Editorial, Geoinfor Geostat An Overview Vol: 8 Issue: 3

Photogrammetry is used in surveying and mapping by using photography

Niharika Dvivedi^*

Department of Geography, University of Andra, India

*Corresponding Author: Niharika Dvivedi
Department of Geography, University of Andra, India
E-mail: niharikadvivedi@gmail.com

Received: July 10, 2020 Accepted: July 20, 2020 Published: July 27, 2020

Citation: Niharika (2020) Photogrammetry is used in surveying and mapping by using photography. Geoinfor Geostat: An Overview 8:3. doi: 10.37532/gigs.2020.8(3).261

Abstract

Keywords: 3D modelling, Photogrammetry, Picometre, Panoramas

Photogrammetry is used in surveying and mapping by using photography. In order to measure distance between any objects we can use photogrammetry. By using photogrammetry software’s, we can create 3d renderings with the help of images captured. During early days it is mostly used for topographic mappings but now a day it is been used in several number of other ways. It is the first remote sensing technology used to determine the geometric properties about objects using photographic images. The basic principle of photogrammetry is triangulation. Taking photographs from minimum two different locations that is line of sight can be developed from each camera to points on objects.

Types of photogrammetry: photogrammetry are of two types.
They are aerial photogrammetry, terrestrial photogrammetry.

Aerial photogrammetry: it is often used in topographical mappings with the help of digital photographs or video recorded from a a camera fixed on the bottom of an aircraft or any other flying objects. There are several numbers of platforms for aerial photogrammetry like fixed wing aircrafts, balloons, helicopters, rockets, drones etc. There are some types of aerial photographs like oblique, vertical, combination and orthophotos. In oblique aerial photography, the photographs are captured at an angle.if they are taken from low angle to earth surface then they are called as low oblique and if the photographs taken from a high angle then they are called high or steep oblique Vertical: the photographs captured straight down are called as vertical photographs. These photographs mainly used in photogrammetry and image interpretation. For photogrammetry pictures are captured with special large format cameras with standard and documented geometric properties

Combinations: depending upon purposes aerial photographs are combined.it can be done in many ways like panoramas, stereo photography, picometre etc. panoramas can be made by combining several photographs captured in different angle from one spot or from different spots at the same angle. Treo photography technique helps to create3d images from several photographs taken from different spots of the same area.in picometre five fixed mounted cameras provides one vertical and four low oblique photograph that can be used together. orthophotos: orthophotos are created by using vertical photographs.it is also known as orthophoto maps. the photographs which have been corrected geometrically can be unable as a map. Orthophoto is a simulation of a photograph taken from an infinite distance looking straight down to nadir. Depending on terrain corrections on a particular part of image, multiple geometric transformation are applied.in geographic information systems orthophotos are commonly used by the mapping agencies to create maps.in online map system such as google maps, large set of orthophotos, derived from different sources and divided into tiles are used.to simulate 3d landscapes orthophotos or satellite imagery overlays onto a digital elevation model by google earth. Aerial video: aerial video can be used for understanding scene and object tracking. The input video is recorded by low flying aerial platforms.

Terrestrial photogrammetry: it is also called as close-range photogrammetry. Terrestrial photogrammetry is one of the important branches of the science of photogrammetry.in this photogrammetry it deals with the photographs taken with cameras located on the surface of the earth either by handheld cameras or fixed to tripods or any other specially designed mounts. The principle of terrestrial photogrammetry is similar to that of plane table surveying

Applications

Photogrammetry is used in fields such as topographic mapping, architecture, engineering, manufacturing, quality control, police investigation, cultural heritage, and geology

In order to produce plans of large or complex sites quickly this is used by archaeologists. when objective weather data cannot be obtained, meteorologists use it to determine the wind speed of tornados.it is also used in movies post production to combine live action with computer generated imagery

Photogrammetry is increasingly being used in maritime archaeology because of the relative ease of mapping sites compared to traditional methods, allowing the creation of 3D maps which can be rendered in virtual reality.

3D modelling

A somewhat similar application is the scanning of objects to
automatically make 3D models of them. The produced model often. still contains gaps, so additional clean-up with software like MeshLab, net fib or Mesh Mixer is often still necessary. Google Earth uses photogrammetry to create 3D imagery