arcsecond
Tiny sky measurement
An arcsecond is a unit of angular measurement equal to one sixtieth of an arcminute, or one 3,600th of a degree.
It is used primarily in astronomy, navigation, and geodesy where extremely precise measurements of position or separation are required.
The apparent diameter of celestial objects and the distances between stars are often expressed in arcseconds.
The telescope can resolve details as small as 0.5 arcseconds.
Position change from different vantages
- astrometryMeasuring celestial body positions
- declinationAngular distance from equator
- parsecInterstellar length measure
- observatoryFacility for celestial study
star catalog · angular resolution · double star · positional astronomy · epoch · celestial sphere · altitude · azimuth
Instrument magnifying faraway objects
- apertureAdjustable optical inlet
- focal lengthLens-to-convergence-point distance
- magnificationDegree of visual enlargement
- eyepieceLens you look through
CCD · detector · interferometry · baseline · image sharpness · collimation · field of view · astrophotography
Accuracy of measurement
- degreeUnit of measurement
- radianArc-length angle unit
- resolutionFormal decision or determination
- accuracyDegree of correctness
Measuring and charting terrain
- triangulationLocation via three points
- theodolitePrecision angle-measuring instrument
- land measurementQuantifying terrain area
- cadastralOf property boundaries
mapping · cartography · GPS positioning · baseline measurement · control point
parallax
Position change from different vantages
- astrometryMeasuring celestial body positions
- declinationAngular distance from equator
- parsecInterstellar length measure
observatory · star catalog · angular resolution · double star · positional astronomy · epoch · celestial sphere · altitude · azimuth
telescope
Instrument magnifying faraway objects
- apertureAdjustable optical inlet
- focal lengthLens-to-convergence-point distance
- magnificationDegree of visual enlargement
eyepiece · CCD · detector · interferometry · baseline · image sharpness · collimation · field of view · astrophotography
precision
Accuracy of measurement
- degreeUnit of measurement
- radianArc-length angle unit
- resolutionFormal decision or determination
accuracy · calibration · micrometer · subdivision · sampling
surveying
Measuring and charting terrain
- triangulationLocation via three points
- theodolitePrecision angle-measuring instrument
- land measurementQuantifying terrain area
cadastral · mapping · cartography · GPS positioning · baseline measurement · control point
arcseconddegree
Unit of measurement
radian · arcminute · full rotation · revolution · full circle