Transcript Slide 1

Navigation
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Sight Folder Requirements
hs between 15º and 75º; LOP with 3.0nm
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Line of Position (LOP) using the Sun
from run of at least three qualified sights
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Line of Position (LOP) using the Moon
from run of at least three qualified sights
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Line of Position (LOP) using a Star
from run of at least three qualified sights
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Line of Position (LOP) using a Planet
from run of at least three qualified sights
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Meridian Transit of the Sun
from run of at least three sights with one
sight within 10 sec of MT
Sight within 10sec of calculated MT
reduced using the Meridian Transit
SR form.
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2-body Fix using any two bodies
from a run of at least three qualified
sights each; taken within 20 mins and
intersection of LOP’s not less than 45º
Selected sights must be reduced and
plotted by both the NASR and LOC
method.
Any one of these sights must be
reduced and plotted by the Nautical
Almanac Sight Reduction (NASR)
method. One sight from each of the
other three must be reduced and
plotted using the Law of Cosines
(LOC) method.
APPENDIX D
Minimum of 21 sights
7 SR Form / 6 CLS SAP
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Navigation
Monday
Tuesday
Wednesday
Thursday
31 Mar
1 April
2
3
Friday
4
Saturday
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6
1123-1223
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8
9
10
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1125
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15
16
1502-1657
1546-1726
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22
23
28
27
30
1634-1729
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6
1129-1259
1128-1228
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19
20
24
25
26
27
1 May
2
3
4
1717-1727
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1131-1141
1409-1529
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1127
5
1122-1237
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1321-1341
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Sunday
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10
1130-1235
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Navigation
Chapter 1
View of our Solar System
Chapter 2
Sunrise … Sunset
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Learning Objectives
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Apparent motion
‘First Point of Aries’
Sidereal Hour Angle (SHA)
Difference between solar & sidereal time
Difference between LMT & ZT
Determine ZT Sun/Moon rise/set
Determine ZT civil & nautical twilight
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Night Sky
Sep 22
-21.3sec
Dec 21 +29.9sec
+31.1sec
Jun 21
-18.1sec
Mar 20
Solar Time
Orbit time: 31,536,000 SI seconds
86,400.002 seconds/day
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Night Sky
SUMMER SOLSTICE
Jun 21
Dec 23º 26.1’ N
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Night Sky
AUTUMNAL EQUINOX
NP
Sep 22
Dec 0º 00.0’
SP
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Night Sky
WINTER SOLSTICE
Dec 21
Dec 23º 26.1’ S
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Night Sky
VERNAL EQUINOX
NP
Mar 20
Dec 0º 00.0’
SP
First point of Aries ()
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Night Sky
Sidereal Time
23hr 56min 4.0916sec
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Celestial
Equator
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GHA
Celestial
Equator
= SHA
+ GHA
NP

G
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Sight Reduction Form
19 Mar 20xx
13-00-00
00-03
+
13-00-00
5
+
18-00-00
20 Mar 20xx
?
?
193 51 3
45 00 0
92 30 0

g
G

18
00 - 00
?
?
Dubhe
–
88 25 8
0 00 0

282 17 1
92 30 0
189 47 1
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Night Sky
VENUS
JUPITER
MARS
MOON
SATURN
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Navigator’s Solar System
Sun – Moon – 4 Planets – 57 Stars
-26.7 -13.2
NA
South Declination
North Declination
1st Magnitude
1st Magnitude
Sirius (-1.5)
Arcturus (0.0)
Canopus (-0.7)
Vega (0.0)
Rigil Kentaurus (-0.3)
Betelgeuse (0.1)
Rigel (0.1)
Capella (0.1)
Achernar (0.5)
Procyon (0.4)
Spica (1.0)
Altair (0.8)
Antares (1.0)
Aldebaran (0.9)
Fomalhaut (1.2)
Regulus (1.1)
Acrus (1.3)
Pollux (1.1)
Adhara (1.5)
Deneb (1.3)
Gacrux (1.6)
Bellatrix (1.6)
Shaula (1.6)
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Capella
Betelgeuse
Bellatrix
Alnilam
Rigel
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Horizon, planets and brightest stars visible
Morning Sights
Evening Sights
Between
beginning of CT
and sunrise
Between
sunset
and end CT
0643 – 0712
29min
1923 – 1952
29min
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Solar P-hen-omen-a
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Sunrise (SR)
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Sunset (SS)
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Twilight
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Civil Twilight (CT)
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Nautical Twilight (NT)
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Local Mean & Zone Time
Local Mean Time (LMT) –
based on the mean sun with
reference to the local celestial
meridian.
DLo – difference between
your Lo and referenced
meridian.
Zone Time (ZT) –
based on the nearest meridian
with a longitude exactly
divisible by 15°.
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Local Mean & Zone Time
1814 ZT
1814 LMT
92.5° W
?
97.5° W
ZM
90° W
ZD +6
82.5° W
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Local Mean & Zone Time
Zone Time: 1814
Location: Lo 92° 42.6’ W
1. FIND ZM:
2. FIND DLo:
92° 43’ – 90° = 2° 43’ = 2.7°
3. DLo to TIME: 2.7° x 4min = 10.8min; rounded 11min
(15° in 1hr; 1° in 4min)
1814 - 11min = 1803
4. LMT:
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Predicting Phenomena
Location: L 48° 20.7’ N
Lo 92° 42.6’ W
Find LMT for beginning of
morning CT.
Tab Lat
50°
45°
5°
LMT CT
0718
0704
14min
Latitude: 48° 20.7’ N
45° 00.0’ N
3° 20.7’ = 3.35°
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Predicting Phenomena
Diff Tab Lat: 5°
Diff LMT:
14min
Diff Lat:
3.35°
LMT CT L 45° N
0704
Corr for L 48° 20.7’ N
+ 9min
LMT CT L 48° 20.7’ N 0713
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Predicting Phenomena
LMT CT L 48° 20.7’ N 0713
DLo = DR Lo – ZM
Lo 92° 43’ W
ZM 90° 00’ W
DLo 2° 43’ W = 2.7°
2.7° x 4min = 10.8 rounded 11min
LMT
0713
DLo (W) + 11
LMT for CT 0724
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Predicting Phenomena
How would I
use this skill?
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Predicting Phenomena
ABOARD MOVING VESSEL
“First Estimate”
ZT 0000 GPS Position
L 45° 26’ N; Lo 11° 39’ W
Course 115° T; Speed 9.0kn
Tab L 45° N NT = 0627
(Lo 15° W)
When do you need
to be on deck for
morning sights?
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Predicting Phenomena
ABOARD MOVING VESSEL
“First Estimate”
0627-0000 = 6hr 27min = 387min
How far will you
travel by tab LMT
NT?
Plot projected 0627 DR position
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Predicting Phenomena
0000 GPS
0000 GPS
L 45° 26’ N
Lo 11° 39’ W
20’
10’
Projected
L 45° 01.5’ N
Lo 10° 46.4’ W
45°N
50’
40’
30’
20’
10’
11° W
50’
40’
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Predicting Phenomena
ABOARD MOVING VESSEL
“First Estimate”
Projected DR
L 45° 01.5’ N - Lo 10° 46.4’ W
Tab L
50° N
45° N
5°
LMT NT
0637
0627
10min
What’s are
the the
differences
difference between
in Tab
Lat
EP Lat
& LMT
& Tab
NT?
L?
45° 01.5’ N – 45° 00.0’ N = 1.5’
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Predicting Phenomena
ABOARD MOVING VESSEL
“First Estimate”
What’s the LMT NT
at projected Lat?
LMT NT: 0627 + 0 = 0627
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Predicting Phenomena
ABOARD MOVING VESSEL
“First Estimate”
LMT Projected Lat = 0627
DLo: 15° 00.0’ W – 10° 46.4’ W
4° 13.6’ W = -4.2°
4.2° x
4min
=
16.8min
What’s
NT
What’sthe
theLMT
arc to
What’s your DLo?
at
projected
DR?
time
conversion?
rounded 17min
LMT NT: 0627 – 17min = 0610
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Navigation
Next week bring your calculator or abacus
CHAPTER 6
SIGHT PLANNING
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View of our Solar System
Sunrise / Sunset
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