Manned vs. Unmanned: The 5 Criteria to Decide Which is Best for Your Aerial Project

Author: Joey Desjardins, Account Manager, AeroTech Mapping

Let’s start with something you probably weren’t expecting to hear from someone who works for an Aerial Mapping company.

Every surveying firm should own a drone.

They enable you to conduct site reconnaissance, perform inspections, and capture orthophotos to help you provide robust deliverables. This makes it easier for both the office staff and clients to understand the data vs. dots and lines with point codes and surface models on a black screen.

There are a wide variety of options for whether you’re getting your first drone, such as the DJI Mavic 3 Enterprise, which starts at $3,700 (up to $8,000 with RTK and D2 RTK base, or save $3,600 by pairing with your internet base capable GNSS), to mid-tier options like the $34,000+ M350 with P1 and L2 (45MP camera and 1.2MM points per second LiDAR sensor) or fixed wing options such as Quantum Systems’ Trinity Pro with the Sony RXI RII camera and Qube 240 LiDAR sensor for about $86,000 for those more proficient, and even $100,000+ rigs with advanced sensors for companies going all in.

The key, however, is determining which mapping missions are suitable for self-performing with a drone vs. hiring an aerial mapping firm with manned aircraft. We’ll explore the five key criteria to help you decide which approach best suits your project needs: flight restrictions, schedule, scope and capabilities, cost, and convenience. Additionally, to keep things light, I’ve included some AI generated art proving, while cool, AI isn’t quite ready to take over (tough to do when it has a hard time spelling).

Flight Restrictions

One of the primary considerations when choosing between drones and manned aircraft is the airspace over the project location. Drones are subject to a myriad of restrictions that can limit where they can operate. For instance, flying drones in controlled airspace, such as near airports (Class B, C, D, & E airspace depending on the size of the airport and traffic), requires Air Traffic Control (ATC) approval which can be obtained through Low Altitude Authorization and Notification Capability (LAANC). This could be a lofty task depending on the specific location and proximity to runways. Other sites such as military installations, and critical infrastructure sites, including nuclear power plants and chemical facilities can be nearly impossible due to strict regulations. Additionally, drones are not allowed in national parks, or wildlife refuges (due to safety concerns and wildlife protection) without approval of the Superintendent or a Special Use Permit (typically given for search & rescue, research, or fire safety). Both of which are highly unlikely to obtain.

While it is possible to obtain special permissions for some of these areas, the process can be complex and time-consuming. Manned aircraft, on the other hand, generally face fewer restrictions and mainly just requires communication and approval from ATC during the flight. This allows manned aircraft to be a better option for projects in areas where drone access is heavily restricted or unfeasible.

When working on federal projects, drone approval often depends more on the hardware and software than the airspace itself. Before conducting drone operations for federal agencies, it’s crucial to understand two key compliance standards: the National Defense Authorization Act (NDAA) and the Defense Innovation Unit’s (DIU) Blue sUAS Cleared Drone List (Blue List).

The NDAA sets forth regulations to ensure the security of the U.S. defense supply chain, particularly concerning Unmanned Aerial Systems (UAS). Specifically, Section 848 of the Fiscal Year 2020 NDAA prohibits the Department of Defense (DoD) from procuring drones manufactured in a “covered foreign country” (notably China) or those containing components like flight controllers, radios, data transmission devices, cameras, gimbals, ground control systems, or operating software from these countries or companies based in these countries. In 2022, Congress updated the list of countries to include Russia, Iran, and North Korea. This has also been extended to the private sector working under federally funded contracts. This compliance ensures that drones used for and by federal agencies are free from potential foreign interference or data security risks.

The DIU’s Blue List is a subset of NDAA-compliant drones, hardware, and software specifically verified by the DIU to meet NDAA compliance and assessed to meet the DoD’s cyber security requirements, such as being completely offline. Drones on this list undergo comprehensive evaluations to ensure they are secure, reliable, and suitable for military use. The Blue UAS program streamlines the approval process, allowing military units to rapidly deploy trusted drone technology without compromising security. Blue List is not explicitly required for DoD purchase. However, products on the Blue List do not require an Exception to Policy (ETP) and are updated more frequently than traditional Programs of Record (POR), making them much easier to be approved for purchase and use on DoD projects. You can find the products on the Blue List on the DIU’s website.

A new initiative is the Association for Unmanned Vehicle Systems International’s (AUVSI) Green UAS Certification, which serves as a pathway for drones that are not yet Blue UAS certified but meet initial security and compliance benchmarks set by the DoD. This list allows commercial drone manufacturers to demonstrate their security measures and capabilities before undergoing the full vetting process for the Blue List. While there are no specific agencies requiring Green List products, manufacturers with this certification are better positioned to gain future Blue List approval.

Schedule

In some cases, self-performing with a drone can offer a significant advantage in terms of flexibility and timeline of acquisition. Drones can be deployed as soon as you’re on-site, allowing for rapid data collection and potentially quicker turnaround times for projects with urgent deadlines. For simpler projects, processing and mapping can often be completed in just a few days after the flight.

Manned aircraft, however, typically have a longer lead time. For example, AeroTech Mapping can have a plane scheduled to be on-site as fast as 48 hours from receiving the Notice to Proceed (NTP) or within one week at the latest. Smaller projects tend to be delivered 10-12 business days after a successful flight and receipt of control. Aerial Mapping firms with more dedicated resources and expertise tend to have faster turnaround times on larger, more complex projects than the turnaround times of firms with smaller, less experienced teams.

Weather conditions also affect scheduling. Drones are less susceptible to weather-related delays, such as winds at higher altitudes or low-altitude cloud coverage. They are, however, much more susceptible to winds at low altitudes. The Mavic 3E and WingtraOne have a maximum sustained wind tolerance of just under 27 mph while flying (19 mph on the ground during takeoff and landing for the WingtraOne). Neither drones nor manned aircraft are able to complete aerial mapping missions in severe weather like rain and fog. Additionally, drones are only affected by the weather on-site, whereas manned aircraft are affected by the weather where the aircraft is stationed and the weather en route to the project site. The weather at a project location could be perfect, but if there are 30 mph winds at the airport or a rainstorm between the aircraft and the project, the site will not be flown that day.

Scope and Capabilities

What are the required deliverables for your project? What is the size of the area of interest? The scope of your project and the capabilities of your drone can be the deciding factor on whether to self-perform or partner with an aerial mapping firm. Drones are well-suited for high-resolution imagery, given they fly at much lower altitudes (sub 400ft AGL vs 1,500-4,000ft AGL). The sensors used and altitude flown by manned aircraft are capable of producing imagery with Ground Sample Distance (GSD) as tight as .15’. Projects requiring tighter GSD are better suited for drones. This is also why the size of the project impacts the decision to use a drone or a manned aircraft. Drones have varying flight times and camera sensor qualities. Drones carrying cameras with lower megapixels (Mavic 3E – 20mp) need to fly at a lower altitude than ones with higher megapixels (Quantum Systems Phase One P5 – 128mp) to capture the same GSD. Lower altitudes mean less coverage, more aerial control panels (due to more images to be tied together), and more airtime. Larger project sites with a lower quality camera will take much more time to fly. Each system has its own project size threshold where manned aircraft would be a better fit.

Not only is there a relationship between the size of the project and the camera specs when determining which is best for an aerial mapping project, but also the battery specs of the drone. Each platform’s specifications include a flight time and the approximate area it can cover in a single flight. For example, the Mavic 3E RTK has a flight time of 45 minutes and boasts a single flight survey area of a tad short of 500 acres in a single flight (20MP camera, and 5cm GSD with 80% front and 60% side overlap at 15m/s). A fixed-wing drone such as the WingtraOne MAP has a maximum flight time of 59 minutes, can capture the same resolution at a higher altitude because of its 61MP camera, a slightly higher rate of speed (16 m/s), and covers up to 1140 acres in a single flight (890 acres with LiDAR flown separately from photography). In addition to the field time determined by the size and capabilities of the drone, office time increases due to the number of images to be processed and mapping to be compiled. Each system has a threshold where manned aircraft is more cost-effective. This is determined not only by the drone specifications but also by the capabilities of the firm processing the data and generating the deliverables (not to mention the specifications of the computers handling the processing and mapping).

Both are well suited for design scale mapping (typically 1” = 40’ scale with 1’ contours). Manned aircraft are able to efficiently capture data suitable for mapping scales starting at 1” = 10’ and contours at tight as .5’. Projects requiring tighter scales or contours are better suited for drones.

Some projects go beyond the typical aerial mapping deliverables. Select drones provide payload flexibility, giving users the ability to capture all sorts of data, such as thermal, video, and oblique imagery, that wouldn’t otherwise be captured by manned aircraft.

One payload option available both to select drones and manned aircraft is LiDAR (Light Detection and Ranging). LiDAR sensors produce millions of points per second via a refracted invisible laser beam that results in a point cloud of the area of interest. LiDAR sensors with multiple returns are also able to penetrate through varying levels of vegetation, which gives more accurate ground elevations in areas where the ground isn’t visible in the imagery. They also provide more accurate vertical data on hardscape vs traditional photogrammetry. Entry-level drones tend not to have LiDAR capabilities like mid-tier and high-end systems. Projects with LiDAR requirements, or those that could benefit based on the terrain/vegetation, may be better suited for manned aircraft depending on the configuration of the drone hardware owned by the surveying firm.

Cost

Controlling cost is a key factor in not only being selected for a job but also in the profitability of the job. Selecting the right approach will help win more projects and help complete them in a profitable manner. The costs associated to the flight portion tend to be similar across project sizes under 500 acres as most commercial drones can cover large areas in a single flight as discussed above. The difference in the field & acquisition cost lies in the amount of ground control targets/photo ID points collected and the time to generate the deliverables.

Let’s look at a breakdown of a 5-acre commercial site rich with detail such as parking striping, buildings, vegetation, etc. and what it would take to produce a Design Scale map (1” = 40’ scale, 1’ contours, DTM points and breaklines).

Unmanned Manned
Flight Time (including flight prep) <30 minutes 0
Panels/Time 5/2-3 Hours 5/2-3 Hours
Raw Data Processing 1-2 Hours 0
Deliverable Generation 6-8 Hours 0
Total Surveyor Hours 2.5-3.5 Field Hours, 7-10 Office Hours 2-3 Hours

If we use a billable field rate of $350 per hour and a billable office rate of $175 per hour (region specific), the unmanned approach would run about $2,100 – $2,975, including the billable survey fee of $700 – $1,050 to set panels. ATM charges about $2,500 – $3,500 for similar projects. In this case, self-performing with a drone would likely be more profitable than hiring an aerial firm.

Let’s use an example for the same type of site with the same deliverables but covering 40 acres.

Unmanned Manned
Flight Time (including flight prep) <30 minutes 0
Panels/Time 8/3-4 Hours 5/2-3 Hours
Raw Data Processing 2-3 Hours 0
Deliverable Generation 45-50 Hours 0
Total Surveyor Hours 3.5-4.5 Field Hours, 47-53 Office Hours 2-3 Hours

Using the same billable rates, the unmanned approach would run $9,450 – $10,850, including the billable survey fee of $1,050 – $1,400 to set panels. ATM charges about $5,000-$7,000 for similar projects. In this case, it could be more profitable, save the surveyor time, and potentially be a lower total job fee.

Keep in mind that Raw Data Processing and Deliverable Generation times vary based on a few factors. First, Raw Data Processing can occur after business hours. Second, the time can vary based on the computing power of the workstation/cloud processing service and the specific software used. Third, manual vs automated extraction workflows greatly impact the amount of processing time depending on the site, data quality, and the specific deliverables.

Convenience

The last criterion to consider when choosing between self-performing with drones or hiring an aerial mapping firm is convenience. Operating drones in-house provides greater control over timelines and execution. However, it also requires dedicating hours to flight planning, approvals, field time completing the flights, office time processing and generating the deliverables, detracting from other revenue-generating activities.

Subcontracting to an aerial mapping firm can alleviate these burdens and bring specialized expertise and resources to handle projects more effectively and efficiently.

In the example above, hiring an aerial firm on a 5-acre project gives the surveyor 4 – 8 hours back, which has varying levels of value depending on the surveyor’s workload. On the 40-acre project, the survey gets 44 – 51 hours back, adding over a week of productivity back to their life.

AeroTech Mapping’s Cloud to CAD Service

Even after considering each of these criteria, some projects may still fall between self-performing, and hiring an aerial firm. What if you have a tight flight window, can produce an Orthophoto and Point Cloud/Digital Surface Model (DSM), but don’t have the time or expertise to produce the deliverables? AeroTech Mapping offers a hybrid solution known as “Cloud to CAD”. In this scenario, clients self-perform the flight and handle the initial processing to produce the ortho and point cloud, usually within 24 hours of a successful flight. AeroTech then takes over to produce the deliverables with a turnaround time of 5-12 business days, depending on the project scope and expedited service.

This approach is particularly beneficial when tight flight windows or rapid turnaround times are required. It allows firms to leverage the advantages of both in-house operations and professional mapping services. Clients who opt for this method might choose it to meet urgent deadlines, achieve higher-resolution imagery, or manage an understaffed office with a backlog of tasks. The cost savings and efficiency of this model make it an appealing choice for many projects.

Mobile Mapping Cloud to CAD project

Conclusion

Choosing between self-performing an aerial mapping project with a drone or using your aerial partner depends on a variety of factors. Flight restrictions, project schedule, scope and capabilities, cost, and convenience all influence this decision. Drones offer flexibility, speed, and cost-efficiency for smaller or less restricted projects, while manned aircraft provide a broader operational range and specialized capabilities for larger or more complex tasks. AeroTech’s Cloud to CAD option presents a hybrid approach that can offer the best of both worlds. By carefully evaluating these criteria, your firm can make an informed decision that aligns with your project requirements and objectives, ensuring successful and profitable projects.

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