Wingtra Photogrammetry Vs. LIDAR

wingtra.com WINGTRA PHOTOGRAMMETRY VS. LIDAR GUIDE

Photogrammetry Manned Airborne Lightweight UAV LIDAR LIDAR

How does it work?

Many high-resolution A light detection and A light detection and aerial photos are taken to ranging (LIDAR) sensor ranging (LIDAR) sends out completely capture an area. sends out pulses of laser pulses of laser light and These images overlap so light and measures the measures the exact time any point on the ground is exact time it takes for them it takes for these pulses to visible in multiple photos to return as they bounce return as they bounce from and from different angles. from the ground. the ground.

Photogrammetry software Manned airborne LIDAR has Recent developments in draws on the many vantage been around for decades. LIDAR technology have points of the image data to Sensors are typically heavy reduced the weight, size create detailed 3D maps. (> 50 kg), so they require a and power consumption of With post-processing lot of power to keep them these sensors. This led to in place, precise GNSS aloft. With manned airborne a range of LIDAR solutions positions are recorded for LIDAR, you can expect to popping up on small every pixel of every image map from more than unmanned aerial vehicles availing down to cm-level 1000 m above ground level (UAV), which are available absolute accuracy in the (AGL) and cover very large on the market today. final map. areas with a rather sparse point density.

Payload WingtraOne RX1RII Leica ALS80 Yellowscan Mapper examples WingtraOne QX1 RIEGL VQ-780 II Zenmuse-L1 Trinity Qube 240

Resolution / GSD expectations Up to 20’000 px/m2 Up to 50 pts/m2 Up to 200 pts/m2 (2000 px/ft2) (5 pts/ft2) (20 pts/ft2)

Accuracy expectations ~ 2 cm (0.8 in) absolute ~ 20 cm absolute horizontal ~ 10 cm absolute horizontal horizontal accuracy accuracy accuracy ~ 3 cm (1.2 in) absolute ~ 10 cm absolute vertical ~ 5 cm absolute vertical vertical accuracy accuracy accuracy

Typical 0-10 km2 per flight 10-1’000 km2 per flight 0-10 km2 per flight coverage

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Photo- realisticity Photorealistic maps Sparse point cloud gives Sparse point cloud gives (Orthomosaic, point cloud, a general sense of shapes a general sense of shapes textured mesh) are directly and contours but lacks and contours but lacks available. contextual detail. Detail contextual detail. Detail still lacks even if the point still lacks even if the point cloud is colorized with RGB cloud is colorized with RGB data, which becomes more data, which becomes more complicated. involved.

Leaf penetration No leaf penetration. Ground No leaves penetration. No leaves penetration. below vegetation can Ground below vegetation Ground below vegetation only be reconstructed if can be reconstructed as can be reconstructed as captured from multiple long as single light beams long as single light beams viewpoints, i.e. only through can pass between the leafs, can pass between the leafs, at rather open canopy. i.e. on half-closed canopy. i.e. on half-closed canopy.

Workflow & support Companies like Pix4D, Point clouds from manned Companies like Phoenix Agisoft, Bentley CC, aerial LIDAR require trained Lidar Systems, GeoCue and Propeller or DroneDeploy professionals to oversee Yellowscan are pioneering have optimized post processing. While it is towards a streamlined data photogrammetry workflows well-established, it requires processing workflow. Still over years of experience expertise. today, the process typically with much data. Cloud/ involves multiple manual server solutions allow steps, different tools and for large-scale data expert knowhow to develop processing with minimal an accurate point cloud. hardware investment. Dedicated support teams are available to help you.

Processing time ? Processing with full Typically large-scale Point clouds are typically resolution takes several datasets are developed available after a few hours (or days) depending over months with multiple post processing steps on the project size. correction steps. The like strip adjustment and If only a sparse set of processing time can not noise filtering. For smaller accurate tie points (like be compared to the other projects, you can get from a LIDAR source) is methods. results in less than 1 hour required, fast processing after the flight. options on downsampled data is offered by all photogrammetry tools.

Payload price

USD 4’000 - 13’000 From USD 100’000 USD 65’000 - 100’000

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Application Suggested Why? Use case/research/ Technology resources

Topographic survey Photogrammetry With photogrammetry, California wildfire damage without or with light/ you produce denser, richer, assessment amidst sparse vegetation E.g., WingtraOne RX1 + more accurate point redwood forest stands Pix4DMapper clouds than with LIDAR. (use case) This leads to a more accurate digital terrain High-accuracy port survey model (DTM) and hence for Ports of Indiana more accurate contours. (use case) The contextual data and the high resolution also Cadastral vineyard survey allows you to create better (use case) vector data than from a sparse LIDAR point cloud.

Plus, photogrammetry is typically cheaper than airborne LIDAR.

Topographic survey Photogrammetry + point If part of your map is How to combine with vegetation ground survey covered with vegetation photogrammetry and that features a closed LIDAR E.g., WingtraOne RX1 canopy, we recommend (use cases) + Trimble SX10 + complementing aerial Pix4DMapper photogrammetry with Autodesk course on a ground survey to combining point clouds capture the forest floor. and LIDAR This way, you benefit (course) from the advantages of photogrammetry with minimal additional effort.

These solutions combined are also typically cheaper than airborne LIDAR.

Mapping through Manned Airborne LIDAR For large forests with Louisiana Statewide LIDAR forests on a large dense but penetrable Project (Leica ALS40) scale / infrastructure E.g., Leica ALS80 canopy, aerial LIDAR is (use case) construction your most efficient method feasibility studies to capture the forest floor. Remote sensing guidelines (pre-cleaning In many areas of the world, from World Wildlife state agencies provide Federation such terrain models on a (use case/guidelines) large scale. And for these applications, manned Using LIDAR to map forest aerial LIDAR is the right biomass technology. (research)

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Mining / bare Photogrammetry With photogrammetry, Westemoreland Mining’s earth: volume you produce denser, richer use of photogrammetry to calculations, site E.g., WingtraOne RX1 + and more accurate point enhance workflows management, cut Pix4DMapper clouds than with LIDAR. (use case) and fill assessment, This leads to a more stockpile reporting, accurate digital terrain Accurate volumetrics pits and ponds model (DTM) and hence and site surveys with more accurate volume photogrammetry at calculations and contours. Jellinbah mine sites The contextual data and (use case) the high resolution allows you to create better Massive, cost-effective reports and streamlines geothermal energy your site management. site surveys with photogrammetry Plus, photogrammetry is (use case) typically cheaper than airborne LIDAR.

Power lines, for Photogrammetry For several years, Photogrammetry vs. LIDAR vegetation control companies like Alteia, in power line inspections E.g., WingtraOne RX1 + Pix4D and DJI have proven (proof-of-concept guide) Alteia that powerlines can be reconstructed robustly Improved power line from photogrammetry as extraction methodology long as a high-end camera (research) with high resolution is used. The benefit that User experience you get from the rich with both LIDAR and photorealistic information photogrammetry for this and the lower price make application this the preferred solution. (use case)

Largest European power grid operator’s use of LIDAR (use case)

Power lines, for pole / Live-video from From a live inspection with How power line inspection tower inspection multicopter (RGB and/or a multicopter with RGB is most effective with Thermal) and thermal video feed, drones you get all information (use cases) E.g., DJI with within a very short amount FLIR Duo Pro R of time. Zoom cameras allow you to inspect details that are not offered by photogrammetry or LIDAR today.

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Rail track inspection Terrestrial/mobile Rail track inspection from Comprehensive guide to measurements (ultrasonic, both photogrammetry and rail inspection with drones visual, LIDAR, etc.) aerial LIDAR is an active (case studies) research field with pros E.g., RTI 8800SX and cons on both sides. Rail track detection and The gold standard today, projection based on 3D providing information modeling beyond what is visible (research) (rail track damages like cracks), is offered by Ultrasonic sensor mobile surveys conducted application from a train equipped (use case) with ultrasonic, visual and LIDAR sensors.

Vertical structures Photogrammetry With photogrammetry and Reality modeling in / city mapping / 3D (emphasizing nadir and/or oblique imagery gathered Medina, Saudi Arabia mapping oblique capture) by a tilted aerial camera (use case) or a wide-angle lens, you E.g., WingtraOne QX1 get better resolution and Cancún city mapping 15mm + Pix4DMapper higher accuracy at a lower project price than from a LIDAR (use case) survey. Photorealistic information is typically High-accuracy port survey also required for 3D for Ports of Indiana mapping applications. (use case)

Read the full comparison here.

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