A circle of radius 7 m has a standard error of 0.02 m on the radius. The standard error of its area is
Area of circle
A = πr2
∴ dA/dr = 2πr
Let standard error in radius be er,
∴ Standard error in area,
Geodetic surveying is different from plane surveying because of
The difference between the most probable value of a quantity and its observer value is
True Error = Actual Value-Observed Value
Weighted Observations=Observations taken with proportion to any quantity like an area
Conditional Error= Error occurring due to certain conditions prevailing. Like temperature error.
Residual Error = Most Probable Value- Observed Value
The error due to bad ranging is
Cumulative Errors occurring in same direction and thus, they aggregate to make a considerable amount of error.
Positive cumulative errors Non Horizontality, sag, bad ranging.
Positive/ Negative cumulative errors Erroneous length of chain, temperature variation.
For a well-conditional triangle, no angle should be less than
For a well-conditioned triangle all the angles must lie in the range of 300-1200.
An invar tape is made of an alloy of
The distance measured right or left of the chain line to locate details like boundaries, culverts etc. are called offsets.
These are of two types:
(i) Perpendicular offsets at right angles to the chain line
(ii) oblique offsets not at right angles to the chain line
‘Ranging' is the process of
Theory of probability is applied to
Systematic errors are those errors