7/27/2019 Celestial Navigation Diagnostic Test1

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I. Fill in the blanks:

1._____________controls the way things move and responsible for the motion of the Sun, the oon andthe stars in our sky as well.

!.__________________is responsible for seasons.

".___________________is composed of the Sun and the collection of celestial bodies that orbit it. #hese

include the nine planets $ercury, %enus, &arth, ars, 'upiter, Saturn, (ranus, )eptune and *luto+.

.-t______________the &arth is nearest from the Sun.

. -t_______________ the &arth is farthest from the Sun.

/. #he two points at which the ecliptic crosses the e0uator are called_______________.

.2hen the sun reaches its ma3imum declination of about !"o!4 ) or S is called______________.

5.#he______________________ is the longest day of the year.

6.#he_______________________is the shortest day of the year.

17. #he__________________is an imaginary sphere of gigantic radius with the earth located at its center.

11. #he_______________________is best understood as a pro8ection of the terrestrial coordinate system.

1!.9n the celestial sphere latitude becomes_____________________.

1". ongitude becomes______________________, measured from the vernal e0uino3.

1._______________________is similar to a parallel of latitude on earth.

1.#he hori;on coordinate system is based on the______________________________.

II ultiple s+ from the visible to the sensiblehori;on=

a. inde3 error b. dip c. refraction d. altitude correction

". - position obtained by observation of celestial bodies is called:a. ?@ position b. -ssumed position c. 9bserved position d. &stimated position

. Standard time applied at sea according to the ;one which is 1 degrees or one hour is:

a. apparent time b. civil time c. ;one time d. mean time

. #ime based upon the true position of the sun as distinguished from mean time which is measured by a

fictitious sun moving at a uniform rate is called:

a. apparent time b. civil time c. ;one time d. mean time

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7/27/2019 Celestial Navigation Diagnostic Test1

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/. #ime reckoned at each particular places from an epoch determined by the local convenience is called:

a. local apparent time b. local civil time c. local ;one time d. local mean time

. - delicate time piece used to indicate the A# is called:

a. stop watch b. chronograph c. chronometer d. time signal

5. #he earth4s a3is has a fi3ed inclination from a line perpendicular to the plane of the orbit. #his

inclination is e0uals to:

a. !"o!4 b. 1 radian c. //.o d. ".116

6. @eflected angle is e0ual to the angle of incidence is one of the three optical principles in the construction

of a:a. se3tant b. pelorous c. compass d. gyro compass

17. #he best heavenly body to observe for longitude is the :

a. moon b. sun c. star d. planets

11. #he method in which you observe the true altitude of the sun and subtract from 67o to get your BC thenapplying your declination either plus or minus to get your observe latitude is:

a. e3 D meridian c. longitude factor

b. meridional ;enith distance d. none of these

1!. #he time measured by hour angle of the mean sun plus 1! hours if less than 1! hours and minus 1!

hours if more than 1! hours.

a. apparent time b. sidereal time c. mean time d. none of these

1". #he time measured on celestial e0uator from ower branch of the observer4s meridian westward to hour

circle through the sun from 7 hour to ! hour.

a. local mean time b. ;one time c. local apparent time d. sidereal time

1. 2hen the e0uation of time is taken from the )autical almanac for the use in celestial observation, it is

used to determine:

a. local mean time b. sunrise c. ;one time d. local apparent noon

1.#he difference of latitude between the geographical position and your position, at the time of upper

transit is represented by:

a. ;enith distance b. coaltitude c. altitude d. codistance

III *roblem Solving:

1. #he ;one time in ongitude 1/6o!42 was 11> "7 !S. Find the local mean time.

!. -t A# 75> "7 1s, the chronometer reads 75> "1 15S. 2hat is the chronometer error=

Solution:

". -ldebaran was observed on the meridian bearing South with a true altitude of o.!4,declination 17o7.!4 ). Find the latitude at time of sight

. 9n ay "7, !77/ at 76> "7 77S A#, the true altitude $>o+ of the sun was observed to be 7o74.

#he vessel is ?@ !o"!4 S, 76o"4&. ?eclination of the sun is 11o4s and the A>- is 77o"4. Find thetrue a;imuth and intercept.

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