NavList:

Hi Andres,

 

This data came from the United States Coast Guard Question pool.  All given information is as it is written in the pool and the 0.1nm error in declination should not effect the plot enough to give the correct answer given the scale of the plotting sheets available (either universal or the larger scale PS 923 I think it is, but I can't remember the exact number).

 

Jeremy

 

Jeremy,

The declination you has given, has 0.1' of error, see my calculations and the USNO data http://aa.usno.navy.mil/data/docs/celnavtable.php

¿This data came from the 1981 NA?

For manual calculation of the fix, a plotting sheet or also a great scale nautical chart is used if available.

Andrés


-----Mensaje original-----
De: NavList@fer3.com [mailto:NavList@fer3.com] En nombre de Anabasis
Enviado el: miércoles, 16 de julio de 2008 18:35
Para: NavList
Asunto: [NavList 5863] Exercise #16 High Altitude Sights near Noon


Exercise 16  Position near Noon by High Altitude Sight

As promised, I am posting a couple of Celestial Navigation problems
that were presented to me on my Last US Coast Guard Examination.  I am
quoting them verbatim and will give a list of reference materials
available in the exam if people wish to replicate my exam conditions.
Reference materials:  1981 Almanac, Bowditch Vol 2- 1981 edition, HO
229 Vol 2, Plotting sheets, plotting tools, non-navigational
calculator, writing instrument.

Here is the problem and multiple choice options:
"On 13 November 1981, your 1030 ZT DR position is Lat 19 deg 03'S,
Long 6 deg 34'E.  You are on course 164 deg T, speed 12 knots.  You
take the following observations of the Sun:
Zone Time    GHA        Declination    Observed Altitude (Ho)
1112        351 deg 55.4'    S 18 deg 00.4'    88 deg 08.0'
1121        354 deg 10.4'    S 18 deg 00.5    88 deg 33.9'

What is the 1200 position?"

A)    Lat 19 deg 22.3'S, Long 6 deg 37.8'E
B)    Lat 19 deg 20.1'S, Long 6 deg 41.4'E
C)    Lat 19 deg 17.6'S, Long 6 deg 39.2'E
D)    Lat 19 deg 15.8'S, Long 6 deg 36.8'E

As a note, the answer MUST be one of the multiple choice options.  If
your fix does not match the choices, you must choose the one you think
is most correct.  As you can see, this is mostly a plotting exercise.
I suggest using the largest scale plotting sheet you can muster.

Jeremy

U.S. Naval Observatory
Astronomical Applications Department

Celestial Navigation Data

Celestial Navigation Data for 1981 Nov 13 at 11:12:00 UT For Assumed Position: Latitude S 19 03.0 Longitude E 6 34.0 Almanac Data | Altitude Corrections Object GHA Dec Hc Zn | Refr SD PA Sum o ' o ' o ' o | ' ' ' ' SUN 351 55.4 S18 00.3 +88 13.7 54.1 | 0.0 16.2 0.0 16.1 VENUS 301 28.7 S26 40.2 +41 50.4 109.2 | -1.1 0.2 0.2 -0.7 MARS 55 13.1 N 8 09.5 +23 19.9 288.2 | -2.3 0.0 0.1 -2.2 JUPITER 14 48.1 S 9 28.1 +67 12.8 291.9 | -0.4 0.3 0.0 -0.1 SATURN 23 36.3 S 4 43.6 +57 16.6 292.1 | -0.6 0.1 0.0 -0.5 ACRUX 34 05.8 S62 59.5 +38 03.2 202.1 | -1.3 0.0 0.0 -1.3 ALIOTH 27 11.1 N56 03.5 + 9 40.4 341.7 | -5.5 0.0 0.0 -5.5 ALKAID 13 47.2 N49 24.3 +19 11.9 346.1 | -2.8 0.0 0.0 -2.8 AL NA'IR 248 42.7 S47 03.2 + 4 19.0 138.6 | -10.7 0.0 0.0 -10.7 ALPHARD 78 48.6 S 8 34.6 + 7 07.4 263.3 | -7.2 0.0 0.0 -7.2 ALPHECCA 347 00.7 N26 46.7 +43 45.0 7.9 | -1.0 0.0 0.0 -1.0 ALTAIR 283 00.8 N 8 49.3 +15 14.7 74.8 | -3.6 0.0 0.0 -3.6 ANTARES 333 25.1 S26 23.4 +70 09.8 115.4 | -0.4 0.0 0.0 -0.4 ARCTURUS 6 46.9 N19 16.8 +49 29.7 340.4 | -0.8 0.0 0.0 -0.8 ATRIA 328 49.2 S68 59.7 +37 47.2 169.1 | -1.3 0.0 0.0 -1.3 AVIOR 94 56.5 S59 26.7 +10 40.4 210.5 | -5.0 0.0 0.0 -5.0 DENEBOLA 43 27.3 N14 40.5 +30 19.1 300.8 | -1.7 0.0 0.0 -1.7 ELTANIN 311 26.6 N51 29.7 +10 29.1 25.1 | -5.1 0.0 0.0 -5.1 GACRUX 32 57.2 S57 00.3 +42 07.8 207.9 | -1.1 0.0 0.0 -1.1 GIENAH 36 46.2 S17 26.2 +48 54.7 265.0 | -0.9 0.0 0.0 -0.9 HADAR 9 51.7 S60 16.9 +47 07.9 191.9 | -0.9 0.0 0.0 -0.9 KAUS AUS 304 45.0 S34 23.7 +44 22.4 119.9 | -1.0 0.0 0.0 -1.0 MENKENT 9 05.3 S36 16.6 +67 57.1 215.4 | -0.4 0.0 0.0 -0.4 MIAPLACI 82 13.6 S69 38.2 +18 14.1 201.5 | -3.0 0.0 0.0 -3.0 NUNKI 296 57.3 S26 19.2 +37 46.7 109.0 | -1.3 0.0 0.0 -1.3 PEACOCK 274 26.2 S56 47.9 +21 50.0 144.6 | -2.5 0.0 0.0 -2.5 RASALHAG 316 58.0 N12 34.5 +42 08.0 51.5 | -1.1 0.0 0.0 -1.1 REGULUS 68 38.1 N12 03.5 + 9 40.0 286.4 | -5.5 0.0 0.0 -5.5 RIGIL KE 0 54.5 S60 45.4 +47 57.4 185.4 | -0.9 0.0 0.0 -0.9 SABIK 323 09.4 S15 42.1 +60 56.8 88.2 | -0.6 0.0 0.0 -0.6 SHAULA 317 23.9 S37 05.5 +53 45.7 127.5 | -0.7 0.0 0.0 -0.7 SPICA 19 25.9 S11 03.8 +63 41.6 283.9 | -0.5 0.0 0.0 -0.5 SUHAIL 83 39.0 S43 21.2 +12 47.7 228.2 | -4.2 0.0 0.0 -4.2 VEGA 301 24.5 N38 46.2 +14 25.3 39.4 | -3.8 0.0 0.0 -3.8 ZUBENELG 358 01.4 S15 57.8 +84 38.7 304.5 | -0.1 0.0 0.0 -0.1 ARIES 220 28.9

Notes on the data

U.S. Naval Observatory
Astronomical Applications Department

Celestial Navigation Data

Celestial Navigation Data for 1981 Nov 13 at 11:21:00 UT For Assumed Position: Latitude S 19 03.0 Longitude E 6 34.0 Almanac Data | Altitude Corrections Object GHA Dec Hc Zn | Refr SD PA Sum o ' o ' o ' o | ' ' ' ' SUN 354 10.4 S18 00.4 +88 44.6 326.0 | 0.0 16.2 0.0 16.1 VENUS 303 43.7 S26 40.1 +43 51.0 109.1 | -1.0 0.2 0.2 -0.7 MARS 57 28.3 N 8 09.4 +21 18.2 287.2 | -2.5 0.0 0.1 -2.4 JUPITER 17 03.4 S 9 28.1 +65 13.1 289.4 | -0.5 0.3 0.0 -0.2 SATURN 25 51.7 S 4 43.6 +55 17.3 290.2 | -0.7 0.1 0.0 -0.5 ACRUX 36 21.2 S62 59.5 +37 14.3 202.9 | -1.3 0.0 0.0 -1.3 ALIOTH 29 26.5 N56 03.5 + 8 59.0 340.6 | -5.9 0.0 0.0 -5.9 ALKAID 16 02.5 N49 24.3 +18 39.7 344.7 | -2.9 0.0 0.0 -2.9 AL NA'IR 250 58.1 S47 03.2 + 5 44.0 138.0 | -8.7 0.0 0.0 -8.7 ALPHARD 81 04.0 S 8 34.6 + 5 00.4 262.6 | -9.6 0.0 0.0 -9.6 ALPHECCA 349 16.0 N26 46.7 +43 59.6 5.2 | -1.0 0.0 0.0 -1.0 ALTAIR 285 16.1 N 8 49.3 +17 17.9 73.9 | -3.1 0.0 0.0 -3.1 ANTARES 335 40.5 S26 23.4 +72 04.5 117.4 | -0.3 0.0 0.0 -0.3 ARCTURUS 9 02.3 N19 16.8 +48 43.6 337.4 | -0.9 0.0 0.0 -0.9 ATRIA 331 04.6 S68 59.7 +38 10.4 170.0 | -1.3 0.0 0.0 -1.3 AVIOR 97 11.9 S59 26.7 + 9 35.9 210.1 | -5.5 0.0 0.0 -5.5 DENEBOLA 45 42.7 N14 40.5 +28 28.5 299.5 | -1.8 0.0 0.0 -1.8 ELTANIN 313 42.0 N51 29.7 +11 22.2 23.9 | -4.7 0.0 0.0 -4.7 GACRUX 35 12.5 S57 00.3 +41 07.1 208.8 | -1.1 0.0 0.0 -1.1 GIENAH 39 01.6 S17 26.2 +46 47.3 264.5 | -0.9 0.0 0.0 -0.9 HADAR 12 07.1 S60 16.9 +46 39.9 193.4 | -0.9 0.0 0.0 -0.9 KAUS AUS 307 00.3 S34 23.7 +46 13.1 120.2 | -1.0 0.0 0.0 -1.0 MENKENT 11 20.7 S36 16.6 +66 39.9 218.8 | -0.4 0.0 0.0 -0.4 MIAPLACI 84 29.0 S69 38.2 +17 27.3 201.4 | -3.1 0.0 0.0 -3.1 NUNKI 299 12.7 S26 19.2 +39 47.7 108.8 | -1.2 0.0 0.0 -1.2 PEACOCK 276 41.6 S56 47.9 +23 04.1 144.6 | -2.3 0.0 0.0 -2.3 RASALHAG 319 13.4 N12 34.5 +43 46.7 49.5 | -1.0 0.0 0.0 -1.0 REGULUS 70 53.4 N12 03.5 + 7 37.1 285.6 | -6.8 0.0 0.0 -6.8 RIGIL KE 3 09.8 S60 45.4 +47 43.4 187.1 | -0.9 0.0 0.0 -0.9 SABIK 325 24.8 S15 42.1 +63 04.7 87.3 | -0.5 0.0 0.0 -0.5 SHAULA 319 39.3 S37 05.5 +55 26.5 128.6 | -0.7 0.0 0.0 -0.7 SPICA 21 41.2 S11 03.8 +61 36.9 282.2 | -0.5 0.0 0.0 -0.5 SUHAIL 85 54.4 S43 21.2 +11 12.6 227.8 | -4.8 0.0 0.0 -4.8 VEGA 303 39.8 N38 46.2 +15 45.5 38.2 | -3.4 0.0 0.0 -3.4 ZUBENELG 0 16.7 S15 57.8 +82 46.8 294.2 | -0.1 0.0 0.0 -0.1 ARIES 222 44.2

Notes on the data