Basic navigation - AE Flashcards
Hvað er aphelion?
Þar sem jörðin er fjærst sólu á sporbaug sínum.
The apparent sun is always in the plane of the ___.
ecliptic
Hvað er Perihelion?
Þar sem jörðin er næst sólu á sporbaug sínum. Hér er jörðin á mestum hraða í sporbaugnum.
At mid-latitudes where is the relationship between length of day and night as well as rate of change of declination of sun, chaning at the greatest rate?
Spring equinox and autumn equinox
Hvað er ecliptic? The ___ apparent path of the __ around the ___.
yearly, sun, earth.
Hvernig finnur þú distance á milli longitude?
1° longitude er 60 minutes. Svo segir þú distance = change in longitude in minutes * cos(latitude)
True direction at the vertex of a great circle is always _° or _°.
90° or 270°
A meridian and it’s anti meridian form a complete __ ___.
great circle
Latitude may be defined as the angular ___ measured along a meridian from the equator to a parallel of the ___.
distance, latitude
Hvað er annað nafn yfir Orthodromic line?
Great circle line
The poles are the points of intersection between the earth’s ___ and the surface of the earth
axis
The compression factor of the earth is so small that it may be ignored when making ordinary maps and charts. It is about 1:X.
1:300
Hver er formúla convergence?
Convergence = dlong * sin(mean lat)
dlong: degrees longitude
Hver er formúla departure
departure = cos(lat) * minutes
Hvað reiknar convergence?
Hvað great circle track sveigist mikið út frá braut. T.d. væri convergence 10° að þýða að í upphafi ferðar myndi leiðin sveigjast 5° að pól og svo sveigjast 5° til baka seinni hluta ferðarinnar. (5° væri þá svokallað convergence angle).
Hvað reiknar departure?
Departure reiknar vegalengd á milli tveggja meridians.
Ef þú vilt fljúga constant true track, hvernig leið/track þarftu að velja?
rhumbline
The earth may be referred to as
a) elliptical
b) an oblate spheroid
b) an oblate spheroid
The sun is _ minutes to travel 1°
4
Which is more accurate, UTC or GMT?
UTC
_____ causes the sunrise to occur earlier and the sunset to occur later.
atmospheric refraction
A day is __ successive transits of a heavenly body
two
The time interval between sunrise and sunset is dependent on the __ of the sun and the __ of the observer
declenation, latitude
Hvort er lengra twilight at high latitudes eða low latitudes?
high latitudes