The parallax of a point on the photograph is due to
Ground elevation
Flying height
Length of air base
All the above
Correct Answer :
D. All the above
Related Questions
If α is the observed altitude, the refraction correction in seconds, is
58 cot α
58 tan α
58 sin α
58 cos α
The negative sign is assigned to
Reduction to mean sea level
Correction for horizontal alignment
Correction for slope
All the above
The point where vertical line passing through the perspective centre intersects the plane of the photograph, is known as
Photo plumb point
Plumb point
Nadir point
Isocenter
The point on the photograph where bisector between the vertical line through optical centre of the camera lens and the plate perpendicular meets, is known as
Principal point
Isocenter
Plumb point
Perspective centre
On vertical photographs, height displacement is
Positive for points above datum
Negative for points below datum
Zero for points vertically below the air station
All the above
The point at which sun's declination changes from north to south, is known as
First point of Aeries
First point of Libra
Vernal Equinox
Both (b) and (d) of the above
The displacement of the pictured position of a point of h elevation on a vertical photograph taken with a camera of 30 cm focal length, from an altitude of 3000 m, is
4.4 mm
5.5 mm
6.5 mm
7.5 mm
Assuming human normal vision distance 25 cm, smallest measurable angle 20, and intraocular distance 6.5 cm, the smallest depth to be discerned is
0.1 mm
0.5 mm
1.00 mm
1.1 mm
The zenith is the point on the celestial sphere
East of observer
West of observer
North of observer
South of observer
The latitude (λ) of a place and the altitude (α) of the pole are related by
λ = α
λ = 90° - α
λ = α - 90°
λ = 180° - α
Pick up the in-correct statement from the following:
Apparent solar time is measured from the lower transit of the true sun
Mean solar time is measured from the lower transit of the mean sun
Sidereal time is measured from the lower transit of the first point of Aries
Sidereal time is measured from the upper transit of the first point of Aries
The declination and right ascension of the sun becomes 23° 27' S and 270° respectively on
March 21
June 21
September 21
December 22
Pick up the correct statement from the following:
The measured stereoscopic base of photographs is obtained by dividing the air base in metres by the mean scale of the photograph
The difference between the absolute parallax of two points depends upon the difference in their elevations
The line joining the principal point of a photograph and the transferred principal point of the adjoining photograph, is called stereoscopic base
All the above
For mapping any country
Geodetic triangulation of greatest possible sides and accuracy is carried out
Primary triangles are broken down into secondary triangles of somewhat lesser accuracy
Secondary triangles are further broken into third and fourth order triangles, the points of which are used for detail surveys
All the above
The scale of a tilted photograph of focal length f taken from an altitude H, along the plate parallel through principal point is
f/H sec θ
f sec θ/H
f/H
f/H cos ½θ
The coverage is least if photography is
High oblique
Low oblique
Vertical
None of these
The necessary geometrical condition for triangulation adjustment is:
The sum of the angles around a station should be 360°
The sum of the three angles of a plane triangle should be 180°
The sum of the eight angles of a braced quadrilateral should be 360°
All the above
At upper culmination, the pole star moves
Eastward
Westward
Northward
Southward
If the image of a triangulation station of R.L. 500 m is 4 cm from the principal point of a vertical photo taken from an altitude of 2000 m, above datum, the height displacement will be
2 mm
4 mm
6 mm
10 mm
An aerial photograph may be assumed as
Parallel projection
Orthogonal projection
Central projection
None of these
Stellar astronomy deals with
Plane surveying
Geodetic surveying
Star observations
Planet observations
Pick up the correct statement from the following:
Sidereal time at any instant is equal to the hour angle of the first point of Aries
Local sidereal time of any place is equal to the right ascension of its meridian
Sidereal time is equal to the right ascension of a star at its upper transit
All the above
The stereo plotting instruments are generally manufactured on the principle of
Optical projection
Optical mechanism projection
Mechanical projection
All the above
Pick up the correct statement for horizontal photographs.
Parallel lines do not appear parallel in central projection
The two sides of a road meet at the vanishing point
The lines parallel to the negative plane are projected as parallel lines
All the above
Pick up the incorrect statement from the following. In a spherical triangle
Every angle is less than two right angles
Sum of the three angles is equal to two right angles
Sum of the three angles less than six right angles and greater than two right angles
Sum of any two sides is greater than the third
The prime vertical passes through
The east point of the horizon
The west point of the horizon
The zenith point of the observer
All the above
The latitude of the observer's position, is
Elevation of the elevated pole
Declination of the observer's zenith
Angular distance along the observer's meridian between equator and the observer
All the above
A nautical mile is
One minute arc of the great circle passing through two points
One minute arc of the longitude
1855.109 m
All the above
The correction applied to the measured base of length L is
Tension = (P - Ps)L/AE
Sag = L3w²/24P² where w is the weight of tape/m
Slope = (h²/2L) + (h4/8L3) where h is height difference of end supports
All the above
While making astronomical observations, the observer is mainly concerned with
The direction of the vertical, the axis of rotation of the instrument
The direction of the poles of the celestial sphere
The direction of the star from the instrument
All the above