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
Correct Answer :
D. All the above
Related Questions
The point where a vertical line through the optical centre of the camera lens intersects the ground, is known as
Ground principal point
Ground plumb point
Iso-centre
Perspective centre
Longitudes are measured from 0° to
180° eastward
180° westward
180° east or westward
360° eastward
The net ground area of a vertical photograph 20 cm × 20 cm on scale 1 : 10,000 having overlaps 60% and 30%, is
0.50 sq km
0.56 sq km
0.60 sq km
0.64 sq km
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
Pick up the correct statement from the following:
The sun's right ascension increases for 0 h to 24 h when it returns to the First point of Aries
The maximum declination of the sun increases up to 23 ½° N on about 21st June
The minimum declination of the sun is zero' on 22nd September
All the above
Homologous points are
Opposite corners of a photograph
Nodal points of the camera lens
Corresponding points on the ground and photograph
Plumb points of stereo pair of photographs
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 method of surveying by triangulation was first introduced by the Dutchman Snell in
1600
1615
1630
1650
The true and mean suns occupy the same meridian at the same time on
April 15
June 14
September 1
All the above
The moon rotates round the earth once in every
29 days
29.35 days
29.53 days
30 days
The altitudes of a circumpolar star at culminations are 70° and 10°, both culminations being north of zenith. The declination of the star, is
80°
70°
60°
50°
With standard meridian as 82° 30' E the standard time at longitude 90° E is 8 h 30 m. The local mean time at the place will be
7 h 00 m
7 h 30 m
8 h 00 m
9 h 00 m
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 station pointer is generally used in
Triangulation surveying
Astronomical surveying
Hydrographical surveying
Photogrammetric surveying
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'
The coverage is least if photography is
High oblique
Low oblique
Vertical
None of these
In a truly vertical photograph,
Principal point coincides the isocenter
Iso-centre coincides the plumb point
Plumb point coincides the principal point
All the above
At western elongation, the pole star moves
Eastward
Westward
Northward
Southward
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
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 latitude of a place was obtained by subtracting the zenith distance of a star from its declination, the observed star was between
Horizon and equator
Equator and zenith
Zenith and pole
Pole and horizon
The First Point of Aeries
Is the point in the celestial sphere where zero meridian crosses the celestial equator
Is usually denoted by the Greek letter γ
Is located near the very conspicuous rectangle of stars in the constellations of Pegasus and Andromeda
All the above
The parallax equation Δp = BmΔh/H - h is applicable to entire overlap of the photographs only if parallax is measured
Normal to base line
Parallel to base line
Both (a) and (b)
Neither (a) nor (b)
The height displacement on a vertical photograph
Increases as the horizontal distance increases from the principal point
Increases as the ground elevation increases
Decreases as the flying height increases
All the above
α and β are the angles subtended by a point of elevation h at their air station with respective plumb points. Photo scale and focal length of the lens being S and f respectively. Parallax displacement of the point due to relief, is
h tan α/S
h tan β/S
h (tan α + tan β)/S
h (tan α - tan β)/S
The following points form a pair of homologous points:
Photo principal point and ground principal point
Photo isocenter and ground isocenter
Photo plumb point and ground plumb point
All the above
The angle between the direction of star and the direction of earth's axis of rotation is called
Co-declination
Co-latitude
Declination
Latitude
The zenith is the point on the celestial sphere
East of observer
West of observer
North of observer
South of observer
In field astronomy, the quantities observed are entirely
Lengths
Angles
Heights
All of these
If f is the focal length of the camera lens and θ is the angle of tilt, the distance of the plumb point from the principal point will be
f sin θ
f cos θ
f tan θ
f sec θ