By Chris S. Sherwin, ASLA
The rise of consumer-friendly unmanned aerial vehicles (UAVs) have enabled landscape architecture firms to take advantage of new technologies and digital processing that have previously been out of reach. The growing availability of drones for designers makes the new book Drone Technology in Architecture, Engineering, and Construction by two landscape architects — Daniel Tal, FASLA, and Jon Altschuld, ASLA — a timely addition to any firm’s library.
The book enables a landscape architecture firm with little drone experience to understand step by how to work a drone and the opportunities and obstacles with owning and operating one. Tal and Altschuld have transformed a complex and obscure subject into accessible content. The book is meant to be read in a sequential manner: each chapter builds upon the other and offers resources for further study.
Tal and Altschuld begin the book by explaining the rapid transformation of UAVs from a military tool to hobby radio-controlled aircraft. Consumer-level drones enable design professionals and clients to better understand the environment from the bird’s eye view. Drones offer unlimited potential for imagery and photogrammetry within a 3D modeling environment and are an important tool for communicating how a proposed design can impact sites.
The risks and shortfalls of drone technology are outlined through an exploration of the difference between good looking data and good data. With new low-cost drones, site scanning often involves just pressing a couple of buttons on an app and setting the site parameters. A user can produce a very detailed and good looking data set without understanding how these technologies function. This can be a hindrance to producing good data.
A new drone user needs to understand that producing a precise and correct data set involves a deeper understanding of drone technology, surveying, and photogrammetry processing. An accurate model requires knowledge of how to set ground control points, provide specific camera angles in relation to the site being surveyed, and set a steady and continuous ground sampling distance from the site as the drone surveys the property. Fortunately, all of these areas are thoroughly covered by the authors.
The book further explores how to effectively use drone data visualization as a project life-cycle tool. Chapters explain the costs necessary for staff training, examinations, and certifications; purchasing an appropriate drone; the software needed for flight, video and photo recording, photogrammetry; and insurance prior to your first flight.
Documentation, permissions, and licensing are also explored in-depth. The authors review the legal rules pertaining to consumer and commercial drone operations. Most importantly, they cover the Small Unmanned Aircraft Rule, which is known as 14 CFR Part 107, or in industry parlance the Part 107 exam. This exam is a crucial step in becoming a full-fledge drone operator in the design professions. Another vital step before becoming a commercial operator is understanding the permissions required through the Low Altitude Authorization and Notification Capability (LAANC) system, which allows for a relatively quick and seamless on-line process to gain permission before flying on site.
Proper documentation needs to be carried at all times. These documents include insurance certificates, your remote pilot license (Part 107), UAS registration, and a log of your flight operations. This documentation is key should something go wrong during your flight, and it is always a good rule of the thumb to be prepared for the worst case scenario.
Through the book, readers will gain an understanding of best flying practices, which many will gain with experience over time, and the importance of an appropriate safe flying mindset, such as developing a procedure for flight operations prior to, during, and at the conclusion of the flight. Situational awareness is key as well as proper flight procedures during manual and automated flying.
Tal and Altschuld explore basic drone photography, which many drone operators will use in the beginning of their flying career since it is relatively straightforward. Plus, the photographic results can be easily adjusted in commonly available Adobe Acrobat or Bluebeam software. Photo match overlays of the proposed project can easily be inserted into the existing site using Photoshop. 3D model photo overlays can also include integrating 3D modeling software models of the proposed design into the existing drone photography. This is a great tool for project visualization and client presentation meetings in which drone visualization images help communicate complex ideas easily and efficiently.
Chapters on photogrammetry and 3D modeling are the most crucial, because these tasks will ultimately provide the most comprehensive data needed for advancing complex design projects. The catch is that photogrammetry, although simple in concept, is a relatively complex process that requires time and patience. The first-time drone user needs to make sure that the data acquired is consistent and free of bugs; otherwise, the end result – the 3D mesh point cloud — will be rife with topographical errors, and the resulting model will be inaccurate and not suitable for using as a 3D Mesh in Sketchup, Autodesk Revit, or ReCap.
Precision and patience are necessary to produce a highly refined and detailed 3D point cloud. The author explain the steps required for an accurate on-site scan, such as establishing ground control points, proper flight, image collection, and weather planning. These methods require further study and a trial period of trouble shooting. The drone user will most likely produce several versions of a photogrammetric model before arriving at a finished product.
Drone Technology in Architecture, Engineering, and Construction is well-written and concise enough that the reader will not get bogged down with the details but still be engaged throughout the process. It is perfect for landscape architecture firms seeking to purchase a drone but are unsure of next steps.
Chris S. Sherwin, ASLA, RLA, is managing director and drone mapping expert at CSS D/S LLP in Oakland, California and Ulaanbaatar, Mongolia.