octant
Sextant's smaller cousin
An octant is one of eight parts into which three-dimensional space is divided by three mutually perpendicular planes, analogous to a quadrant in two dimensions.
In navigation and astronomy, an octant is an instrument resembling a sextant but with an arc of 45 degrees (one eighth of a circle) rather than 60, used historically for measuring angles between celestial bodies and the horizon.
Precision angle-measuring instrument
- astrolabeAncient altitude-measuring instrument
- cross-staffAltitude-measuring navigation instrument
- arcCurved line segment
- mirrorReflective viewing surface
Ancient altitude-measuring instrument
- compassDevice showing cardinal directions
- longitudeEast-west angular distance
- latitudeGeographic or personal freedom
- bearingPosture or orientation
chart · course · altitude · azimuth · horizon · meridian · chronometer · pilotage
Point straight overhead
- nadirLowest possible point
- eclipticSun's apparent annual path
- declinationAngular distance from equator
- altitudeMeasured height above reference
theodolite
Precision angle-measuring instrument
- astrolabeAncient altitude-measuring instrument
- cross-staffAltitude-measuring navigation instrument
- arcCurved line segment
astrolabe
Ancient altitude-measuring instrument
- compassDevice showing cardinal directions
- longitudeEast-west angular distance
- latitudeGeographic or personal freedom
bearing · chart · course · altitude · azimuth · horizon · meridian · chronometer · pilotage · waypoint
zenith
Point straight overhead
- nadirLowest possible point
- eclipticSun's apparent annual path
- declinationAngular distance from equator
altitude · azimuth · horizon · observatory
eighth
Ordinal for eight
- divisionSplitting into parts
- three-dimensionalHaving volume and depth
- CartesianOf x-y coordinate geometry
x-axis · y-axis · z-axis · positive · negative · spatial · hemisphere · origin · plane · region
ship
Seagoing transport vessel
navigation · deck · captain · mariner · sailing · ocean · naval
octantquadrant
Fourth of a circle
whole · full circle · hemisphere · semicircle · half
- high octaneIntensely energetic or powerful
- octane ratingFuel's anti-knock measurement
- low octaneLow-grade gasoline rating
- octane numberFuel combustion resistance rating
- regular octagonEight congruent sides and angles