AVS

Question 1

What is your latitude if you are sailing in the northern hemisphere while the sun is in the southern hemisphere, with the sextant angle taken during meridian passage of 42°06.7’ and the declination 5°24.9’?

Answer 1

53°18.2’N

Question 2

What is formed by arcs of a celestial meridian, an hour circle, and a vertical circle, and its vertices are the elevated pole, the zenith, and a point on the celestial sphere?

Answer 2

Navigational triangle

Question 3

Which coordinate is a vertical circle through the east and west points of the horizon and is perpendicular to the principal vertical circle?

Answer 3

D

Question 4

Which publication is updated annually?

Answer 4

Nautical Almanac

Question 5

What is the plane of the sensible horizon if the observer is at the center of the Earth?

Answer 5

Celestial horizon

Question 6

Your vessel is at sea on June 22, 2023 with DR position 32°30’ N 061°55’W . As an OOW, you are taking your position by meridian passage at 1202H with the sun’s sextant altitude of 80°55.8’ in the same hemisphere. With the following date, solve each item to determine your latitude. How much is the zenith angle?

Answer 6

8°51.4’

Question 7

What is perpendicular to the plane of the instrument when properly adjusted?

Answer 7

B

Question 8

What is the purpose of the part indicated by letter “E”?

Answer 8

To receive the image from the index mirror and reflect it back to the observer through the telescope

Question 9

Which chart projects the equatorial stars of the eastern hemisphere?

Answer 9

B

Question 10

Which is NOT TRUE about meridian passage?

Answer 10

This takes place always at precisely 12 noon.

Question 11

Analyze which star has the azimuth of 230°

Answer 11

Altair

Question 12

What is the sextant altitude of the body based on this reading?

Answer 12

29°42.5’

Question 13

Which chart projects the stars with declination between 30° and 90° south?

Answer 13

B

Question 14

Which star is used as a preference to find a position that gives 90° altitude, which is the same as your latitude when it is directly overhead if you are at the north pole?

Answer 14

Polaris

Question 15

Which is TRUE about latitude by meridian passage position fixing method?

Answer 15

the position line that the latitude by meridian passage method will be parallel to the meridians of longitude

Question 16

Which position is illustrated in the Figure?

Answer 16

Latitude from Polaris

Question 17

Which point of celestial sphere is indicated by letter “B”?

Answer 17

nadir

Question 18

Which position fixing method is illustrated in the Figure?

Answer 18

Sun-Run-Sun

Question 19

What is the True Observed altitude of the sun?

Answer 19

81°08.6’

Question 20

Who stated that when a body is acted upon by an external force, its acceleration if directly proportional to that force?

Answer 20

Isaac Newton

Question 21

Which publication contains such information?

Answer 21

Nautical almanac

Question 22

Why are Mercury & Venus considered as inferior planets?

Answer 22

The orbits of Mercury & Venus are closer to the sun than the Earth’s orbit

Question 23

Which letter represents to Sidereal Hour Angle?

Answer 23

B

Question 24

Which error affects the part indicated by letter “E”?

Answer 24

Index error

Question 25

Which system of coordinates are star charts based upon?

Answer 25

Celestial equator system

Question 26

How much is the earth’s obliquity of the ecliptic relative to its orbital plane??

Answer 26

23°26’

Question 27

Which celestial body are you calculating if you are using this table?

Answer 27

star

Question 28

Calculate the intercept of the body using the following data

Answer 28

0°19.9’ Away

Question 29

Calculate the intercept of the body using the following data:

Answer 29

0°09’ Towards

Question 30

What is the True Observed altitude of the sun?

Answer 30

80°55.6’

Question 31

What is the angular distance from A to a point on the celestial sphere and is measured along a vertical circle from 0° through 180°?

Answer 31

Azimuth

Question 32

Which chart projects the Northern stars?

Answer 32

C

Question 33

Which position is Venus plotted from?

Answer 33

AP3

Question 34

How do you acquire the index error?

Answer 34

By looking obliquely into the horizon mirror so you can see the graduated arc & its reflection, then adjust the micrometer drum where the line points at 0°

Question 35

How much is the dip correction based on the Table?

Answer 35

2.8

Question 36

What does arc GM indicate?

Answer 36

Longitude-West

Question 37

Which group of planets is commonly used in navigation?

Answer 37

Venus, Mars, Jupiter, Saturn

Question 38

Which is NOT an advantage of using longitude by meridian passage in position fixing?

Answer 38

Uses single line of position

Question 39

Which body is plotted from AP3?

Answer 39

Venus

Question 40

Which celestial body are you calculating if you are using this table?

Answer 40

Sun

Question 41

What is the advantage of this method of position fixing?

Answer 41

relies on accurate measurement of course & distance travelled to calculate the transfer

Question 42

Calculate the intercept of the body using the following data:

Answer 42

37°56.8’

Question 43

Which star or planet is plotted from AP2?

Answer 43

Capella

Question 44

What is known as the hour circle through the vernal equinox?

Answer 44

First point of Aries

Question 45

What is your latitude?

Answer 45

31°53.6’

Question 46

What is your latitude if you are sailing in the northern hemisphere, same as the sun’s, with sextant angle taken during meridian passage of 42°06.7’ and the declination is 5°24.9’?

Answer 46

42°28.4’S

Question 47

Which point is indicated by letter “E”?

Answer 47

Azimuth

Question 48

Which formula of meridian passage is used to solve for latitude if you are in the opposite hemisphere of the sun?

Answer 48

(90° – Sextant Angle) – Declination of the sun

Question 49

What is the correct term for letter ”D corresponding to other celestial coordinate system?

Answer 49

Declination

Question 50

What is the correct term for letter ”C” corresponding to other celestial coordinate system?

Answer 50

Celestial Sphere

Question 51

What is the Zn of Venus?

Answer 51

230° (Towards)

Question 52

Which point of celestial sphere is indicated by letter “A”?

Answer 52

Nadir

Question 53

Which part of the almanac gives the time for meridian passage based on the Figure?

Answer 53

D

Question 54

What is the concept of the figure?

Answer 54

Illustrates relationship between various hour angles & meridian angles

Question 55

Which publication contains all the tables required for coastal & deep sea navigation, a simple uniform method of interpolation for all the trigonometric tables, certain tables and data which are not readily available on board ship or are only used in the examination room?

Answer 55

Nautical Almanac

Question 56

What is the advantage of this method of position fixing?

Answer 56

Plotting latitude on the chart without the need to measure any bearings

Question 57

Which statement is NOT true about Keppler’s planetary law of motion?

Answer 57

The squares of the sidereal periods of any two planets are proportional to the cubes of their mean distances from the sun

Question 58

What is the hour circle of the vernal equinox if measured from the observer?

Answer 58

PsΥ

Question 59

When should this position fixing method be best taken?

Answer 59

Noon

Question 60

In the horizon system of coordinates, which coordinate is similar to the meridians of longitude?

Answer 60

C

Question 61

Which formula of meridian passage is used to solve for latitude if you are in the same hemisphere of the sun?

Answer 61

(90° – Sextant Angle) + Declination of the sun

Question 62

What is the latitude of the fix position?

Answer 62

24°43’ N

Question 63

Which is TRUE about inferior and superior planets?

Answer 63

Superior planets can pass behind the sun but cannot pass between the sun and the earth

Question 64

What is the correct term for letter ”A” corresponding to other celestial coordinate system?

Answer 64

Ascension

Question 65

Which star or planet is plotted from AP1?

Answer 65

Vega

Question 66

Which publication consists three volumes of comprehensive tables of altitude and azimuth designed for the rapid reduction of astronomical sights in the air?

Answer 66

Sight Reduction Table

Question 67

Which is NOT an advantage of the intercept method of position fixing?

Answer 67

Using a complete set of stars at a single point in time allows you to calculate a full position fix

Question 68

What do letters A & B signify in the illustration?

Answer 68

Celestial coordinates

Question 69

What does letter “C” stand for?

Answer 69

Greenwichhourangle

Question 70

Which part measures the minute of a degree?

Answer 70

D