Drone photogrammetry

Drone Photogrammetry is the science of collecting physical information from 2D photos, often aerial images captured by drones. By combining enough overlapping images of the same features, photogrammetry software can be used to generate photorealistic 3D representations of topographic surfaces.

To understand how drones can be utilized in surveying, let us remind you quickly about drone photogrammetry. It involves taking multiple aerial images of a feature and using them to create digitized high-resolution 2D or 3D models from which accurate measurements can be deduced. This can be completed with specialized mapping software that looks for common features in images and uses them to stitch your photos together in a way that offers an accurate representation of a space. While typically a coordinate point, the exact common feature can vary based on what type of photogrammetry you’re using (more on that later). Depending on the scope of the project, a model made with photogrammetry may require anywhere from a couple hundred to several thousand separate images.

One of the key advantages of photogrammetric aerial photography is that it can be used to create multiple kinds of maps. Depending on the kind of photogrammetry software you have, it is possible to create a variety of outputs, like orthomosaic maps, 3D point cloud models, Digital Surface Models, and more. Other types of mapping, like LiDAR — which uses pulses of light to measure topography — will require a separate payload, however.

Photogrammetry can be broadly divided into two categories:

Metric photogrammetry: This method uses coordinate points on features to visualize an object with near exact measurements. Maps can then be built based on the location of coordinates relative to each other. These coordinates are usually physically set with what is called ground control points.

Interpretive photogrammetry: Rather than specific coordinates, interpretive photogrammetry takes a photograph and adds in topography by looking at indicators like the shapes, shadows, and patterns presented in an image, rather than coordinates.

Each style of photogrammetry can be used for land surveying, depending on the specifics of the job and attention to detail needed. Overall, however, metric photogrammetry is the more precise of the two and is recommended for surveying jobs that need centimeter-level accuracy. Both styles depend on specialized mapping software to stitch together images into a photogrammetric map.

Applications for drone photogrammetry

Construction: Surveying with photogrammetry can reveal information about the land being built on. In addition, aerial modeling with drones can assist in BIM and overall construction project management.

Real estate: Realtors are using drones to make accurate 3D models of homes for sale and offer virtual tours. This technique has taken off because of the COVID-19 pandemic.

Engineering: Engineers can use photogrammetric images to build a 3D model of both buildings and equipment

Energy: Oil and gas companies use drones to monitor the areas around pipelines for environmental changes over time. Land surveying is also commonly implemented in this sector.

Drone videography

We are a leading, experienced provider of  Drone Videography services based in Singapore, with a dedicated team of highly skilled drone pilots. Using the latest drone platforms, we provide aerial photos and videos for hotels, real estate, maritime industry, broadcast, and many other industrial and commercial purposes.

We are proud to have worked on aerial filming projects for almost all the major property firms in Singapore, as well as production houses of all sizes. Our drone photography work has been used in print, outdoor advertising, as well as for industrial purposes such as progress reporting, inspections, etc.

Industries & Applications of Drone Videography

Real Estate / Property

We proud to have produced many property marketing photos and videos for our clients in the real estate industry.We service most real estate companies in Singapore. Our clients have come to trust us for our reliability, experience, and strong local knowledge of the different neighborhoods and property types in Singapore. We manage client risks with our knowledge of local laws and regulations to ensure clients achieve great results while operating within the limits of the drone legal framework in Singapore.We have the capabilities to produce a marketing video from end-to-end, providing you with a one-stop solution, should you also require ground video shooting services.

Events & Drone Live Feed

Having been involved in supporting many events with aerial photography and drone video filming, aerial photography.sg knows exactly what needs to be done to get the shots you want. From large scale events such as the National Day Parade to intimate corporate and group functions, we have done them all. We are also able to support events with drone live feed service.

TV Commercials & Broadcast

We have provided drone support and value-added to the TVC productions for esteemed clients in both the public and private sectors, such as OCBC, NEA, MCCY, Anlene. In addition, we have worked on projects such as TV documentaries where our drone video footage was used extensively.

We work in a collaborative manner with producers and directors, often providing suggestions on feasible locations and angles to fulfill client objectives. Our deep local knowledge and experience in navigating the legal drone framework allows us to achieve TVC directors’ specific needs while managing client risks.

Travel & Tourism

Besides providing drone support to production houses for travel and tourism-related aerial videos in Singapore, we have also worked on numerous overseas projects filming hotels and resorts.

Our experience in shooting drone photos and video footage of hotels, resorts and tourism-related businesses allow us to produce superior quality images and videos that help our clients position their products and services above their competition sets.

Drone survey

A drone survey refers to the use of a drone, or unmanned aerial vehicle (UAV), to capture aerial data with downward-facing sensors, such as RGB or multispectral cameras, and LIDAR payloads. During a drone survey with an RGB camera, the ground is photographed several times from different angles, and each image is tagged with coordinates.

What are the benefits of drones in surveying?

Reduce field time and survey costs

Capturing topographic data with a drone is up to five times faster than with land-based methods and requires less manpower. With PPK geo-tagging, you also save time, as placing numerous GCPs is no longer necessary. You ultimately deliver your survey results faster and at a lower cost.

Provide accurate and exhaustive data

Total stations only measure individual points. One drone flight produces thousands of measurements, which can be represented in different formats (orthomosaic, point cloud, DTM, DSM, contour lines, etc.). Each pixel of the produced map or point of the 3D model contains 3D geo-data.

Map otherwise inaccessible areas

An aerial mapping drone can take off and fly almost anywhere. You are no longer limited by unreachable areas, unsafe steep slopes, or harsh terrain unsuitable for traditional measuring tools. You do not need to close highways or train tracks. In fact, you can capture data during operation without an organizational overhead.

What are drones used for surveying?

Land surveying/cartography

Survey drones generate high-resolution orthomosaics and detailed 3D models of areas where low-quality, outdated, or even no data, are available. They thus enable high-accuracy cadastral maps to be produced quickly and easily, even in complex or difficult-to-access environments. Surveyors can also extract features from the images, such as signs, curbs, road markers, fire hydrants, and drains.

Land management and development

Aerial images taken by drones greatly accelerate and simplify topographic surveys for land management and planning. This holds true for site scouting, allotment planning, and design, as well as final construction of roads, buildings, and utilities.

These images also provide the foundation for detailed models of site topography for pre-construction engineering studies. The generated data can also be transferred to any CAD or BIM software so that engineers can immediately start working from a 3D model.

As data collection by drones is easily repeatable at low cost, images can be taken at regular intervals and overlaid on the original blueprints to assess whether the construction work is moving according to plan specifications.

Precise measurements

High resolution orthophotos enable surveyors to perform highly accurate distance and surface measurements.

Stockpile volumetric measurements

With 3D mapping software, it is also possible to obtain volumetric measurements from the very same images. This fast and inexpensive method of volume measurement is particularly useful to calculate stocks in mines and quarries for inventory or monitoring purposes.

Slope monitoring

With automated GIS analysis, it is possible to extract slope measurements from DTMs and DSMs generated by drone imagery. Knowing the steepness of the ground’s surface, the areas can be classified and used for slope monitoring purposes, including landslide mitigation and prevention.

Drone specialist

Real Drone Specialists have an eye for good composition as well as having a high level of communication skills. Specialist work hand in hand with senior staff to create and maintain relationships, drives to existing appointments to shoot residential photography with the company designated equipment which includes a DJI Drone and Matterport 3d Cameras.

Responsibilities as a drone specialist

• As a drone specialist flying in the specific category,  you must:
• ensure that the drone displays the drone specialist registration number (e.g., with a sticker) and the same number is uploaded into the remote identification.
• develop operational procedures (written procedures are required when the drone specialist employs more than one remote pilot, otherwise it is enough that the remote pilot follows the procedures defined by the manufacturer in the user’s manual).
• ensure that there is no radio interference that may affect the command-and-control link of the drone.
• designate a remote pilot for each operation; it is important that it is clear who is the person responsible for each flight.
• ensure that the remote pilot and the personnel supporting the operation of the drone are familiar with the user’s manual and with the drone operator’s procedures, have appropriate competency, and are provided with the relevant information concerning any geographical zones published by the MS.
• ensure that the maps in the geo-awareness system of the drone are up to date unless you are flying in a geographical zone where geo-awareness is not required.
• ensure that, unless you are using a privately built drone, it has a declaration in conformity to the CE class mark and its class label (0 to 4) is affixed to the aircraft; and
• ensure that the persons involved in the operation of the drone is aware of the risks involved in operations under subcategories A2 and A3.
• carry out each operation within the limitations defined in the declaration or operational authorization.
• develop procedures to ensure the security of the operation.
• establish measures against unlawful interference and unauthorized access.
• ensure that the privacy of people is protected, and there may also be a requirement to conduct a data protection impact assessment if requested by the National Aviation Authority.
• provide the remote pilot with guidelines on how to minimize the nuisance caused by noise and emissions.
• ensure that the pilot conducting the operation and the other person in charge comply with all the conditions required for operating in the ’specific’ category.
• keep a record of the drone operation; and
• maintain the drone in a suitable condition to ensure safe operation.

Type of aerial photography

Aerial photography is a fascinating specialty that professionals employ for a variety of reasons, and there are numerous sorts of aerial photography. Aerial photography is the practice of shooting images from a high altitude, generally with the aid of an airborne object, such as rockets, airplanes, hot air balloons, and, more recently, drones.

The camera axis (angle of the photo), the image scale (proximity and width of the area in the photograph), and the type of film are all factors that experts consider when categorizing aerial photography. This photographic specialty offers a variety of applications, but first, let’s take a look at the different categories.

In each of the three primary categories, there are various different forms of aerial pictures. The subject and aim of the imagery often determine which type of aerial photography is used.Here we share a camera Axis in this article.

Camera Axis

Vertical photographs are those in which the camera’s axis is vertical. As a result, there is little to no relief evident in the photograph and the area covered is reduced. Vertical pictures, such as a map, are frequently used by experts.

Low oblique images–unlike vertical photographs, low oblique photographs are taken by tilting the camera axis more than 3 degrees such that the horizon–the point where the earth and sky meet–is not visible.

Photographs taken at a high oblique angle–the camera axis is tilted to a greater degree–approximately 60 degrees–covering a bigger region and allowing the horizon to be seen. This level of tilt, in contrast to vertical pictures, creates a lot of relief. This makes it easier to distinguish between natural and man-made features.

The commonly used photographs

Experts more often use vertical photographs like a map. The choice between vertical and oblique photos is influenced by the flying conditions. In turbulent, unstable situations, taking vertical aerial images is difficult, hence many photographers choose to take aerial photographs using a tilted camera axis.

If the camera axis is inclined more than 3 degrees, you classify the image as oblique. Vertical photos, as opposed to oblique photographs, are still considered to be those angled less than 3 degrees. Oblique images aid in the identification of geological or archaeological elements by revealing the topography in relief. For mapping, vertical pictures are preferable.

Oblique shots, on the other hand, are easier to take in a wide range of weather situations, which is why most photographers prefer them. Oblique pictures are better for topography, geographic surveys, and identifying archaeological features since they produce final images with a wider view.

What is the difference between a high oblique aerial shot and a low oblique aerial shot?

The difference is in the angle at which the camera axis is tilted. The tilt of vertical photos is 3 degrees or less. It is a high oblique aerial shot if the tilt is sufficient to capture the horizon in the aerial photograph (60 degrees from vertical or more). If it isn’t (about 30 degrees from vertical), the tilt is smaller, making it low oblique.

Lens system for aerial photographs

Aerial photography normally involves a minimum of two camera lenses attached together, which is known as a 2 lens system. You can also use more lenses. For example, you can use a 3 lens system to capture an area from horizon to horizon. Photographers used this type of system, also called a trimetrogen system, which was used in world war two to map enemy territory.

The best time of the day for Aerial Photography

It depends on what you are hoping to photograph. If you are aerial mapping, and you don’t want shadows, the best time of the day will be close to noon. But if you are trying to capture the face of a mountain against the blurred sky, the morning might be better. The golfer’s hour is also good if you are trying to capture a capture in full color.