This website was originally created as a capstone project during my time at college. Now, it serves as an online portfolio that showcases several UAS projects I have been involved in. As the sole author, editor, and publisher of this website, please forgive any spelling and grammar errors you may encounter, as blogging is not my primary occupation.
The timeline below highlights my activity on this website:
2018: Several posts were published while I was still studying at Purdue University.
2019: I continued to publish several posts during my time at Purdue University.
2020: More posts were added to the website, and I graduated from Purdue University.
2021-2023: I have been posting regularly since starting my career.
2024: I have been posting semi regularly since volunteering and managing my career.
Disclaimer Please note that some of the content on this website may appear ambiguous or vague. This is because my team works in a highly specialized industry and we deal with proprietary information that we do not want to be copied. However, if you come across something that interests you, please don't hesitate to reach out, and we will be happy to share what we can.
Industry Background As of this post, I have spent nine years immersed in the Unmanned Aerial Systems (UAS) industry. My experience spans several hundred UAS operations, earning a degree in unmanned aerial systems, consulting for private engineering firms, and serving a diverse array of clients. This journey has not only provided me with substantial technical expertise but also the privilege of forming significant industry relationships.
Looking at my Background (Literally)
The Roles of UAVs in Line Stringing One of the most intriguing—and perhaps "shocking"—applications of UAS that I have encountered is its use in Transmission Line Stringing. The introduction of UAVs to this field marks a significant leap from traditional methods, blending modern technology with complex logistical operations to enhance efficiency and safety. (see Figure 1 for example of Line Stringing: Photo credit:dronevolt.com)
Figure 1: Example of UAV Line Stringing
Line Stringing Case StudiesReferencing the first video, I have immense respect for Skyscopes and the pilots operating these UAVs. Initially, the concept of using drones for transmission line stringing seemed far-fetched. However, as more documented case studies and recent videos from various entities have become available, the practicality and effectiveness of UAVs in this role have become undeniable. While some footage may be edited for marketing purposes, it remains a genuine representation of what UAV technology can accomplish.
Referencing the next video, PG&E and Infravision have successfully completed several missions across Europe and North America, working with utilities to implement UAV technology in their operations. Despite challenges such as wind accessibility and safety concerns, their workflow has proven both efficient and effective, showcasing the global potential of UAVs in utility work.
ConclusionFor those familiar with traditional methods of stringing transmission lines, especially in mountainous areas, the risks and time commitments associated are substantial. Some might consider helicopters as a viable alternative, but they introduce additional elements of danger and complexity. Nevertheless, UAS technology will continue to be adopted in line stringing applications for projects that fall within the safety and efficiency parameters of the mission type.
There are numerous examples of safe and unsafe UAS operators. In this post, we're going to explore an incident that happened on live TV, all the way back in 2015.
Background
Imagine you're tearing down a ski slope, and suddenly, a bladed machine nearly kills you. For Marcel Hirscher, Austria's skiing maestro, this nearly became a chilling reality—not from an avalanche, but from a plummeting drone! During a 2015 World Cup race in Madonna di Campiglio, Italy, Hirscher had an uninvited guest drop in, quite literally, just inches behind him. This wasn’t any small consumer-level toy but a 22-pound machine that appeared to have experienced a full power failure. The culprit? An irresponsible operator who failed to maintain a healthy distance from the racers.
Conclusion
This incident, while almost cartoonish, underscores a serious point: when mixing cutting-edge technology with sports, we must tread carefully to keep the spotlight on enhancing the thrill of sports without endangering it. Through Hirscher’s close shave, and through sheer luck, UAS pilots need to ensure that they take additional measures to prevent accidents like this from happening again. If you haven't already seen, check out the video below.
Overview: Hi, everyone, this is Alan Pecor. I am the sole author of this blog. Please disregard any spelling and grammar errors because blogging is not my main occupation. Apologies aside, this post is perhaps one of the most important articles I have created because it brings attention to an issue that I will never forget. This issue was brought to my attention through volunteering in Laos last year (see Figure 1 below). Let me share with you a journey that has forever changed my perspective.
Figure 1: Me Looking at Nong Khiaw Laos
Volunteer Background:In 2023, I took some time off work and ventured to Laos, a landlocked country bordered by Vietnam, Cambodia, Thailand, Myanmar, and China. My mission was twofold: to teach English and engage in environmental projects, including permaculture, which seeks to foster sustainable and self-sufficient communities. In addition to having the privilege of being immersed in Laos's culture, I was able to learn about a part of history that isn't commonly known. Amidst the breathtaking landscapes (shown in Figure 2 below) and the warmth of the local community, I became educated about the silent menace lurking beneath the soil—the legacy of unexploded ordnances (UXOs).
Laos Since the Vietnam War:Laos remains scarred by its title as the most heavily bombed country per capita in history, a consequence of over two million tons of ordnance dropped during the Vietnam War. Decades later, approximately 30% of these explosives still menace the land, claiming lives and limbs with chilling regularity. The United States, responsible for this enduring hazard, has contributed over $230 million towards clearance efforts—a figure dwarfed by the $13.3 billion (inflation-adjusted) spent on the bombing campaign. This stark disparity underscores a glaring need for increased investment in UXO clearance, a task complicated by Laos's rugged terrain and the inherent dangers of detecting buried explosives.
Figure 2: Looking at UXO Shells at UXO Visitors Centre Luang Prabang Laos
The magnitude of the problem is overwhelming, with an estimated 80 million undetonated cluster bombs continuing to pose a fatal threat to civilians. The challenge of locating these UXOs is daunting, hindered by technological and logistical constraints, yet the human cost of inaction is far greater. Referring to Figure (X), here are a few examples of UXOs that I observed at the UXO Lao History Museum, illustrating the grave reality on the ground. For further insight into the impact of UXOs, I recommend watching the video below:
UAS and UXO Removal: Innovatively, some UAVs are emerging as a critical tool in the daunting task of UXO detection. Equipped with advanced sensors and AI-driven software, UAVs can safely and efficiently survey vast areas, identifying potential UXO sites without risking human lives. Organizations like the Demining Research Community are at the forefront, pioneering the use of remote sensing, machine learning, and robotics to enhance the accuracy and safety of demining operations. This approach not only promises to accelerate the clearance process but also represents a significant leap towards safeguarding future generations from the horrors of past conflicts. For a deeper understanding of how UAV technology aids in UXO removal, watch the below video:
Conclusion: Reflecting on my time in Laos, I'm struck by the juxtaposition of its serene beauty against the hidden dangers that lie beneath. It's not my intention to portray Laos as dangerous, but it is absolutely unacceptable to ignore that innocent people are still at risk. The resilience of its people, their unwavering spirit in the face of adversity, and the innovative strides being made towards a safer future are a testament to the enduring hope that defines Laos. As we witness the potential of drone technology to mitigate the UXO threat, we're reminded of the power of human ingenuity in overcoming the remnants of war. I plan to volunteer in Laos again in the future, driven by a conviction that our collective efforts can bring about real change. This belief reinforces the notion that, no matter who you are or what your opinion is, we all have the capacity to contribute to a better world—and that includes me.
Figure 1: Review Panel Discussion at Big Brothers Big Sisters. Photo credit: Lauren Cook
On Feb 17th, I had the privilege of attending the Big Brothers Big Sisters career fair in Indianapolis, an event dedicated to inspiring and empowering young minds through mentorship and community engagement. I participated in a review panel alongside several industry professionals, where we shared insights and guidance to budding young talents. Additionally, I showcased our UAS simulators, providing students with hands-on interactive activities that allowed them to engage directly with cutting-edge technology and explore its real-world applications. Should your Big Brothers Big Sisters organization be interested in exploring UAS technology further, feel free to reach out to me for expertise and demonstrations.
When utilizing Unmanned Aerial Systems (UAS) for bridge inspections, aircraft are primarily deployed for contactless data collection. Yet, a glaring gap persists: very few UAS can test the deficiencies they identify. This oversight often results in inspectors to yet again be exposed to dangerous environments.
Enter the Voliro T UAS Thanks to its unique design, the Voliro T enables inspectors to conduct close-proximity tests eliminating the need for additional hands on inspection. Unlike most industrial UAS, this system is capable of carrying various payloads, including probes, thickness gauges, ultrasonic transducers, and impact eco systems. The tilt rotors and distinctive omnidirectional design, illustrated in Figure 1 allow this aircraft to balance itself when testing difficult to access structures.
Figure 1: Voliro T Aircraft Note: Tilt Rotors
Pushing the Boundaries Based on information fromVoliro's website, the UAS is suited for contact-based inspections of storage tanks, wind turbines, smokestacks, and various steel structures. While there's limited information currently available regarding the exact data and Return On Investment (ROI) this drone provides, Voliro T clearly boasts a novel design and holds potential to carve a niche in the UAS industry. For a deeper dive, below is a linked video showcasing the Voliro T's relevance and its impressive tilt rotor capability.
While the video contains light-hearted and promotional elements, it offers a comprehensive overview of the crucial drone laws we must follow. Personally, I find videos more engaging than reading through the FAA's written guidelines. I'd highly recommend taking the time to watch it if you're uncertain about the intricacies of FAA Part 107.
FLIR Thermal Studio Pro, developed and managed by Teledyne FLIR LLC, is a software solution that facilitates the processing and analysis of thermal data gathered through FLIR products. While some of FLIR's products are designed to integrate with handheld cameras, I have discovered that Thermal Studio Pro provides immense value in analyzing and processing our UAS imagery. Through this post, I aim to demonstrate a few techniques I have used with Thermal Studio Pro to analyze the conditions of bridge decks, utilizing the powerful tools that the software offers
Teledyne FLIR Advantages
As a frequent user of the Zenmuse XT2, I utilize it for various infrastructure inspections. FLIR provides numerous tools that are available for free download which can be found here. If you're unsure about the potential benefits, you can easily access their software here. However, please note that although the tools are free, the generated information is watermarked and cannot be practically utilized. Additionally, the free trial software has no limitations.
Teledyne FLIR Difficulties
Unfortunately, not all the tools available on FLIR's trial software are functional. When I reached out to tech support regarding the panorama tool, they informed me that it is only accessible with the purchase of Thermal Studio Pro. I am extremely disappointed with their customer service, as the lack of access to the panorama tool may render my year subscription fee useless. FLIR has made no attempt to provide me with a temporary license to test the compatibility of the panorama tool with my data. Please refer to Figure 1 to observe the lack of response
Figure 1: Teledyne FLIR's Customer Service
Features for UAS Inspections
As a novice user of FLIR Thermal Studio Pro, I find the following features to be useful for thermal deck inspections:
• Temperature Profile
• Color Pallet Tools
• Box Annotation
• Temperature Spot meter
Bridge Deck Case Study
To inspect bridge decks, we use a UAS equipped with the XT2 camera to capture sections of the decks from above. When imported to Thermal Studio Pro, the unedited file appears in black and white (Figure 2). To identify areas of concern, we use the temperature profile tool to adjust the temperature variance and better define the boundaries of bright spots (Figure 3).
Figure 2: Unedited Thermal R_JPEG File Looking at Bridge Deck
Figure 3: R-JPEG File with Profile Adjustment Looking at Bridge Deck
Next, we use the color palette tool to assign more colors to temperature and identify hotspots of concern (Figure 4). To exclude irrelevant data, we use the box annotation tool to draw a box around the area of interest (Figure 5).While we are less concerned with temperature, we can use the spot meter tool to verify the data and ensure consistency. If any patch is warmer than 95 degrees F, it is more likely to be deficient.
Figure 4: R-JPEG File with Color Pallet Looking at Bridge Deck
Figure 5: R-JPEG File with Spot Temperature Tool Looking at Hotspots on Bridge Deck
Figure 6: Example Diagram of Visual and Thermal Imagery of Bridge Deck
Tools I am Troubleshooting
We can also create a comparison diagram using FLIR Thermal Studio Pro to combine visual and thermal imagery (Figure 6).However, I find it challenging to create reports using FLIR's template, and the panorama tool doesn't seem to work with the XT2 camera despite numerous attempts with 85+ overlap. As FLIR doesn't allow a trial of the panorama tool, I'm not sure if it's compatible with the camera. Despite this, I'm still trying to use the tool.
Conclusion
I am generally satisfied with Thermal Studio Pro's performance and functionality. The software has proven to be a valuable tool for conducting UAS and infrastructure inspections, allowing me to quickly analyze and interpret thermal data in a comprehensive manner. However, their panorama tool and customer service could be better.
Introduction The drone industry has experienced significant growth in recent years, with the Federal Aviation Administration (FAA) predicting over 835,000 commercial drones in the United States by 2024. DJI Unmanned Aerial Systems (UAS) have become widely popular in public safety applications, but recent security concerns and vulnerabilities have raised alarms in the industry. This blog post will discuss these security concerns, a recent Chinese drone ban in Florida, and DroneSense's new communication device designed to address these issues and improve drone security.
DJI Security Concerns and Vulnerabilities While DJI drones have proven to be valuable tools in public safety, their security vulnerabilities have become a point of concern. Several reports have identified weaknesses that could allow users to modify crucial drone identification details, such as serial numbers, and even bypass tracking security mechanisms. These vulnerabilities pose a significant risk to both drone operators and the public.
Recent Event: Chinese Drone Ban in Florida In response to these security concerns, some jurisdictions have taken action. Florida recently enacted a ban on Chinese drones, further highlighting the need for secure drone solutions in the public safety sector. This move underscores the importance of addressing these vulnerabilities to maintain trust in the growing drone industry.
DroneSense's Solution DroneSense, a company specializing in drone software, hardware, and professional services for first responders, has developed a new communication device to help mitigate security concerns associated with DJI drones. This device pictured in Figure1 is designed as an add-on for public safety drones and prevents information leakage to the drone manufacturer.
Figure 1: Dronsesnse Module Mounted on DJI Matrice 300 Airframe
Key Features of DroneSense's Device Referecing Figure 2, the new communication device offers several security and operational features, including First Responder traffic prioritization, 4G/5G data connectivity, secure real-time live streaming, and end-to-end 256-bit data encryption. By implementing these features, DroneSense aims to provide public safety agencies with a more secure and reliable drone solution.
Figure 2: Dronesense Features
Device Mounting and Compatibility DroneSense's communication device securely mounts to the airframe of various drone models using industrial-grade fasteners. This secure attachment ensures compatibility and reliability during flight operations.
Benefits for BVLOS Flights and More The device offers several benefits for beyond visual line of sight (BVLOS) flights, altitude limits, no-fly zones, and emergency landing sites. By leveraging 4G/5G networks and adding onboard intelligence, the device can improve the safety and functionality of public safety drone operations.
DroneSense's Commitment to Data Security DroneSense remains dedicated to supporting public safety and first responders while addressing security concerns. Their new communication device, compatible with multiple drone hardware devices and planned for expansion to non-drone platforms, is expected to be available in late 2023.
Conclusion The growing importance of drone technology in various industries highlights the need for secure and reliable solutions. DroneSense's new communication device addresses security concerns associated with DJI drones and offers a promising solution for public safety agencies. For more information, visit the DroneSense website at discover.dronesense.com/onboard.
Overview Photogrammetry holds a vital position in Unmanned Aerial Systems (UAS), facilitating the development of precise 3D point ckouds and maps using aerial imagery. This blog post concentrates on the optimal computer specifications for operating Pix4D photogrammetry software, a prevalent option within the industry. Alternatives such as Agisoft PhotoScan, DroneDeploy, and Bentley ContextCapture will be mentioned. Below is a table I created that beiefly categorizes different tiers of computer considerations which can help process data derived from photogrammetric UAS operations.
Table: Tiers of Computer Systems for Photogrammetric Processing
Considerations In addition to the specifications mentioned in the table, remember to consider additional features such as remote desktop connection access, portability, durability, and CPU protection while selecting a computer for UAS photogrammetric projects. While Pix4D is the primary focus of this guide, other photogrammetry software options have similar requirements. Agisoft PhotoScan, DroneDeploy, and Bentley ContextCapture all demand powerful processors, ample memory, and dedicated graphics cards to function effectively. However, there may be some differences in terms of compatibility and performance with specific hardware components.
Conculsion Selecting the right computer for photogrammetry software in Unmanned Aerial Systems depends on your budget, performance requirements, and additional features like remote desktop access and portability. The three tiers presented in this guide should provide a solid starting point for your search. Remember to consider your specific needs and the demands of the software you plan to use, and invest in a computer that meets or exceeds these requirements to ensure smooth operation and optimal results.
Photogrammetry is a technique used to derive accurate measurements and create detailed 3D models of real-world objects or landscapes by utilizing multiple photographs. The advent of Unmanned Aerial System (UAS) technology has significantly increased the importance of photogrammetry, especially when executed correctly with specialized photogrammetry software. The aim of this post is to review essential photogrammetry terms that are commonly used in Pix4D, but can also be applied to general UAS photogrammetric operations.
Photo Overlap Referecning Figure 1, photo overlap is the amount of shared area between adjacent images captured during a drone flight plan. Adequate photo overlap is crucial for ensuring that photogrammetry software can accurately stitch images together. Generally, photo overlaps between 60% and 90% are considered suitable. However, the ideal value can vary depending on the type of area being captured. For instance, when using the Zenmuse X/7 sensor from DJI, I typically aim for an 80% overlap especially since most of the envorinments that I capture include moderate to heavy vegetation. It's important to note that high photo overlap may become less effective and more time to process, but this can also depend on the specific circumstances.
Figure 2:Example of Photo Overlap
Geometry Geometry is the study of shapes, sizes, and positions of objects in space. In photogrammetry, geometry plays a crucial role in determining items such as camera gocal length, image orientation, image mtching, triangulation, surface reconstruction, and coordinate system transformation . Drone images captured at different perspectives are used to reconstruct the geometry of the scene, ultimately producing a 3D model. Referencing Figure 3 is an example of a colinear characteristics from geometry.
Figure 3: Colinear characteristics from geometry
Radiometry
Radiometry is the science of measuring electromagnetic radiation, including visible light. In photogrammetry, radiometry is essential for capturing accurate color and brightness information from images. The radiometric quality of an image affects the accuracy and quality of the final photogrammetric product. Radiometric corrections are used to remove inconsistencies caused by variations in the intensity of light, atmospheric conditions, and other factors that can affect the quality of the images. This is particularly important when using photogrammetry to create 3D models or maps of large areas because any inconsistency in the images can result in errors in the final product. See Figure 4 for a radiometry diagram
Figure 4: Radiometry Diagram
Triangulation
Referenced in Figure 5, triangulation is a process in which the position of a point is determined by measuring angles from known reference points. In photogrammetry, triangulation is used to determine the position of objects in 3D space using overlapping images. This process is crucial for creating accurate and detailed 3D models and maps.
Figure 5: Triangulation
Internal and External Parameters
Depicted in Figure 6, internal parameters refer to the characteristics of the camera used to capture images, such as focal length, sensor size, and lens distortion. External parameters include the position and orientation of the camera relative to the object being photographed. Both internal and external parameters are crucial for accurate photogrammetric processing.
Figure 6:Internal Pararmaters
Initial and Computed Parameters
Initial parameters are the approximate values of internal and external parameters, typically estimated using metadata from the drone and camera. Computed parameters are the refined values obtained through photogrammetric processing. Accurate computed parameters are essential for generating high-quality 3D models and maps.
Real-Time Kinematic
(RTK) is a GPS-based technology for UAS (Unmanned Aerial System) operations. By utilizing a network of reference stations, it corrects the GPS signal errors in real time, enhancing positional accuracy to centimeter levels. RTK enables precise navigation, improves flight stability, and increases the efficiency of UAS operation. The technology also allows for safer and more reliable operations in complex environments. RTK typically costs more compared to traditional GPS systems. Click on the video below for a video summarizing RTK.
Post-Processed Kinematic
PPK, combines GPS data from both the drone and a base station, enabling precise determination of the drone's position during flight. The collected data is processed after the flight, correcting any errors and refining positional information. This results in high-precision maps and 3D models,. PPK's main advantage is its ability to deliver centimeter-level accuracy without requiring real-time data transmission.
Coordinate System
A coordinate system is a standardized method of representing the position of points in space. In UAS related mapping, coordinate systems are essential for defining the location and orientation of objects and images accurately. The Universal Transverse Mercator (UTM) and the World Geodetic System (WGS84) are commonly used coordinate systems in photogrammetry. The specific coordinate system used may vary depending on the location, but typically, I use the state plane coordinate system unless there is a request for something else. To learn more about coordinate systems, click on the video below.
Tie Points
Tie points are identifiable features that are visible in multiple overlapping images and depicted in Figure 7 which was taken from a point cloud I created using Pix4D. Photogrammetry software uses tie points to establish relationships between images, align them accurately, and reconstruct the 3D geometry of the scene. The quality and quantity of tie points are essential for generating accurate and detailed 3D models and maps.
Figure 7: Looking at Tie Points Note Number of Images Accociated With Green Ray
Ground Sampling Distance (GSD)
GSD is a measure of the distance between two consecutive pixel centers on the ground, representing the smallest object that can be distinguished in an image. Referenced in the video below at 9:30 lower GSD values indicate higher image resolution and detail. GSD is influenced by factors such as camera sensor size, focal length, and flight altitude.
Volume Measurement
A volume measurment used to estimate the volume of objects or features, such as stockpiles, excavations, or earthworks. By creating a 3D model of the object or area, photogrammetry software can accurately calculate the volume, providing valuable data for project planning and management. Figure 8 depictes a volume measurement taken by data I captured with the DJI M210 Zenmuse X/7.
Figure 8: Example of Volume Measurment of Point Cloud
Absolute Accuracy
Absolute accuracy refers to the degree of closeness between the measurements or positions derived from photogrammetric processes and their true or actual values in the real world. In other words, it is a measure of how accurately the photogrammetric data, such as point coordinates or feature measurements, represents the true physical locations of the objects or features being measured.
Relative Accuracy
Relative accuracy measures the consistency of distances, angles, and positions between objects within the photogrammetric model. High relative accuracy is crucial for creating accurate 3D models and ensuring that the spatial relationships between objects are maintained. To reinforce the concept of absolute and relative accuracy, refere to the video below.
Structure from Motion
(SfM) is a photogrammetric technique that reconstructs 3D structures from a sequence of 2D images by analyzing the motion of the object or camera. It involves feature extraction, matching, camera pose estimation, and point cloud generation to create an accurate 3D mode. For a great explanation of structure from motion, visit the video below.
Root Mean Square Error
(RMSE) which is depicted in Figure 9, is a statistical measure used to quantify the average deviation between predicted and observed values. In the context of Unmanned Aerial Systems (UAS), it assesses the accuracy of measurements like position or elevation compared to ground truth data. Lower RMSE values indicate better accuracy, while higher values suggest larger discrepancies between the UAS measurements and the reference values.
Figiure 9: Note RMSE
Ground Control Points
Referenced in Figure 10, (GCPs) are easily identifiable, well-defined, and accurately surveyed reference points on the Earth's surface that are used to improve the geolocation accuracy and precision of aerial imagery captured by drones or other remote sensing platforms.
Figure 10: Example GCP Targets
Digital Elevation Model
(DEM) in UAS is a digital representation of the Earth's surface or terrain that is created using elevation data collected by aerial sensors mounted on unmanned aerial vehicles (UAVs), It displays the elevation information as a grid of cells where each cell corresponds to a specific area on the ground and has an associated elevation value. A DEM can include above ground features. See Figure 11 for details.
Digital Terrain Model
A DTM is a specific type of DEM that focuses on the bare ground surface, excluding above-ground features.
Digital Surface Model
A (DSM) in the context of refers to a 3D representation of the Earth's surface that captures both natural and man-made features, including buildings, vegetation, and terrain. See Figure 11 for details.
Figure 11:Difference Between DSM, and DTM
Conclusion
By comprehending this list of terms, you will gain a deeper understanding of the quality of photogrammetric data derived from Unmanned Aerial System (UAS) technology. The terminology described is not limited to Pix4D users but is also relevant to general UAS photogrammetric operations. If you think there are any additional terms that should be included, please feel free to share your suggestions.
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