What is Photogrammetry? Everything you need to know about

Last Updated on August 29, 2022 by Admin

This article discusses Photogrammetry, its types, applications, and all you need to know about Photogrammetry surveying along with the career options for civil engineers.

The art of utilizing photos to scale and measure items is known as photogrammetry. In photogrammetry, you capture numerous images from various angles and combine them using specialized software to create a scaled 3D image or model. Then, using this model, a region that would be difficult or impossible to view otherwise, such as a cleared crime scene or construction site, is examined.

Topographic maps are typically produced using photogrammetry using aerial and spatial photography. At the School of Surveying, close-up photogrammetry is also utilized to produce virtual models of old buildings or to measure animals accurately for use in wildlife studies.

Triangulation is the essential idea of photogrammetry. So-called “lines of sight” from each camera to spots on the object can be generated by taking photos from at least two different angles.

Topographic mapping, architecture, engineering, manufacturing, quality control, police investigation, cultural heritage, and geology are just a few of the industries that use photogrammetry.

What is Photogrammetry?

With the use of software that can meet the individual needs of the user, the field of photogrammetry has experienced exponential growth. It is the finest choice for structural analysis and 3D representations of any site because of its small size and simplicity of use.

The adoption of photogrammetric techniques in a variety of fields has been made possible by the high precision measurements it provides along with the computing advantages. With increased digitization and the usage of sophisticated software, this is a developing technology that will experience countless improvements and adjustments.

Point placements would be accurate to 0.1mm at 68% probability on a 3m object at 1 part in 30,000. (One sigma). This is only roughly accurate. The project needs to be scaled and/or have control points established in order to determine absolute correctness. The absolute accuracy is then impacted by the precision of these scales and control points.

Aimé Laussedat (April 19, 1819 – March 18, 1907) was the first to create a topographic map using terrestrial pictures in 1849. The “Father of Photogrammetry” is the term used to describe him.

Using photographic images, patterns of electromagnetic radiant imaging, and other occurrences, photogrammetry is the science and technology of gathering accurate information about real-world objects and their surroundings.

Photogrammetry comes in a wide variety. The extraction of three-dimensional measurements from two-dimensional data (i.e., images) is one example. For instance, if the scale of the image is known, the distance between two points that are on a plane parallel to the photographic image plane can be determined by measuring their distance on the image.

Another is the exact color range and value extraction from pictures of materials to represent properties like albedo, specular reflection, metallicity, or ambient occlusion for physically-based rendering.

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Definition of Photogrameetry

As stated by the photogrammetry website the photogrammetry definition is “Photogrammetry is the science of making measurements from photographs.”

The meaning of photogrammetry is the input to photogrammetry is photographs, and the output is typically a map, a drawing, a measurement, or a 3D model of some real-world object or scene. Many of the maps we use today are created with photogrammetry and photographs taken from aircraft.”

Also, check the other definitions at;

• Wikipedia Photogrammetry
• Dictionary definition at Dictionary.com

Photogrammetry software

Photogrammetry software is a computer-aided design technique that uses optics to capture data about the surface of an object and then uses a mathematical model to convert this data into 3D geometry.

Photogrammetry is an open source process, which means that anyone can use it to create models of objects. This makes it a good option for creating models for use in video games, movies, and other types of media.

Android is a platform that is well-suited for photogrammetry applications. There are many different imaging apps available that can capture high-quality photos of your project. Once you have collected the necessary photos, you can use a software such as ZBrush or Maya to create a 3D model or renderings of your project.

With photogrammetry with drones, you can quickly create 3D models of your projects. Whether it’s the next frontier for your construction company or a new way to generate revenue for your real estate business, this process is a smart investment.

photogrammetry app lets you create 3D models easily by taking a series of photos in your environment, which the app then converts into a model.

Trnio, Scandy Pro, ‎3D Scanner App and Heges are some of the best photogrammetry apps.

Photogrammetry 3d scanning is a process of taking a series of photographs of an object and then using those photos to create a 3D model. This model can be used to create a realistic image of the object or to inspect it in detail.

Photogrammetry is often used to capture objects that are difficult or impossible to access, such as archaeological sites or sculptures.

Types of Photogrammetry

Depending on where the camera was pointed at the moment of the photo, there are basically two sorts of photos utilized in photogrammetry.

1. Terrestrial Photograph

Terrestrial photogrammetry is the branch of photogrammetry in which images are captured from a fixed location on or near the ground, and the image therefore captured is referred to as such. Terrestrial photographs are those that were taken from a fixed camera location on the ground or quite close to it.

A photo theodolite, which combines a camera and a theodolite, is used to take pictures. Using the tenet that “if the directions of the same items photographed from the two extremities of the measured base are known, their position can be found by the intersection of two rays to the same object.”

2. Aerial Photograph

Aerial photogrammetry is the branch of photogrammetry in which images are captured using a camera mounted on an airplane that is flying over the scene and the image is captured thereby. The following are some characteristics of aerial photos:

• Images captured by a camera mounted on an aerial vehicle
• Applied to the ground surface for a variety of purposes, mostly information extraction.
• The aerial cameras aboard the aerial vehicle are used to take aerial pictures (airplane for the purpose of photography)
• Applied to the ground surface for a variety of purposes, mostly information extraction.
• Photos are shot with the camera axis vertically or nearly vertically from a camera station in the air.
• This area of photogrammetry involves taking pictures from an aircraft.
• For huge objects, this is the best mapping technique currently available. It is also helpful for military intelligence.
• An aerial camera mounted on an airplane is utilized for this.

In aerial photogrammetry, there are two different kinds of photographs.

a. Vertical Photograph

These images were captured from the air with the camera axis vertical or nearly vertical. A photograph that is properly vertical resembles a map very much. These are used to compile engineering and topographic surveys on various scales.

b. Oblique Photograph

These images were captured from the air with the camera’s axis tilted away from vertical. A wider area of the ground is covered by an oblique shot, but the level of detail clarity decreases as the photograph gets further away. Oblique pictures can be further classified into two groups based on the obliquity angle.

i. Low oblique photographs:

Low oblique photography is defined as oblique photography that does not display the horizon. Typically, these images are used to create reconnaissance maps of inaccessible regions.

ii. High oblique photograph:

A high oblique photograph is an oblique image that is sufficiently inclined to reveal the horizon. In places with sparse ground control, such images were previously utilized to extend planimetric and height control.

Principle of photogrammetry

The following can be used to explain photogrammetry’s basic idea:

• The basic idea behind a photogrammetric survey is very similar to a plane table survey.
• The only distinction is that here, rather than in a plane table survey, the majority of the work is completed in an office.
• Rays are drawn with the central point of each photograph acting as a fixed station to obtain junction locations that resemble those found in a plane table.
• Is appropriate for engineering or topographical surveys as well as projects requiring greater accuracy.
• Due to the difficulty in distinguishing spots on the two images, it is inappropriate for areas of dense forest and other environments.

Advantages of Photogrammetry

A few of the benefits that photogrammetry has over conventional techniques are listed below:

• The ease and speed with which data can be gathered are photogrammetry’s main benefits. With the aid of UAV, UAS, or satellite imaging, photogrammetry can assist in taking pictures, analyzing the data to obtain measurements, and quickly and cheaply turning them into 3D maps.
• The findings produced by photogrammetric techniques are quite accurate, making it very trustworthy to use for mapping or other applications.
• By utilizing both topological and cultural elements of the land surface, it provides a wide or broad view of the mapped area. This makes it possible for other investigations to utilize related data more effectively.
• The information that is gathered is accurate, and permanent, and chronicles the state of affairs in both pictorial and metric forms at the moment the images were taken.
• Since the information gathered is permanent, it is much simpler to revisit or re-evaluate the site to obtain any missing data without wasting any time.
• Using UAV, UAS, or satellite images photogrammetry, it is simple to take photos of remote sites and challenging-to-reach places with precision in dimensions. The crew’s security while surveying potentially hazardous areas is also less at risk as a result of this.
• Photogrammetry can be used to survey roads without jeopardizing the crew’s safety or obstructing traffic flow. Photos and measurements can be taken without obstructing traffic. The road’s characteristics can be utilized to plan for upcoming projects once they have been recorded.

Disadvantages of Photogrammetry

The following is a list of drawbacks related to the use of photogrammetry:

• The primary drawback is that there must be light for the photogrammetric survey to be successful. It cannot project its own light source, which makes it challenging to capture pictures when the light source is dim.
• It cannot be used for precise measurements when visibility is restricted in the vicinity, which can be brought on by climatic events like snowfall or rain. The accuracy of the measurement is not achievable if there is vegetation or a tree canopy that can obstruct the camera’s line of sight.
• The flying height has a significant impact on how accurate the measurements are.
• Because photogrammetry surveys are digital, they are vulnerable to viruses and hacking attacks that result in data loss.

Applications of Photogrammetry

The following list of photogrammetry applications includes the following:

• Mapping: Using photographs acquired with UAVs, drones, UAS, or satellites, photogrammetry is used to map terrains. With great precision and a much quicker return time, it offers photos in high resolution. An accurate image of the terrain can be obtained via photogrammetry through the use of both vertical and oblique images, which aid in the creation of 3D maps of an area. Due to the availability of aerial photography, it is now simple to map the terrain, including submerged terrains, in previously inaccessible places.
• Civil Engineering: Photogrammetric techniques provide in-depth information on the topography of the ground surface, which is crucial for this field. The region can be accurately designed with the use of pictures and a 3D depiction. Planning for urban growth is aided by photogrammetric maps. It is vital to have a thorough understanding of the topography so that the roads and tracks may be properly planned for easier and proper transit.
• Geology: Soil kinds and strata can be identified extremely effectively using photogrammetry. It is feasible to comprehend the shape, formation, and composition of rocks using the point cloud image produced by photogrammetry. Photogrammetry is frequently used to measure the depth and volume of lakes and rivers. The research on vegetation and forest thickness is also done using it in forestry.
• Archaeology: Using old photographs to map a space and gain an understanding of the buildings and layout of an archaeological site, photogrammetry presents a singular opportunity. At excavation sites, overhead photography is frequently used to map surface remains. Compared to conventional approaches, photogrammetry makes documenting maritime archaeology incredibly simple.
• Medicine: Up close in biomedical research as well as the diagnosis and treatment of some ailments, photogrammetry is frequently employed. This method is generally used to measure the contour of the face, the body, and to capture motions for measurements of the back, torso, and face surface.
• Non-topographic Use: Photogrammetry has been extensively used in non-topographic ways in the field of medical study. In order to increase accuracy, it is widely utilized in radiography, as well as in procedures like neurosurgery, sinus surgery, plastic surgery, and rehabilitation. When doing procedures that are difficult owing to the site’s location or any further development, such as tumors, photogrammetry can be very beneficial. The surgeons can arrange the strategy of the surgery with the aid of 3D modeling of the growth in relation to the nerves, muscles, and other organs.
• Using photogrammetric photographs enables a three-dimensional investigation of the palate and its alterations during rapid palatal expansion and helps to comprehend the obtained dental movement.
• Structural Engineering: Photogrammetry is used in structural engineering to monitor huge structures. Utilizing this technique becomes helpful since an infinite number of points can be taken into account for measurements and processed instantly automatically. Photogrammetry is preferred since it has complete packing that allows you to capture photos and then automatically map them out on a 3D image with accurate images. It is a desirable option for use in structural engineering and monitoring because of its simple operation, compact design, and ability to capture photos in any setting and at any angle. With the high level of precision that photogrammetric methods and 3D representations provide, it is now much simpler to analyze a site and evaluate a construction project step-by-step. Options for photogrammetry also enable projection of the expected outcome after construction is finished.
• Sports: The sports sector now has access to a new degree of accuracy thanks to photogrammetric techniques. This is particularly relevant to sports and leisure activities that rely on maps. The accuracy of the terrain maps is essential to many sports, including biking, climbing, trekking, and cross-country rallies. Players can very accurately plan their approach using photogrammetry terrain maps to provide them a better understanding of the difficulties and variety of the terrains they will be racing on. In a virtual training system, photogrammetry has recently been used in sports. Photogrammetry is employed in this case to track the body’s movements and may capture even the smallest change in body position, allowing them to spot mistakes and vastly enhance their performance.
• Film making and entertainment: With the advent of technology, filmmaking has undergone a significant transformation. We watch movies with incredible animatronics that we could never have thought were conceivable. The creation of precise 3D models using photogrammetry allows directors the option to construct their own sets. The ability of photogrammetry to obtain highly accurate proportions has aided in the production of realistic surroundings. This aspect of photogrammetry is now widely used in constructing virtual settings for games, creating circumstances that are more photorealistic to enhance the experience.
• Real estate: It is impossible to ignore the boom in this industry. The real estate sector has been forced to adopt the most recent technologies to sell and present the eye-catching aesthetics of their properties due to the intense competition in the market. Real estate brokers are able to obtain images taken from various perspectives with the highest precision in a short amount of time with the aid of drones and photogrammetric techniques. It is an economical way to provide the buyer the chance to see and decide.
• Forensics: Because the measures are quick and precise Forensic sciences and research have a huge potential for using photogrammetry. It is widely employed in cases of unintentional harm and traffic accidents where it is crucial to know even the smallest details. The precise measurements that are documented by photogrammetry are useful and recognized in legal proceedings.

Photogrammetry vs Lidar

There are two main types of technology used to create 3D models: Photogrammetry and lidar . There is a lot of debate between photogrammetry and lidar when it comes to mapping objects.

Photogrammetry is a more traditional method that uses images taken by a camera to create a 3D model. Lidar is a newer technology that uses lasers to create a detailed 3D model.

While both methods have their benefits, photogrammetry is usually faster and more accurate than lidar.

Photogrammetry is a technique that uses photos to create 3D models. Lidar, on the other hand, uses lasers to measure distances. Both techniques have their advantages and disadvantages.

Photogrammetry is cheaper than lidar, but it can be more time consuming. Lidar can be more accurate, but it can also be more expensive. It all comes down to what you are trying to achieve with the map.

Job description of Photogrammetry Surveying specialist

If you’re interested photogrammetry jobs and want to bewcome a photogrammetry specialist, there are a few things you need to know.

First, you’ll need to have a good camera that can take high-quality images. Second, you’ll need to be skilled at using software to create 3D models from those images.

Third, you’ll need to have a lot of patience – setting up the shot, waiting for the software to process it, and then looking at the results can take hours or even days. But if you have the right skills and the right equipment, it could be the perfect career for you!

The duties of a Surveyor Photogrammetric include:

• Preparing topographical and project maps from aerial images of the area by calculating the longitude and latitude of a number of points on the ground using the triangulation or traverse method.
• Joining photos in the right order, aligning features, and pointing out specifics and information like place names, river names, railroad tracks, administrative boundaries, and other verification data to obtain a continuous picture of the area taken.
• Using stereoscopes to identify control points and verifying points on the ground if images do not clearly show them due to scale differences between points, distortions, or other factors.
• Reducing the size of a photograph by employing graphical techniques or photogrammetric equipment.

Key Competencies required to become a Photogrammetry Surveying specialist

A photogrammetry surveying specialist can benefit from having the following core competencies:

• Competent in geographic information systems, remote sensing, photogrammetry, cartography, and mapping.
• Knowledgeable about a variety of field concepts, methods, and procedures
• Knowledgeable in GPS surveying, site surveys, photogrammetric profiling, digital photogrammetry, and total station
• Skilled at range finding, picture modeler, and photo mapping
• Ability to perform basic mathematical calculations, perform analytical computations, and comprehend coordinate geometry
• The capacity to conduct surveys using ICT
• Comprehend and interpret engineering and construction drawings, and set forth basic construction components.
• Be familiar with how to use coordinate systems, grids, and map projections.

Learn more in this photogrammetry ppt

Download the photogrammetry surveying pdf notes.

Salary details of Photogrammetry Surveying Specialist

Photogrammetry is a field of photography that uses digital images to create three-dimensional models from photographs.

People who work in this field typically have a degree in photojournalism or graphic design. They use software to take pictures of objects and then use computer software to create a model of the object. The models can be used for commercial or personal purposes.

Photogrammetry is a growing field, and there are many opportunities for people who want to work in it. Many companies hire photogrammetrists to create models for product design, marketing, and advertising.

There are also many freelance opportunities available, and people can start their own business if they have the necessary skills and equipment.

These photogrammetry surveyors typically work in the following fields:

• Topography institutes and research organizations throughout India
• Indian service providers of photogrammetry
• Firms providing architectural, engineering, and related services
• Local administration
• Businesses offering management, scientific, and technical consulting services
• Self-employed

Median salary for Photogrammetry professional is $46,910 per year

Cartographers and photogrammetrists collect, measure, and interpret geographic information in order to create and update maps and charts for regional planning, education, and other purposes.

The Cartographers and Photogrammetrists salary in US is $68,900 per year

Specialists in photogrammetry surveying are paid mostly based on their talents, abilities, and years of experience.

• For applicants with up to two years of experience, a monthly salary of INR 23,500 to INR 24,500 in India.
• For applicants with two to five years of experience, 36,000 to 37,000 Indian rupees a month
• INR 45,000 to INR 46,000 per month for those with more than 5 years of experience.

Conclusion

In all scientific domains, photogrammetry has greatly facilitated and simplified life. Photogrammetry has a few drawbacks, but individuals are utilizing it to its fullest potential thanks to partnerships with cutting-edge software and technology.

Engineers can reduce the cost of unused materials by having more precise measurements. Due to the software program doing the majority of the scaling work, businesses should also be able to cut labor expenditures. Photogrammetry and civil engineering work hand in hand. Photogrammetry greatly simplifies and improves the effectiveness of this work for the variety of tasks necessary in this industry.