map centered in coordinates, the latter which gave the navigator after the start of the game or the latest calculations of the position. Now it is impossible to guess the real position of the boat ![]() ![]() ![]() It now remains to check the sextant. Sun table - just what need. ![]() @Vanilla Excellent comments on navigation. I, too little competence in matters of navigation. Thank you for your help.
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Speed squadron is the speed of the slowest ship ... but only so long as on the trail of the squadron did not sit submarines ... ![]() Last edited by Obelix; 12-08-10 at 08:38 PM. |
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#5248 |
Seasoned Skipper
![]() Join Date: Aug 2010
Location: 49°44´N 129°40´E
Posts: 665
Downloads: 124
Uploads: 7
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Last update rus for 5.4.0
http://www.subsim.com/radioroom/down...o=file&id=2897
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Speed squadron is the speed of the slowest ship ... but only so long as on the trail of the squadron did not sit submarines ... ![]() |
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#5249 |
Black Magic
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got a PM from sober asking if it was possible to choose your starting location for the historical missions. Before I had discovered the breakthrough when working on the real navigation it was not possible. But since discovering that breakthrough I've been able to make this happen (and discover another important breakthrough
![]() when you click 'Change' a HUGE world map will become visible. It starts out allowing you to pan it with the mouse. It acts just like all draggable items (left click and hold and drag). When you have the world map in the general vicinity of where you want to start you press the 'Tab' key. This takes the world map out of pan mode and into click mode. Now whereever you click on the map will be your new starting location ![]() In order for the change to persist you have to click 'Apply changes' as usual. Start the game and you'll find yourself in a new location ![]() |
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#5250 |
Ace of the deep .
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Absolutely fantastic
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dbrn, favorite, new ui |
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