NN220 Final Exam with all Correct & 100% Verified
Answers |Actual Complete Exam| Already Graded A+
What does Gyro Error find? ✔Correct Answer-bearing of the sun at true SS
What are the 3 vertices in a celestial triangle? ✔Correct Answer-Celestial Body, Celestial Pole,
Zenith
What are the 3 vertices in a Navigation Triangle? ✔Correct Answer-Assumed Position, Geographic
Position, North/South Pole
Planning CELNAV ✔Correct Answer-- first have to understand the apparent movement of CB's
- understand how their azimuth and altitude change (horizontal coordinate system)
- find best stars for CELNAV as CB's
- utilize the Local Hour Angle (LHA): difference between the GHA and Longitude.
What are the reference points of the terrestrial sphere? ✔Correct Answer-North/South Poles,
Prime Meridian, Equator, Great Circle
Earth is the center of the Universe. ✔Correct Answer-True
Celestial Sphere ✔Correct Answer-the projection of al celestial bodies; centered on the Earth
Celestial Coordinate System ✔Correct Answer-the relationship between a CB's declination and
latitude to give us the CB's azimuth and altitude to be projected as a GP from the celestial sphere
Circle of Equal Altitude ✔Correct Answer-A circle of points where the altitude of the CB is
proportional to the distance from its GP. Need 3 or more LOP's for an accurate fix.
Co-altitude ✔Correct Answer-gives distance from a CB's GP on Earth's surface; used as an LOP
Assumed Position (AP) ✔Correct Answer-Where we think we are going to be at a specific time (DR)
Geographic Position (GP) ✔Correct Answer-- Point on Earth's surface projected by the Terrestrial
Sphere
Zenith ✔Correct Answer-our position projected on the celestial sphere if we stood at our AP and
look up at 90 degrees
Altitude-Intercept Method ✔Correct Answer-calculates the range and bearing to a CB's GP
- Ho>Hc = along azimuth/towards GP
- Ho<Hc = opposite of azimuth/ away from GP
How do you determine Gyro Error for SR/SS? (3 steps) ✔Correct Answer-- determine declination of
sun in GMT
- combine declination and latitude to "true amplitude"
- add/subtract the TA to get bearing
What does celestial navigation rely on? ✔Correct Answer-the visible horizon and celestial bodies
, Horizontal Coordinate System ✔Correct Answer-used to specify the position of a CB based on our
AP and their altitude and azimuth from us.
What is Local Hour Angle (LHA)? ✔Correct Answer-the difference between Longitude and the
Observer at their AP and the GHA of a celestial Body at a specific time.
When is true SR/SS? ✔Correct Answer-one semi-diameter above the horizon
When do we take a fix of the sun using a running fix? (Sun Run Sun) ✔Correct Answer-- Morning,
Noon (MERPASS or LAN), Afternoon
- DR
Can we still conduct CELNAV during daylight hours? ✔Correct Answer-Yes
What does a sextant do? ✔Correct Answer-measures the altitude between the visible horizon and
a CB
How to use a sextant for index error? ✔Correct Answer-- observe a flat object or horizon
- move the arm until both images are lined up
- read off the error or off the arc
Index error is described as being... ✔Correct Answer-on the arc or off the arc
on the arc ✔Correct Answer-subtract from sight
off the arc ✔Correct Answer-add to sights
STELLA ✔Correct Answer-...
What does STELLA stand for? ✔Correct Answer-System To Estimate Latitude and Longitude
Astronomically
What are the functions of STELLA? (3) ✔Correct Answer-- calculate time using SR/SS/Twilight
- perform gyro check using the sun at sunset
- find a fix using the altitude-intercept method
color of 3 best stars ✔Correct Answer-yellow
color of 4-7 next best stars ✔Correct Answer-red
color of stars that are not the best for use ✔Correct Answer-blue
3 best stars depend on what 3 things? ✔Correct Answer-Magnitude, Separation, Altitude
7 best stars listed depend on what 2 things? ✔Correct Answer-Time, Assumed Position (AP)
STELLA was created to do what? ✔Correct Answer-reduce workload and need for hard copy pubs
What pubs/ resources does STELLA use? ✔Correct Answer-Nautical Almanac, Sight Reduction
Tables
Answers |Actual Complete Exam| Already Graded A+
What does Gyro Error find? ✔Correct Answer-bearing of the sun at true SS
What are the 3 vertices in a celestial triangle? ✔Correct Answer-Celestial Body, Celestial Pole,
Zenith
What are the 3 vertices in a Navigation Triangle? ✔Correct Answer-Assumed Position, Geographic
Position, North/South Pole
Planning CELNAV ✔Correct Answer-- first have to understand the apparent movement of CB's
- understand how their azimuth and altitude change (horizontal coordinate system)
- find best stars for CELNAV as CB's
- utilize the Local Hour Angle (LHA): difference between the GHA and Longitude.
What are the reference points of the terrestrial sphere? ✔Correct Answer-North/South Poles,
Prime Meridian, Equator, Great Circle
Earth is the center of the Universe. ✔Correct Answer-True
Celestial Sphere ✔Correct Answer-the projection of al celestial bodies; centered on the Earth
Celestial Coordinate System ✔Correct Answer-the relationship between a CB's declination and
latitude to give us the CB's azimuth and altitude to be projected as a GP from the celestial sphere
Circle of Equal Altitude ✔Correct Answer-A circle of points where the altitude of the CB is
proportional to the distance from its GP. Need 3 or more LOP's for an accurate fix.
Co-altitude ✔Correct Answer-gives distance from a CB's GP on Earth's surface; used as an LOP
Assumed Position (AP) ✔Correct Answer-Where we think we are going to be at a specific time (DR)
Geographic Position (GP) ✔Correct Answer-- Point on Earth's surface projected by the Terrestrial
Sphere
Zenith ✔Correct Answer-our position projected on the celestial sphere if we stood at our AP and
look up at 90 degrees
Altitude-Intercept Method ✔Correct Answer-calculates the range and bearing to a CB's GP
- Ho>Hc = along azimuth/towards GP
- Ho<Hc = opposite of azimuth/ away from GP
How do you determine Gyro Error for SR/SS? (3 steps) ✔Correct Answer-- determine declination of
sun in GMT
- combine declination and latitude to "true amplitude"
- add/subtract the TA to get bearing
What does celestial navigation rely on? ✔Correct Answer-the visible horizon and celestial bodies
, Horizontal Coordinate System ✔Correct Answer-used to specify the position of a CB based on our
AP and their altitude and azimuth from us.
What is Local Hour Angle (LHA)? ✔Correct Answer-the difference between Longitude and the
Observer at their AP and the GHA of a celestial Body at a specific time.
When is true SR/SS? ✔Correct Answer-one semi-diameter above the horizon
When do we take a fix of the sun using a running fix? (Sun Run Sun) ✔Correct Answer-- Morning,
Noon (MERPASS or LAN), Afternoon
- DR
Can we still conduct CELNAV during daylight hours? ✔Correct Answer-Yes
What does a sextant do? ✔Correct Answer-measures the altitude between the visible horizon and
a CB
How to use a sextant for index error? ✔Correct Answer-- observe a flat object or horizon
- move the arm until both images are lined up
- read off the error or off the arc
Index error is described as being... ✔Correct Answer-on the arc or off the arc
on the arc ✔Correct Answer-subtract from sight
off the arc ✔Correct Answer-add to sights
STELLA ✔Correct Answer-...
What does STELLA stand for? ✔Correct Answer-System To Estimate Latitude and Longitude
Astronomically
What are the functions of STELLA? (3) ✔Correct Answer-- calculate time using SR/SS/Twilight
- perform gyro check using the sun at sunset
- find a fix using the altitude-intercept method
color of 3 best stars ✔Correct Answer-yellow
color of 4-7 next best stars ✔Correct Answer-red
color of stars that are not the best for use ✔Correct Answer-blue
3 best stars depend on what 3 things? ✔Correct Answer-Magnitude, Separation, Altitude
7 best stars listed depend on what 2 things? ✔Correct Answer-Time, Assumed Position (AP)
STELLA was created to do what? ✔Correct Answer-reduce workload and need for hard copy pubs
What pubs/ resources does STELLA use? ✔Correct Answer-Nautical Almanac, Sight Reduction
Tables
