The normal longitudinal overlap is generally kept
50 %
60 %
70 %
75 %
Correct Answer :
B. 60 %
Related Questions
The angle between the observer's meridian and declination circle of a heavenly body, is known as
Hour angle
Azimuth
Right ascension
Declination
The coverage is least if photography is
High oblique
Low oblique
Vertical
None of these
The relation between the air base (B), photographic base (b), flying height (H) and the focal length (f) of a vertical photograph, is
B = bH/f
B =f/bH
B = b/fH
B = H/bf
The declination and right ascension of the sun becomes 23° 27' S and 270° respectively on
March 21
June 21
September 21
December 22
The principal line is the line joining the principal point and
Nadir
Isocenter
Perspective centre
None of these
For plane ground the scale of a vertical photograph will be same as that of a tiled photograph along the photo parallel through
Isocenter
Plumb point
Principal point
None of these
The stereo plotting instruments are generally manufactured on the principle of
Optical projection
Optical mechanism projection
Mechanical projection
All the above
Pick up the incorrect statement from the following. The angular distance of heavenly bodies on observer's meridian measured from the pole, is
Co-declination
Co-altitude
Co-latitude
Polar distance
In a tropical year, the numbers of sidereal days are
One less than mean solar days
One more than mean solar days
Equal to mean solar days
None of these
The point on the celestial sphere vertically below the observer's position, is called
Zenith
Celestial point
Nadir
Pole
Invar tapes used for measuring base lines, is made of nickel-iron alloy containing nickel
24 %
36 %
40 %
60 %
The angle between the plane of the equator and the plane of the ecliptic, is known as obliquity of the ecliptic and its value is
22° 30'
23° 27'
23° 30'
24° 0'
If δ is the declination of the Polaris and λ is the latitude of the place, the azimuth of the Polaris, is
cos δ/cos λ
cos (90° - δ)/cos (90° - λ)
sin (90° - δ)/sin (90° - λ)
tan (90° + δ)/tan (90° + λ)
Triangulation surveys are carried out for locating
Control points for surveys of large areas
Control points for photogrammetric surveys
Engineering works, i.e. terminal points of long tunnels, bridge abutments, etc.
All the above
Pick up the correct statement from the following:
The principal point coincides with plumb point on a true vertical photograph
The top of a hill appears on a truly vertical photograph at greater distance than its bottom from the principal point
The top of a hill is represented on a vertical photograph at larger scale than the area of a nearby valley
All the above
To have greatest coverage of the area, the type of photography used, is
High oblique
Low oblique
Vertical
None of these
Pick up the incorrect statement from the following:
Latitudes north of the equator are taken as positive
Latitudes south of the equator are taken as negative
Longitudes east of Greenwich are taken as negative
Longitudes west of Greenwich are taken as positive
The difference of parallax for a given difference in elevation is independent of
Focal length of the camera
Overall size of the photo graphs
Percentage of overlap
All the above
The hour angle of the heavenly body for Greenwich meridian equals the hour angle of the body for any other meridian + longitude:
Mean sun
True sun
Vernal equinox
All the above
The maximum error in radial line assumption, is
h/H f tan θ
h/H f² tan θ
h/H f² sin θ
h/H f cos θ
The nautical mile is the length of
1 minute of latitude
1 minute of longitude
1 degree of latitude
1 degree of longitude
Circumpolar stars
Rotate round the North Pole
Rotate round the celestial pole
Remain always above the horizon
Are seldom seen near the pole star
Equation of time which is the difference between apparent solar time and mean solar time at any instant, vanishes during one year
Once
Twice
Thrice
Four times
The great circle along which the sun appears to trace on the celestial sphere with earth as centre during the year, is called
Equator
Celestial equator
Ecliptic
None of these
The foot of the perpendicular on the picture plane through the optical centre of the camera lens, is known as
Isocenter
Principal point
Perspective centre
Plumb line
Homologous point is
Photo principal point
Ground principal point
Ground isocenter
All the above
The altitudes of a circumpolar star at culminations are 70° and 10°, both culminations being north of zenith. The latitude of the place, is
80°
70°
60°
40°
At lower culmination, the pole star moves
Eastward
Westward
Northward
Southward
Pick up the correct statement from the following. The difference between the longitudes of the places is obtained.
By subtracting their longitudes if places are in the same hemisphere
By adding their longitudes if places are in the different hemispheres
By subtracting the sum of their longitudes exceeding 180° from 360° if places are in different hemispheres
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