Two Different Ways of Capturing Reality
Aerial Photogrammetry uses overlapping high-resolution photographs to reconstruct a site in three dimensions. Specialized software identifies matching features between the images and transforms them into measurable digital data. Aerial LiDAR Mapping uses laser pulses to measure surfaces and create a three-dimensional point cloud. Both technologies produce detailed information, but the way they collect data makes each better suited for different conditions.
“Having advanced technology gives us options. Knowing when and how to use each technology is what turns those options into useful project data.” — Keith Christensen, Director of Reality Capture Operations
Where Photogrammetry Excels
Photogrammetry performs exceptionally well when the project area is open and the features being captured are clearly visible from the air. Commercial developments, subdivisions, construction sites, earthwork projects, and transportation corridors are often excellent candidates. One of photogrammetry's biggest advantages is the visual information it provides. In addition to measurable three-dimensional data, an orthomosaic gives project teams a detailed aerial image of the site. This makes photogrammetry especially useful for existing-conditions documentation, design coordination, construction progress, and projects where measurements and visual context are both important.
Where LiDAR Excels
The biggest difference between photogrammetry and LiDAR often becomes apparent when vegetation enters the picture. Photogrammetry can only reconstruct surfaces the camera can see. If trees or dense vegetation block the ground, the imagery cannot reliably capture the terrain underneath. LiDAR has an advantage in these environments because laser pulses can travel through openings in vegetation and reach the ground. During processing, our team can classify those ground returns separately from vegetation and other features. This makes Aerial LiDAR Mapping especially valuable for wooded properties, drainage corridors, undeveloped land, transportation routes, and projects requiring terrain information beneath vegetation. LiDAR is not literally seeing through trees. It is collecting measurements through openings in the canopy that aerial photography may not be able to capture.
It Is Not Always About Vegetation
Vegetation is one of the easiest ways to explain the difference, but it is not the only factor. Site size, terrain, surface conditions, accuracy requirements, schedule, safety, accessibility, and final deliverables can all influence which collection method is most appropriate. That is why our team evaluates each project before choosing a sensor. Technology should follow the needs of the project, not the other way around.
Sometimes the Best Answer Is Both
Photogrammetry versus LiDAR does not always have to be an either-or decision. On some projects, combining the technologies provides a more complete picture. LiDAR can provide detailed terrain information, particularly in vegetated areas, while photogrammetry provides high-resolution aerial imagery and visual context. Having both capabilities allows Eagle Surveying to build the collection strategy around the project rather than forcing every project into a single technology.
Quick Comparison: Photogrammetry vs. LiDAR
| Project Condition | Photogrammetry | LiDAR |
|---|---|---|
| Open site | Excellent | Excellent |
| Dense vegetation | Limited | Excellent |
| High-resolution imagery | Excellent | Limited |
| Bare-earth terrain | Good when visible | Excellent |
| Construction progress | Excellent | Good |
| Visual documentation | Excellent | Limited |
| Combination needed | Sometimes | Sometimes |
Accuracy Still Depends on the Workflow
Owning an advanced sensor does not automatically produce accurate survey data. Whether we are using photogrammetry or LiDAR, accuracy depends on planning, survey control, field collection, coordinate management, processing, and QA/QC. The sensor is only one part of the process. The final product depends on the complete workflow from planning through delivery.
How Eagle Surveying Chooses the Right Technology
When we evaluate a project, one of the first questions we ask is:
What does the client need from the data?
If the project requires detailed aerial imagery across an open site, photogrammetry may be the most efficient solution. If the site is heavily wooded and the client needs a reliable representation of the ground surface, LiDAR may be the better choice. If both detailed imagery and terrain beneath vegetation are important, combining the technologies may provide the most complete dataset. There is no universal answer. We start with the client's objectives and determine the best way to collect the information they need.
A Recent Eagle Surveying Project
A recent project in Westlake, Texas, is a good example of how photogrammetry and LiDAR can work together on the same site. The client needed detailed survey information along a drainage easement associated with the construction of a new home. Our Reality Capture team evaluated the property and determined that a combination of Aerial LiDAR Mapping and Aerial Photogrammetry would provide the most complete view of the existing conditions. LiDAR was used to capture detailed three-dimensional terrain information, while photogrammetry provided high-resolution aerial imagery of the property. Our team then created a georeferenced orthophoto that could be overlaid with the project surface, giving the client a clear visual representation of the property while maintaining the spatial accuracy needed for the project. By combining LiDAR and photogrammetry, we were able to provide both accurate terrain data and detailed visual context within a single coordinated dataset.
This Westlake project demonstrates why having access to multiple Reality Capture technologies matters. Instead of choosing photogrammetry or LiDAR simply because one technology was available, we used both where they added value to provide the client with a more complete understanding of the property.
Questions We Hear from Clients
Is LiDAR more accurate than Photogrammetry?
Not necessarily. Both technologies can produce highly accurate data when properly planned, controlled, processed, and quality-checked. The better question is which technology is more appropriate for the site conditions and the information the project requires.
Can LiDAR see through trees?
Not exactly. LiDAR cannot see directly through solid objects, but laser pulses can travel through gaps between leaves and branches and reach the ground. Those returns can then be identified during processing to help create a representation of the bare-earth terrain.
Is LiDAR always better because it is more advanced?
No. More advanced technology does not automatically mean a better result. On an open site where imagery and visible surface information are the primary needs, photogrammetry may be the more appropriate solution. On a heavily vegetated site where bare-earth terrain is important, LiDAR may have the advantage.
Can Eagle Surveying use both Photogrammetry and LiDAR on the same project?
Yes. Some projects benefit from combining Aerial Photogrammetry and Aerial LiDAR Mapping. Our Reality Capture team evaluates the site conditions, project goals, accuracy requirements, and final deliverables to determine whether one technology or a combination makes the most sense.
The Right Tool for the Right Project
Photogrammetry and LiDAR are sometimes treated as competing technologies, but we view them as different tools designed to solve different problems. Photogrammetry provides exceptional visual detail and efficient mapping of visible surfaces. LiDAR provides powerful three-dimensional measurements and has an advantage when terrain beneath vegetation needs to be captured. At Eagle Surveying, selecting the right technology begins with understanding what the client needs to accomplish and developing a collection strategy around those objectives.
About Reality Capture Insights
Reality Capture Insights is Eagle Surveying's monthly technical blog series exploring the technologies, workflows, and best practices behind Aerial Photogrammetry, Aerial LiDAR Mapping, Terrestrial Laser Scanning, point clouds, and other Reality Capture solutions supporting surveying, engineering, construction, and land development.
About Eagle Surveying's Reality Capture Team
The Reality Capture Department combines expertise in Aerial Photogrammetry, Aerial LiDAR Mapping, Terrestrial Laser Scanning, and advanced geospatial data processing.
- Keith Christensen — Director of Reality Capture Operations, overseeing operations, project planning, processing, quality assurance, workflow development, and strategic growth.
- Connor Fraser — Aerial Operations Manager, coordinating projects from field collection through processing and quality control.
- Cameron Lowe — FAA-certified Reality Capture Pilot, specializing in Aerial Photogrammetry and Aerial LiDAR collection.
- Darian Rick — FAA-certified Reality Capture Pilot, focused on producing complete, high-quality field datasets.
Together, our team combines technical expertise, advanced technology, and practical field experience to help clients make informed project decisions.
Continue the Conversation
Every project presents different conditions, and choosing between photogrammetry and LiDAR is not always obvious. If you are planning a project and are unsure which Reality Capture technology is the right fit, Eagle Surveying can evaluate the site, project requirements, and desired deliverables to help determine the most effective approach.
Coming Next in Reality Capture Insights
Part 3: From Point Cloud to Deliverable — What Happens After Reality Capture Data Is Collected?
Collecting the data is only the beginning. In the next installment of Reality Capture Insights, we'll go behind the scenes of the processing and QA/QC workflow and explain how captured data is transformed into useful information for surveying, engineering, design, and construction.