Put yourselves in the shoes of a civil engineer. You\u2019re given 1500 acres of land and are tasked with chalking out a detailed blueprint of the various structures and facilities that need to be set up in order to construct a university campus right beside the coast. Naturally, one of the first steps that must be carried out is to measure not just the dimensions of the land but also its topography and several other features. This process of mapping out a given region is known as surveying. <\/p>\n\n\n\n
While surveying through conventional physical methods may be feasible for small scale projects, it is not practical to do so on a large scale. For example, a city planner cannot possibly go around measuring the entire city and all its structures before creating a plan for a new transport system. The best possible solution is to remotely gather all measurements needed to chalk out a plan and that is where photogrammetry<\/em> comes in. <\/p>\n\n\n\n It is the science of obtaining reliable information about the properties of surfaces and objects without physical contact with the objects, and of measuring and interpreting this information. Naturally, this field goes hand in hand with remote sensing, the process of detecting physical characteristics from a distance.<\/p>\n\n\n\n It is a combination of three Greek words \u2013 phos <\/em>or phot <\/em>meaning light, gramma <\/em>which means letter or something drawn and metrein<\/em> which means measure. <\/p>\n\n\n\n Photogrammetry finds applications in various fields like military, surveying, engineering and even forensics and medicine primarily to map out certain areas and regions accurately by taking a series of photographs aerially and combining them to generate maps and 3D renders (used by Google Earth) to scale, thereby assisting planning and visualization.<\/p>\n\n\n\n There are two main types of photogrammetry \u2013 Metric (used to precisely determine size, shape, coordinates and other features) and Interpretive (helps recognize and identify photographic features thereby adding intelligence to the information visible in the frame). <\/p>\n\n\n\n Naturally, the first step would be to acquire the data (pictures of concerned region) needed as inputs that need to be processed to produce the desired output (map\/3D renders). This could be something as large as the map of a city to a building or even a particular organ in the body to analyze them without invasive procedures. <\/p>\n\n\n\n Thus, a photographic device is strapped to aerial vehicles that hovers over the region that needs to be mapped and takes a series of photographs. From these, the following data are generally received: <\/p>\n\n\n\n In order to digitize physical objects, photogrammetry has to measure and record two distinct attributes. <\/p>\n\n\n\n To assess the position, a series of pictures (a minimum of two is necessary but typically dozens up to a few hundred are captures) from different angles is needed to gather spatial information. Algorithms compare different image segments and their relative movements to each other from picture to picture. A good analogy for this process is how humans perceive depth of various other objects based on how they move relative to one another. <\/p>\n\n\n\n Through computation, these series of images are combined to produce a single, coherent map or model of the region. Maps too can be of various types \u2013 Planimetric maps only contain the horizontal position of ground features whereas topographic maps factor in elevation as well. Thematic maps can be used to emphasize particular features like all the water bodies and channels in a region. <\/p>\n\n\n\n While photogrammetry is a concept that primarily finds use in engineering, it has several interesting applications as well. They can play a crucial role in set design and the 3D renders help visualize and plan worlds different from our own for movies and video games. In fact, famous movies like The Matrix and Fight Club relied on photogrammetry for set design. <\/p>\n\n\n\n They play a key role in military intelligence by geo-surveying an unknown region very quickly and helping the troops understand what to expect ahead. <\/p>\n\n\n\n Advances in tools for optical detection as well as computational progress have fueled the precision of photogrammetry. In fact, it finds use in the sports industry where athletes can use it for training by capturing the tiniest of details such as the angle of shoulder orientation which can help fine tune an athlete\u2019s performance. <\/p>\n\n\n\n A little further away in the forensics industry, photogrammetry can help map the crime scene and photogrammetry experts can help interpret these models to great precision and determine what was physically possible which is particularly helpful in cases involving traffic accidents and accidental injuries.\u00a0<\/p>\n\n\n\n – By Ankit Sandeep, Third Year Department of Civil Engineering<\/em><\/p>\n","protected":false},"excerpt":{"rendered":" Put yourselves in the shoes of a civil engineer. You\u2019re given 1500 acres of land and are tasked with chalking out a detailed blueprint of the various structures and facilities that need to be set up in order to construct a university campus right beside the coast. Naturally, one of the first steps that must…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[10,27],"tags":[],"class_list":["post-1100","post","type-post","status-publish","format-standard","hentry","category-tech","category-yantrika"],"_links":{"self":[{"href":"https:\/\/nitk.acm.org\/blog\/wp-json\/wp\/v2\/posts\/1100","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nitk.acm.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nitk.acm.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nitk.acm.org\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/nitk.acm.org\/blog\/wp-json\/wp\/v2\/comments?post=1100"}],"version-history":[{"count":1,"href":"https:\/\/nitk.acm.org\/blog\/wp-json\/wp\/v2\/posts\/1100\/revisions"}],"predecessor-version":[{"id":1101,"href":"https:\/\/nitk.acm.org\/blog\/wp-json\/wp\/v2\/posts\/1100\/revisions\/1101"}],"wp:attachment":[{"href":"https:\/\/nitk.acm.org\/blog\/wp-json\/wp\/v2\/media?parent=1100"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nitk.acm.org\/blog\/wp-json\/wp\/v2\/categories?post=1100"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nitk.acm.org\/blog\/wp-json\/wp\/v2\/tags?post=1100"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}What exactly is photogrammetry? <\/strong><\/h4>\n\n\n\n
How does photogrammetry work?<\/strong><\/h4>\n\n\n\n
Applications of Photogrammetry:<\/strong><\/h4>\n\n\n\n