How to use TABLE 4- Sun's GHA and Declination for years 2001 to 2036

[CelNav57]

With a little effort you can get the Sun's GHA & Declination using TABLE 4. - GHA and Declination of the Sun for the Years 2001 to 2036- Argument “Orbit Time”. 

It's printed on one sheet of paper.


Our site also has The Nautical Almanac for the Sun only which has 15 days of the Sun's GHA and Declination on each page. Any year, printed on both sides, takes up about 14 pages.

The Nautical Almanac is necessary for the determination of GHA and declination of the various celestial bodies a navigator works with.

However, TABLE 4 is very difficult to understand and the explanation provided on the second page of the TABLE is confusing.

We wrote our explanation with the expressed purpose of making TABLE 4 easy to understand and use.  Of course, it does take some practice.


Hopefully, you'll find our explanation and examples useful.


How to use- TABLE 4- GHA and Declination of the Sun for the Years 2001 to 2036- Argument “Orbit Time”

[CarlosPindle]

Good work! You have made it very easy to understand.

I've stayed away from Table 4 for years. Sometimes I got the correct result but mostly not so.

Very much appreciate the explanation.

Carlos

[pabrides]

Pretty exhaustive workings, Celnav.  Congrats

However, neither your worksheet nor the description, as far as I have read it, explains what to do if your GMT of 17:20:14 was something like 17:38:14.  The original table description is quite clear on this point.

joe

[CarlosPindle]

Joe,

CelNav's explanation only uses the example time and date of January 22, 2017 GMT 17:20:14. It's easy enough to figure out any other date and time.

If the time had been 17:38:14 then the figures would be as follows (not showing "b");

c= 17:30= 77° 30'

d= 2° 04'

Total= 79° 34'

Carlos

[pabrides]

Joe,

CelNav's explanation only uses the example time and date of January 22, 2017 GMT 17:20:14.  It's easy enough to figure out any other date and time.

If the time had been 17:38:14 then the figures would be as follows (not showing "b");

c= 17:30= 77° 30'

d= 2° 04'

Total= 79° 34'

Carlos

Carlos, you may have missed a finer point...  The original instructions clearly state you use the closest whole hour to find OT...  So it would follow that if GMT is 17:38:00 one would use 18 hours + or - A table - not 17 (The Table 4 instructions use a similar example).  There may then be some difference in finding E if the OT date changes or to the B correction as per the Table example.

joe