Tag Archives: surveying

Want To Take Photographs From An Elevated Position? Use This Photography!

Photographs From An Elevated Position

Aerial photography involves capturing photographs by using airborne cameras. In other words, it involves taking the photographs of the ground from a direct down position or elevated position. In this photography, the camera is not supported by any ground-based structure. In general, aerial photography is the method of taking pictures with a ‘bird’s eye’ view of the ground below from an airplane, or from a satellite or rocket and it is a common method of reconnoitering land features.

Aerial photography is widely used at the time of war to guide the intrusions through the land. Besides from the military operations, this photography also loosens the geological irregularities and can pinpoint the international boundaries in an easy manner with conviction. Aerial photography in India is offered by many aerial photography companies.

Benefits of Aerial Photography

This photography is suitable for studying the topography of a region. With this photography, the valleys, mountains, terrain and river systems are easily pictured. It helps to select the sites of important installations like hydroelectric power projects or irrigation channel. This type of photography is also used by real estate developers whose area of operation is usually very extensive. These aerial photographs are used for promotional works also.

Some of the Geological Survey companies have done amazing work with the help of aerial photography by classifying various areas based on terrain type, altitude, and the nature of sub-soil, resources and vegetation etc. In addition to this, this photography is used in GIS that deals with charts and maps. This photography also gives benefits to a number of state and federal governments while planning or relocating satellite townships as well as restructuring existing ones.

Also, natural calamities like flood, timber fire, earthquake, tornado and volcanic eruptions can be pictured or photographed with this aerial photography only. If such a condition happens, government make use of aerial photography to determine the scale of damage. This also used for space photographs. This photography is used as a method of landscape studies, particularly in researches and archaeology. Drone survey companies in India provide this type of services to the people. Photographs are taken in two different forms in aerial photography and both have different applications and uses. The two different forms of aerial photography are oblique and vertical.

Oblique

The oblique photographs are taken at an angle of 45 degrees. These photographs are taken manually at any degree and give the best view of a landscape. Images taken with oblique are generally used in archaeology to take a broad context of a feature and the area around it. These images are taken from small helicopters and fixed-wing aircraft and it is suitable for monitoring the erosion of monuments and features of many decades.

Vertical

This form involves taking photographs straight down over a landscape. This form is a plan view, therefore, it has no angle to distort the image. This form of aerial photography provides a good impression of the differences in the elevation of land and in this form the photographs are taken at regular heights. These images are used to generate Orthomosaic maps, Digital Elevation Models, Reflectance maps, etc

Contact Pigeon Innovative Solutions for Drone photography, Drone Survey, 3D Modelling, etc anywhere in India or world. Get your Quote now.

Contour lines generated using Aerial Drone Survey

What are Contour lines?

Contour lines are generated by connecting all the points of similar elevation together. These lines are drawn on a plan of a particular terrain to understand the nature of surface, identify cut fill volume, study water flow characteristics, estimate valley depth and steepness. Contour lines form a smooth curve of same elevation points. Contour lines are also called as isohypse,  isoline, isopleth, or isarithm.

contour lines generation using aerial drone survey
Figure: Contour line illustration

Contour maps are generated of Hill Ranges, Valleys, Mountains, Large lands, Agricultural fields, Farmlands, Forests, Archaeological sites, Water bodies, etc.

What does contour lines indicate?

  1. -: Widely spaced contour lines indicates flat terrain
  2. -: Closely spaced contour lines indicates steep terrain
  3. -: Irregular contour lines indicate uneven surface
  4. -: Concentric closed contour lines with increasing values towards center indicates a hill or elevated terrain
  5. -: Concentric closed contour lines with decreasing values towards center indicates a pond or water body
  6. -: Contour lines with U-shape convexity indicates ridge
  7. -: Contour lines with V-shaped convexity indicates valley
  8. -: When contour lines cross each other, it indicates existence of overhanging cliffs or a cave
  9. -: When contour lines are meeting in some portion, it indicates existence of a vertical cliff

 

What are the uses of Contour lines?

Contour lines are generally used to understand the terrain profile for multiple uses as follows:

  1. -: Depth of cutting and filling is decided from a contour map profile path, when desired level or elevation of road/railway is known
  2. -: Minimizing and balancing earthworks by deciding the routes of the railway, road, canal or sewer lines using contour lines
  3. -: Catchment area and quantity of water flow at any point of nalla or river is found out using contour lines
  4. -: In agricultural work, contours maps are useful as guide lines in planning of trees on hilly terrain and also land improvement project. In addition to this, drainage system is also conveniently planned with contour maps
  5. -: Initial feasibility study for Wind power or Solar Power project, for studying the terrain profile
  6. -: Initial feasibility study for Ropeway construction, a survey needs to be done to analyse the terrain for desired ropeway, cable car path
  7. -: Volumetric calculations are performed as required for extracting the volume of rocks, gravel of a mountain and estimate it’s total value. Hence, Effective Cost estimates is made available with the help of the contour maps
  8. -: Contour lines are also benificial for Mining companies especially for calculating the volume of stocks
  9. -: Archaeological surveyors are using contour lines to get insights about history

contour line generation

Figure: Contour line of small elevated area

How are contour lines made using Unmanned Aerial Vehicle (UAV) or Drone?

Drones are used to collect the data in the form of High quality images. The complete captured data is aligned by aerial triangulation. The aligned data is then ortho-rectified and georeferenced using the GCP information. Subsequently, the final Digital Elevation Model (DEM) and Contour lines at required elevation change are generated.

Want to carry out contour line survey at your site? Call Pigeonis at +91-9004329048 or rather just drop your requirements at contact@pigeonis.in