What is Drone Photogrammetry? (Explained for Beginners)

Drones nowadays come with impressive cameras that take crisp footage. So why not use that capability to earn some money? Like taking photos for photogrammetry applications.

Drone photogrammetry is a means of obtaining aerial photos of a difficult-to-measure space in conventional ways. You use software to process images and get exact measurements of the space or objects within.

However, not all camera drones are proper for photogrammetry. They need to meet some requirements we will discuss in this article.

But first, we’ll explain how drone photogrammetry works, its minimum requirements, benefits, downsides, and the industries where it’s useful.

How does drone photogrammetry work? #

Drone photogrammetry is when a drone reaches a specific altitude where its camera can take stable images.

Then the drone’s camera takes many pictures of a zone from that height and different angles.

The idea is to gather the required photos to recreate a 2D surface or a 3D model of the zone by overlapping those images.

Overlapping the images isn’t the drone’s job but specialized software.

This software recreates the 2D surface or 3D model with such exactitude that its operator can obtain distances, areas, and volumes of any location, object, or structure in that surface or model.

Why is drone photogrammetry so popular? – Benefits #

Before camera drones, taking the required photos of a zone of study was ineffective, inaccurate, pricy, and unsafe.

Companies needed dedicated individuals to move around and find the best spot to capture photos.

This way of gathering data takes lots of time. If any shot isn’t right, the person has to go to the same location and take the pictures again.

But how is the person sure the new photos are from the exact angle, height, and position?

It’s hard to tell unless the person uses a GPS. Drones know their location as they work with GNSS, so they can return to that spot and take an identical photo.

Another important fact is the altitude. Drones can fly up to 400 feet in geofenced areas, maintaining that altitude while moving comfortably in the air. This attribute helps in getting accurate shots.

You can also get the same pictures in an airplane or helicopter.

However, the aircraft requires the necessary equipment that costs thousands of dollars. The company providing the service must pay the pilot and the aircraft gas, which is expensive.

An hour of aerial photography is over $1,000.

Drone rates are cheaper than that. You can read the article in this link about the standard rates for drone photography.

An example #

To make an employee climb to a high altitude is a high risk, whatever the method and means to maintain that person’s safety.

Let’s say you must inspect a communication tower.

You first prepare yourself with the safety equipment, think about how you will get to that altitude, and how to inspect it in uncomfortable conditions.

All these actions are time-consuming and could cause you to make bad decisions that lead to inaccuracy.

A drone can climb to that altitude easily, maintaining its position while you control the camera gimbal from a safe distance.

Ultimately, drones simplified the aerial photography industry, making it accessible and fast.

Is there a downside to drone photogrammetry? #

However, drones have their flaws too.

According to the manufacturers’ manuals, drones for photogrammetry have a max flying time of between 40 and 60 minutes.

But it’s hard to meet those times, as the drone needs to be in ideal conditions.

Ideal conditions to preserve the battery charge are light wind, no rain, and temperate environments.

The good news is you only need to carry more batteries.

However, carrying more batteries increases the volume and weight the pilot must lug around. That, for some people, isn’t a downside, considering the pros.

Drone photogrammetry applications #

As drones have more pros than cons for photogrammetry, many industries use them to get important data.

Surveying #

With a drone, companies can map vast areas by programming drones to take pictures automatically from certain locations.

With the data extracted from the mapped area, the company can develop risk analyses to quantify the required safety precautions to construct a solar energy farm.

How far can the farm extend, which materials should they use, and is there zone suffering changes that affect the farm operation?

Those are common questions that are quick to solve with a drone’s help.

An agricultural field receives assistance from drone photogrammetry with 2D multispectral mapping.

The drone takes aerial pictures to recreate the area to study with different lighting conditions we can’t see with our eyes.

Those maps can unveil plant diseases, growth patterns, and field interactions within the environment.

Remote inspections #

The condition of pipes is essential for the safe operation of the gas and oil industry. To check those pipes, the technicians had to go and inspect every pipe in situ.

This activity is dangerous as the technician is subjected to gases and harsh environmental conditions for long periods.

With a drone, the technician performs a visual remote inspection after processing a pipe model in 3D, thanks to the images the drone took.

From the comfort of a desk, the technician can now inspect and measure any anomalies and program a visual in-situ inspection.

Environmental monitoring #

Another application of drone photogrammetry is the monitoring of critical environments.

With a drone, you can safely monitor a volcano and predict how it will behave before, during, and after erupting. You can gather data such as where the lava will flow and which areas have the most exposure.

And the best part is that you can share that information almost instantly without needing a super PC. That way, these companies can spread their conclusions for immediate preventive actions.

Minimum requirements for drone photogrammetry #

So a drone is a very useful tool to make a living by helping people and businesses.

But does my drone work for photogrammetry?

The harsh truth is that drones that work for photogrammetry need to fill some requirements that you generally find in flagship drones.

Top-notch camera and gimbal #

The minimum requirement for the camera is 20 MP with a 1-inch camera sensor for topographic mapping. This will give you non-distorted images to overlap and get accurate measurements.

However, you can accomplish photogrammetry of a small zone with a drone like the DJI Mini 3 Pro.

We wrote an article about this drone’s suitability for mapping when you understand its weaknesses. Thanks to the new SDK released, you can now use photogrammetry software with this drone.

The Mini 3 Pro won’t provide the most exact data, but it’s useful for developing a risk analysis in locations like a small-size bridge.

» MORE: DJI Mini 3 Pro for Mapping (All You Need to Know)

Self-stabilization #

The lighter a drone is, the easy the wind will move it. The heavier a drone is, the more battery output will need.

Balancing the weight is tricky, so manufacturers opt to design a drone with materials and components that are durable but light. The idea is to improve the battery charge to last a long time.

The best way to make your drone stable is with a GNSS system. These drones have reliable transmitters and receivers, guaranteeing your drone will correct its position.

That way, the drone can hold its position to take stable images.

Reliable battery #

Drones don’t shine for their flying time.

However, batteries for photogrammetry drones tend to last longer than the usual drone battery.

A typical photogrammetry drone has a flight time of 30 minutes, with the best options lasting up to 50 minutes.

The idea of having batteries that provide usable flying times is due to these drones’ long range. And the necessity of transmitting accurate data.

A reliable battery helps the drone complete the flight mission safely by covering kilometers to take the required shots.

Software compatibility #

The drone can only take photos, so you must provide it with photogrammetric software. These programs help pilots develop a flight path the drone will cover automatically.

Some drones will have full compatibility with the most reliable software, while others won’t.

The good news is you find plenty of software on the market, giving you enough options to find the one that suits your drone best.

Pilot experience #

Although it sounds cliché, an experienced pilot can take accurate pictures for photogrammetry with a non-enterprise drone.

We want you to eliminate the idea you need the holy grail drone for this work.

A DJI Air 2S works perfectly for photogrammetry, having a 20MP 1-inch CMOS camera sensor with 20 minutes of flying time in windy conditions. It’s a drone that is way below the price of an enterprise drone.

So if you want to enter photogrammetry by offering your services with your non-enterprise drone, you can check our guide to mapping and surveying at this link.