Month: April 2023

Photogrammetry vs Lidar Remote Sensing

As remote sensing technology continues to develop and improve, we’re seeing more potential uses and opportunities to create value in new industries and fields of study, from environmental science to public safety to telecommunications.

Several different remote sensing methods are available today, and each one comes with strengths and limitations. Some will be well-suited for one application but not others. How do you determine which is best for your industry?

In this post, we’ll go over two popular remote sensing technologies, LiDAR and photogrammetry, and discuss some key differences between them.

photogrammetry vs lidar

LiDAR vs. Photogrammetry: A Two-Minute Primer

Remote sensing allows people to capture and collect important environmental or structural data faster and more accurately than ever before. Here’s a breakdown of two popular data collection practices: LiDAR and photogrammetry.

What is LiDAR?

LiDAR, or light detection and ranging, uses points of light to create a detailed map of an object’s position in space. It has been used to power everything from automated driving technology to augmented reality to advanced topographic surveying.

When mounted from an unmanned aerial vehicle (UAV) or airplane, LiDAR can be used to directly measure the height and density of land and vegetation below, including detailed data on ground cover and trees. This remote sensing method is valuable for mapping structure, density, and other local characteristics of large land parcels from overhead.

3D visual made with LiDAR

What Is Photogrammetry?

Photogrammetry uses image overlap and UAV-captured images to produce a robust 3D composite of a region. By using ultra high-resolution image collection in concert with advanced GPS and mapping software, photogrammetry can produce a fully immersive 3D visual model of the real world. More than a survey map, this process creates an interactive photographic artifact that can be deployed by environmental agencies, construction firms, utility companies, and more.

Popular Use Cases for LiDAR Remote Sensing and Photogrammetry

Mining and geology
Forestry management
Hazard assessment
Oil & Gas
First response

What else can remote sensing do? Here are some examples in the news from across various industries and disciplines:

Want to learn more about remote sensing technology? Read our Complete Guide to Remote Sensing.

How does LiDAR work?

LiDAR uses basic physics and geometry to uncover remarkable insights. To do so, it uses the power of a laser directed down toward the earth’s surface and fired in rapid succession—in most cases, at a rate of many thousand pulses per second. The amount of time it takes for the light to return to the source indicates its exact distance. LiDAR works like echolocation in bats or submarines, but it’s powered by the incredible speed of light (about 186,000 miles per second, if you’re keeping score at home).

Data generated by LiDAR sensors is collected and pinned to GPS metadata to create a detailed map of the landscape. To produce an accurate picture, data from remote sensing tech is then layered to cross-reference ground points and flag errors and inaccuracies.

A LiDAR instrument typically uses three component pieces to collect data:

  • A laser produces light that is used as the measurement medium. 
  • Reflected light from the ground is collected by the photodetector sensor and optics.
  • A GPS receiver documents the exact position of thousands of data points in real time.

Popular Remote Sensing Use Cases for LiDAR

  • Surveying
  • Augmented reality
  • Automated driving
  • Hazard assessment on lava flows, landslides, tsunamis, and floods

Types of LiDAR

LiDAR can be deployed in a number of ways depending on the application and the type of data capture required, including:

  • Terrestrial: Either static or mounted on a moving vehicle, this type of LiDAR is best suited when a detailed view of the ground is desired.
  • Airborne: When the goal is to capture data across vast areas, LiDAR cameras can be mounted on a drone or aircraft. 
  • Satellite: For an even larger bird’s-eye view, satellite-mounted LiDAR captures data about the atmosphere in addition to the terrain below.

Challenges and Opportunities in LiDAR Remote Sensing

As with any type of technology, LiDAR remote sensing has advantages and disadvantages. The primary challenges are around cost and reliability, while opportunities lie in its accuracy, speed, and functionality. 

When compared to cameras, LiDAR equipment is more costly, and the expenses related to capturing data must also be considered. With multiple moving parts, LiDAR equipment must sometimes be repaired, potentially impacting its reliability. 

Because it uses lasers, LiDAR delivers extremely accurate results and is able to capture small details in a short period of time. This high-resolution data can be used to create 3D maps that are useful for a broad range of applications.

How does photogrammetry work?

The defining feature of photogrammetry is the use of ultra high-resolution aerial photography. By capturing multiple images over a landscape, a “stereo” version is produced that provides software with differing views of a single focal point (for an example of how this works, look at a nearby object and alternate closing one eye and then the other). This shifting perspective creates scale that is used to create a composite image with accurate, measurable definition.

These photographs can collect enormous amounts of data from huge swaths of land. Like LiDAR, photogrammetry can be used to survey structures or properties with incredible accuracy. In addition, this remote surveying method produces a photographic document of on-the-ground conditions that can be used to perform surveillance, track changes in an environment, or create 3D interactive maps of a property.

Popular Remote Sensing Use Cases for Photogrammetry

Types of Photogrammetry

Just as with LiDAR remote sensing, photogrammetry can be captured on the ground (either static or mobile), in the air (from a helicopter, plane, or drone), or from space (with a satellite). The most appropriate method will depend on the application. 

For example, a construction site might benefit from static photogrammetry to identify potential hazards or monitor progress. On the other hand, that same construction project might also benefit from drone photogrammetry to verify existing conditions or compare built conditions to drawings. 

Challenges and Opportunities in Photogrammetry

Photogrammetry is a powerful tool, but in some cases, it might have limitations. For example, if there is low contrast or a uniform texture, it may be difficult to discern details in the images. Atmospheric conditions might also affect image quality, although this is often less of a concern with terrestrial and drone photogrammetry.

On the plus side, photogrammetry is comparatively less expensive than LiDAR remote sensing and comes with the same speed. Imagery provides an accurate, real-world snapshot of the terrain, structures, and other conditions with a high level of resolution.

What Sets LiDAR and Photogrammetry Apart?

Both LiDAR and photogrammetry are highly accurate for surveying buildings, infrastructure, and raw land. LiDAR can collect more detailed depth information than photogrammetry, but photogrammetry includes detailed visual information on the environment which is indispensable for many researchers.

When it comes to dollars-and-cents decision-making, LiDAR tends to be more costly and more difficult to set up and calibrate, especially when mounted on surveying airplanes and helicopters. However, the cost of both photogrammetry and LiDAR are dropping thanks to the widespread adoption of UAV technology across industries.

Read about how UAV photogrammetry can go beyond surveying and mapping to cut costs, improve data quality, and transform entire industries.

Choosing the Right Data-Processing Solution

Selecting the right approach to mapping is the first step, but finding the right partner for the job is equally important. Mapware has the remote sensing technology and the expertise to create value for you and your customers.

Mapware’s photogrammetry software is the best tool for the job, whether you want to map a single building, a dozen oil derricks, a protected wetland, or an entire city. This software suite generates bigger, better 3D maps that are fully cloud accessible for use in the field.

learn how the public sector drives innovation with geospatial intelligence and data driven mapping ebook

This article, originally posted on June 1, 2020, was updated April 27, 2023.

How Drone Pipeline Inspection is Revolutionizing Surveying

Pipelines require a lot of data collection to operate smoothly and safely. Traditionally, this data has not been cheap or easy to obtain. Pipeline industry professionals are increasingly turning to unmanned aerial vehicles (UAVs, or drones) to meet these challenges.

According to some estimates, the UAV industry is expected to grow to $56 billion by 2030. The oil and gas industry can benefit significantly from this growth and its implication for drone surveying.

What Are the Benefits of Drone Pipeline Inspection?

UAV technology can safely and inexpensively perform a variety of pipeline operation tasks, collect a wide range of data, and contribute to predictive analysis to deliver benefits for multiple stakeholders. 

Maximize Plant Uptime and Reduce Costs

Plant downtime cuts into profits, and drones can help identify avoidable reasons for a shutdown. UAVs also contribute to a better bottom line by reducing labor costs for tasks that can be automated and improved.

Improve Worker Safety and Reduce Liability

Surveying planned routes, monitoring construction activities, and identifying potential hazards can prevent accidents before they happen and improve worker safety. 

Provide a Force Multiplier

Drones can quickly and autonomously gather an incredible wealth of information to help meet regulatory requirements and mitigate potential threats to pipeline integrity. You can’t do this with boots on the ground alone.

Detect Leaks Early

Inspecting existing lines for leaks and corrosion is a necessary part of operating a pipeline. Supplementing with drone pipeline inspection allows you to automatically detect changes—including those invisible to the naked eye—to do this more efficiently and effectively. 

Aerial Challenges in the Pipeline Industry

The capabilities of modern drones are impressive, but utilizing UAVs effectively is not so simple. A pipeline operator must consider many factors if they want to be successful: where the pipeline is located, how long it is, the kind of data to be collected, and so on.

Some utilities have invested heavily in developing in-house drone programs, but many others are relying on third-party service providers. As UAVs become more popular, the opportunities for these professionals (and the pipeline operators they serve) are growing every day.

Weekly Pipeline Inspections

Performing weekly pipeline inspections is routine for Bill Washek, a pipeline operations supervisor from Oklahoma City. “We fly the entire right-of-way twice a month for aerial inspections, but we have boots on the ground every week. A big part of our budget goes to that,” says Washek. 

This is nothing out of the ordinary. Inspections and continual monitoring are major cost drivers at nearly every stage in the life of a pipeline. “The biggest cost is the number of people it takes,” says Washek. “If we could automate inspections, that would save me a bundle.”

Pipeline Route Vetting

Before a pipeline can be built, the entire route must be vetted. Topography, the existence of other utilities, and property boundaries—all of these factors impact where pipelines may be constructed.

Currently, aerial inspection is the best option to assess these factors. But with the rapid pace of new home and business construction, the lay of the land is always changing. Even after a route has been approved, adjacent construction projects often threaten to encroach on pipeline activity.

Post-Construction Line Inspections

Although building a pipeline is a complex undertaking, the real challenge begins after a pipeline has been constructed. Regulatory standards require frequent line inspections, a task that takes time and resources. 

Many operators pay pilots to perform aerial inspections using airplanes or helicopters equipped with thermal-sensing cameras. These cameras measure temperature changes along the pipeline to detect potential leaks. The pilots also look for construction activity that may be occurring near the pipeline’s right-of-way.

Pipeline Damage Detection

The biggest threat to pipeline safety in the United States is third-party damage (TPD). TPD occurs when someone not associated with the operator damages a pipeline. These types of incidents pose a unique threat because, in many cases, the damaging party does not report it to anyone. Outside construction activity is one of the biggest causes of TPD according to the Excavation Safety Magazine, and this activity is typically easiest to spot from the air.

Another constant threat to pipelines is corrosion. Coatings are applied to steel pipelines to prevent corrosion, but that’s not always enough. Corrosion under insulation (CUI) can be impossible to see with the human eye. Special cameras attached to aircraft can detect CUI before it becomes a problem.

How Drone Surveying Is Used in Pipeline Inspections

Drone pipeline inspection provides many advantages over traditional methods. By reducing the need for human interaction, operators can improve safety, technical capability, and speed of deployment while reducing costs.

Gain Access to Remote or Hazardous Areas

Many pipelines are built in remote areas to mitigate the risk of human interference. UAV technology can make hard-to-reach infrastructure more accessible. And although geography poses unique threats everywhere in the world—from flooding and fires to landslides and slips—a UAV is largely impervious to these hazards. Drones can also access much tighter spaces and fly closer to the ground than an airplane or a helicopter.

Save on Cost and Labor 

The EPA estimates that the natural gas industry spends $50 million annually on pipeline inspections. These inspections typically require special training, and one person can only accomplish so much in a day, so it takes many people to stay compliant.

What if an individual could use a drone to do many of these inspection tasks at one time? Or better yet, what if a drone could be programmed to do them autonomously and simply report the data back to the control center?

Reduce Time for Deployment

Another key advantage of drone pipeline inspection is the reduced time it takes for deployment. Trained pilots are in high demand and have limited availability. It can take days or weeks to find someone with the qualifications and the availability to do an unplanned aerial patrol. Even then, the cost still has to be taken into consideration.

In contrast, a trained UAV operator can launch a drone and begin collecting data in just a matter of minutes. Having an inspection-ready drone can be a real game changer, especially in a time crunch.

What UAV Technology Options are Available to Pipeline Operators?

Pipeline operators have several options for utilizing drones, including the following:

Third-Party Drone Services

For many operators, contracting out drone pipeline inspection and other UAV work makes the most sense. A growing number of companies specialize in custom drone services for the oil and gas industry.

Why not just get a drone and operate it yourself? Because drones are aerial vehicles, they require special licenses to operate. Drone service providers already possess the requisite licenses for flying drones, along with the appropriate liability insurance. Plus, a trained drone specialist can determine exactly which types of drones, sensors, and software are necessary to gather appropriate data.

In-House Drone Programs

Another option is to develop an in-house drone program. If an operator wants to use drones daily or weekly—or requires a level of control that a third party cannot offer—then it may make sense to take this route.

However, this is a time- and resource-intensive enterprise. An operator who has no prior experience with drones will probably need to hire a UAV consultant to get started.

In addition, a company electing to pursue an in-house UAV program will be responsible for maintaining insurance and licenses, and it must adhere to strict Federal Aviation Administration (FAA) regulations. 

Nevertheless, the rewards can be great. Cost savings and the ability to deploy drones without relying on a third party provide greater flexibility. 

Hybrid Programs

A third option is to develop an in-house drone program and rent the actual drone hardware. This hybrid solution has its own merits. By renting drones, an operator may be able to avoid obtaining a license and insurance. In addition, new technology can be tested without committing to a large investment. Many of the companies providing drone services also offer drone rentals.

pilot deploying drone while holding tablet with mapping app

Find the Right Drone Surveying Expert for Pipeline Inspections

In order to utilize UAV technology for pipeline inspection and surveying purposes, an operator has many decisions to make. Whether they contract with a third party or develop an in-house program, a fundamental understanding of drone technology is essential.

Having the ability to monitor leaks, corrosion, and right-of-way encroachment with one inspection method while improving safety and saving money sounds like a dream come true. However, anyone who is interested in developing a drone inspection program needs to understand the complexities involved in order to be successful. 

Contacting an experienced UAV company is a good first step. Start a Mapware Free Trial to get started.

learn how the public sector drives innovation with geospatial intelligence and data driven mapping ebook

This article, originally posted on July 1, 2019, was updated April 17, 2023.