zenith distance

The telescope must be slewed to 77° zenith distance north to allow access to the prime focus cage.

This is referred to as the True Zenith Distance.

The positions are accurate to about 10" rms and the zenith distances ignore refraction.

This effect results from the different slants at which the zenith distances cause the cones to intersect the flight ceiling.

The effect of solar parallax on zenith distance was known to Indian astronomers right from Aryabhata.

Portuguese mariner's astrolabes are unique because they are graduated for zenith distance only.

By subtracting this from 90 he would find that the zenith distance is 90 , which is his latitude.

In short, the zenith distance of a heavenly object at meridian altitude is the difference in latitude between it and the observer.

The terrestrial latitude of an observer's position is equal to the zenith distance of the Sun at noon on the equinctial day.

This double numbering enables the instrument to measure either celestial altitude or zenith distance or both simultaneously.

Quadrant Altazimuth, six feet in radius, for measuring altitudes or zenith distances of celestial bodies.

The microscopes on the limb are then read off, and thus the apparent zenith distance of the collimating point, intersection of the wires, is found.

Elevation is the angular height of an object above the horizon, Alternatively zenith distance, being equal to 90 degrees minus elevation.

Alternatively, zenith distance, the distance from directly overhead (i.e. the zenith) may be used instead of altitude.

They are used for the measurement of small differences of zenith distance, and used in the determination of astronomic latitude.

Plotting the vertical component of the pointing error against zenith distance (Figure 7) reveals significant tube flexure (or perhaps elevation runout).

This is then subtracted from 90 to obtain the angular distance from the position directly above to obtain the zenith distance.

Dakshin Bhitti Yantra (measures meridian, altitude and zenith distances of celestial bodies)

Atmospheric refraction shifts the apparent positions of objects by an amount dependent on the zenith distance of the object and the wavelength of observation.

Because the H.O. 214 expresses the vertical position of the moon in terms of its altitude, instead of its zenith distance, a conversion is required.

The tube is suspended by trunnions at the top and swings against a graduated arc extending north and south for measuring zenith distances in the meridian.

The angle of a celestial body with the zenith is the zenith angle (in astronomy, commonly referred to as the zenith distance).

At noon, the sun's pinhole image falls on a scale below enabling the observer to measure the zenith distance, declination, and the diameter of the Sun.)

In practice it is not necessary to use zenith distances, which are 90 minus altitude, as the calculations can be done using observed altitude and calculated altitude.

By reading the position of the lower rod, in combination with the vertical length, the zenith distance (or, alternatively, the altitude) of a celestial object could be calculated.