it is line set out by the optical axis of the instrument ( level). so it is just an imaginary line that describes the ray of light that allowes us to read different values from the leveling staff. this term arose from the fact that in differential leveling in surveying we must construct horizontal line of sight, but due to collimation error the collimation line (i.e. line of sight) will not be 100% horizontal (by horizontal we mean tangent the level surface at the instrument position), instead it will be slightly deviated. so what we are looking to achieve when we eliminate the collimation error (using the 2 peg test) is a horizontal line of collimation.
to levelling the soil.
The answer will depend on what is required for the 464 sq feet: painting it, concreting it, tiling it, levelling it, etc.
A line of best-fit.
A line intersect is a point on a line where another line or object crosses the line.
A straight line, a telephone line, a shipping line, a fishing line.
This term is used in surveying. 'Height of collimation' means height of instrument.Generally this term is used while doing levelling i.e. Measuring elevation of given point.
there are few types of errors in levelling...... these arr...... 1- instrumental error 2- collimation error 3- errors due to curvature and refraction 4- some other errors also
The height of collimation is the height of the line of sight. It is the vertical distance of the horizontal plane through a telescope.
error in alignment between the optical axis of a telescope & the declination. it is line set out by the optical axis of the instrument ( level). so it is just an imaginary line that describes the ray of light that allows us to read different values from the leveling staff. this term arose from the fact that in differential leveling in surveying we must construct horizontal line of sight, but due to collimation error the collimation line (i.e. line of sight) will not be 100% horizontal (by horizontal we mean tangent the level surface at the instrument position), instead it will be slightly deviated. so what we are looking to achieve when we eliminate the collimation error (using the 2 peg test) is a horizontal line of collimation.
Is error comes when the line of sight does not coincide with the optical axis of theodolite.
diaphragm
levelling
basically two types of levelling.. 1.Direct Levelling 2.Indirect Levelling. further they can be classified as well.
there are commonly five tpes of levelling:- 1.simple levelling 2.differential 3.reciprocal levelling 4.profile levelling 5.cross section levelling
Collimation Error: Collimation error occurs when the collimation axis is not truly horizontal when the instrument is level. The effect is illustrated in the sketch below, where the collimation axis is tilted with respect to the horizontal by an angle α: Figure ( ) In this particular example, the effect is to read too high on the staff. For a typical collimation error of 20", over a sight length of 50m the effect is 5mm. If the sight lengths for back sight and foresight are equal, the linear effect is the same for both readings. When the height difference is calculated, this effect cancels: δh = (b + s. α) - (f + s. α) = b - f That is, the effect of the collimation error is eliminated if sight lengths are kept equal.
Collimation is used for telescopes to make sure the telescopes are perfectly aligned. The reflector will not produce the best image if the aligned is not just right.
Levelling the Land was created in 1991-09.