What Is Photogrammetry?

Photogrammetry combines science and technology to gather information from images about the physical environment and objects in it. To accomplish this, photogrammetry technology employs a process of recording, measuring, and interpreting different types of photographic imagery, some of radiation and others of objects. Essentially, through this process, you or your business could construct three-dimensional (3D) models from two-dimensional (2D) photographs. Artificial intelligence (AI) technology can be used to enhance the process by identifying certain objects and by cleverly noticing changes over time, as well as alterations in light. 

You might use photogrammetry for various purposes and across various industries to map results and find specific information. Some of the industries that use photogrammetry include the automotive industry, oil and gas, wind energy, underwater applications, and mining. 

In this article, you’ll learn more about what photogrammetry is, what it’s used for, and who applies it, and the benefits of using this technology.

What is photogrammetry?

This process involves using 2D photos to create accurate 3D models. You extract information from photos by gathering data about the positions of objects using the vantage points of two different views to create and measure depth and perspective, similar to how human eyes work. For modeling purposes, you may also use photogrammetry to extract color information and properties from photos.

You can break down the word photogrammetry into “photo,” which refers to light, “gram,” which means drawing, and “metry,” which means to measure. Considering these three parts of the word photogrammetry, you can see that they explain the process behind the word, which is to take measurements from a photograph.

Types of photogrammetry

You’ll find three main types of photogrammetry—aerial, terrestrial, and space—based on where you position the camera when taking a photo. Let’s look at each in more detail.

Aerial photogrammetry

Aerial photogrammetry involves taking a series of photos of an area from the sky via an aircraft or drone, with a camera pointing straight down. To accomplish this, you position the camera to take multiple photos along the flight path, each overlapping, and then process using a stereo plotter. A stereo plotter lets you see two photos simultaneously in stereo view, which you can use to make a digital model.

Terrestrial photogrammetry

Terrestrial photogrammetry, in contrast to aerial photogrammetry, uses photos taken at ground level. You place the camera on a horizontal axis, taking multiple photos and recording the coordinates for analysis. This option is more accessible than aerial photogrammetry, as it doesn’t involve using an aircraft, and you can use normal cameras. However, professionals often use a theodolite to measure angles effectively. This optical device contains a mounted telescope capable of measuring angles with a phenomenal degree of precision.

Space photogrammetry

Space photogrammetry takes the process to another level by positioning a camera on a satellite or even on the moon to capture Earth. You might use this to understand more about the environment and the position of planets in space. Doing this can also help you learn more about cloud patterns on Earth while constructing a more accurate map of the planet’s surface.

Who uses photogrammetry?

Photogrammetry is commonly used to create scaled maps and 3D models of areas. Your company might use these to understand the terrain, analyze costs, and make accurate decisions. Various industries utilize this technology, from surveyors to mining to the oil and gas industry. Each industry uses photogrammetry for a different purpose. 

Construction

If this is your profession, you know that surveying land in the construction industry is time-consuming and expensive because teams of surveyors must take photos of an area and then sync those photos using triangulation before development even takes place. With photogrammetry, you can use a single drone to take photos from the air to determine the condition of the building site, and you can accomplish this in hours with less cost. 

Real estate 

Real estate companies use aerial photogrammetry to give customers a visual tour of a property from above. If you’re a realtor, you can even combine photogrammetry with virtual reality to offer tours inside buildings. 

Engineering

Similar to surveying, if you work in civil engineering, you may use photogrammetry to understand structures, buildings, and land that’s due for development. This allows for minimizing mistakes and an in-depth understanding of potential risks. 

Forensics

Forensics teams use photogrammetry to recreate crime scenes, giving them vital measurables such as the height of a suspect and the direction a bullet came from. Additionally, if you’re a detective, photogrammetry provides you with a digital copy of the crime scene, which means you can review it in its original state while investigating the case. 

Oil and gas

The oil and gas industry benefits from photogrammetry as it provides them with an aerial view of pipelines and allows workers to spot any potential risks. Also, aerial photogrammetry can detect leaks if you’re concerned with structural issues with pipelines. 

Sports

Sports teams and coaches use photogrammetry to improve their game by monitoring players' movements on the field and using this to build training systems. Also, if you’re an athlete who enjoys hiking or skiing, photogrammetry can contribute to topographical maps, which may help you anticipate difficult terrain. 

Photogrammetry tools

Photogrammetry utilizes various software tools to create your 3D models, including PIX4D, Autodesk ReCap, Meshroom, and Elcovision 10. Once you have taken your photos, these programs analyze them and use the information to reconstruct a 3D model for you.

Let’s take a look at some popular options.

PIX4D: This builds 3D models with the information taken from your images. Designed for professionals, this tool is highly effective, time-saving, and easy to use.

Autodesk ReCap: With this software, you can create 3D models of objects for use in construction, architectural, and engineering projects. By basing models on real-world objects, you can learn more about the present condition of these objects, which allows you to make better decisions.

Meshroom: If you’re a beginner, Meshroom is a great software option because it’s free and very intuitive. You can use this to calculate image measurements to build your 3D models. 

Elcovision 10: Elcovision 10 is fully automated software, and it’s popular because of its accuracy in producing automated, freehand drawings that equal laser technology. 

Benefits and limitations of photogrammetry

Depending on what you’re using it for, you’ll find several benefits that come with choosing photogrammetry for your project and some potential drawbacks compared to other options.

Benefits of photogrammetry:

Photogrammetry can be cost-effective. You need cameras, but these don’t have to be expensive models. Additionally, if you have a smaller budget, much of the software is inexpensive, with free options available.

• The versatility of photogrammetry means you can apply it to various industries, from construction to forensics and even to sports.

• You can use photogrammetry anywhere if you have a camera or a drone, meaning that your approach is, as is how much you use the technology. 

• Because drones feature the option to automate, you can take vast amounts of photos, increasing the overall effectiveness of the photogrammetry process.

Limitations of photogrammetry: 

• Based on the intricacy of the object and how many images you captured, reconstructing a 3D model of it using photogrammetry will likely take a considerable stretch of time. It can be a considerable drawback, particularly when facing a deadline.

• External conditions, such as bad lighting or adverse weather, might affect the quality of the photos and, thus, the overall photogrammetry process.

How to start a career in photogrammetry

If you’re interested in a career using photogrammetry, a photogrammetrist is a good choice. In this profession, you would most likely collect geographic data and then analyze it to design unique maps for various purposes. If you like maps, photography, and studying different landscapes, this might be a great job for you to pursue. According to Glassdoor, while working in this career, you could earn an average annual salary of $82,753 [1].

To become a photogrammetrist, you’ll likely need to earn a bachelor’s degree in one of the following majors: geography, surveying, geomatics, or cartography. Additionally, you’ll want to gain experience in various tools such as online mapping, remote sensing, light-image detection, and image processing. Finally, to implement the aforementioned tools, you’ll want to understand the software that runs them. Internships while in college can also provide valuable experience and help you acquire this knowledge.

Getting started with Coursera

Continue learning about photogrammetry and creativity with online courses. For example, you might like Artificial Creativity, offered by Parsons on Coursera. Throughout the course, you’ll learn about the possibilities for using AI to enhance real-life experiences and gain an understanding of the theories behind artificial creativity.