The Fixed-Wing Aircraft of Aerial Surveying & Mapping

Even though both manned and unmanned rotor-wing aircraft are heavily used in Aerial Surveying & Mapping, the majority of such surveying & mapping is conducted by both manned and unmanned fixed-wing aircraft. In recent years, fixed-wing aircraft have increasingly been used to conduct aerial surveys due to their adaptability with newer sensors, range, endurance, and economics. These benefits have allowed aerial surveyors to capture large quantities of high-resolution geometric/photographic data. In some ways, only possible from a "birds-eye" perspective. 

With an array of advantages, aerial surveying & mapping professionals are just not focused on helicopters and Unmanned Aerial Vehicles (UAV) or drone aircraft to get the job done. Instead, they rely on fixed-wing aircraft to perform various surveying tasks, from ultra-high-definition spot imagery to wide area mapping. 

Undoubtedly, fixed-wing aircraft deliver time-tested advantages. So, how are fixed-wing aircraft used in aerial surveying & mapping? The best way of answering this question is – What is aerial surveying & mapping, and how do fixed-wing aircraft and the crews fly these airplanes to accomplish their task?

What is Aerial Surveying & Mapping? 

Aerial surveying & mapping is the practice or profession of gathering data that uses aerial vehicles to acquire images or data via photography or remote sensing, i.e., capturing the various electromagnetic spectrum bands, such as infrared, gamma, or ultraviolet. In other words, it is the method of detecting and observing the physical characteristics of an object by measuring it's reflected or emitted radiation at a distance. Aerial Surveying & Mapping is applied especially to acquiring information about the world. The data collected by Aerial Work fixed-wing aircraft are used in numerous fields, including: 

• Scientific Research
• Military & Intelligence
• Commercial
• Humanitarian
• And many more

In aerial surveying & mapping, the purpose is to obtain a complete and accurate image of assigned points and areas on the earth's surface. Some of the various methods for obtaining this data are:

• RADAR – RADAR (Radio Detection and Ranging) imaging involves using sensors to collect data through radio waves. 

• Multispectral – Multispectral sensing enables the analyst to see all light wavelengths. This method allows for seeing through clouds and other obstructions that would otherwise hide information from the eye. 

• LIDAR – LiDAR (Light Detection and Ranging) is a form of mapping that uses light pulses or laser beams to collect 3D images. 

• Aerial Photography- Compared to the other collection methods, photography involves taking images with a photographic camera and processing that data later. 

The kind of information gathered by aerial surveying & mapping operations can vary based on the needs of the individual who employs the survey. For example, aerial surveying & mapping projects routinely collect data regarding:

• Tracking large forest fires from the air allowing land managers and firefighters to see a much larger area than from the ground. 

• Following changes in a city's urban areas, farmlands, or forests over several years or decades. 

• Supporting major infrastructure projects, e.g., office buildings, highways, etc. 

Regarding the contracting source or end-users of this data, the users are primarily private non-aviation companies, government agencies, and public organizations. Their primary need is usable data supporting their specific interest and projects. In the case of fixed-wing aircraft, it's a need for accurate "bird's eye" broad area information about their area or spot of interest.

What are the Types of Applications? 

Concerning fixed-wing aircraft conducting aerial surveys, the best approach to collecting geometric/photographic data is by fusing sensors such as RADAR, LIDAR, and digital cameras with satellite navigation units (GPS/Galileo) installed on a specialized or configured aircraft. When mixed with the newest presentation tools, such as 3D photogrammetry and 3D LIDAR mapping, the results are extremely useful and effective for the purpose of the aerial surveyors and the users of such information. 

As mentioned before, fixed-wing aerial surveying & mapping companies focus on many types of aerial surveying & mapping applications. However, to give a better perspective of the types of surveying & mapping this sector accomplish with fixed-wing aircraft, here are several types of missions better suited for fixed-wing aircraft: 

Agricultural Mapping – Fixed-wing agricultural mapping supports large agriculture producers, small farmers, and many other agriculture-environmental organizations in managing many critical functions and daily issues facing farmers and ranchers. Fixed-wing aircraft provide the range and endurance to survey – with a wide range of sensors – an entire farm or rangeland in a short period. The data from these surveys facilitate the agriculture sector in managing irrigation, fertilizer levels, and even tracking livestock in remote ranch areas. 

Emergency or Disaster Management Mapping – Fixed-wing surveying & mapping capabilities are growing in the emergency management sector. Their use in reducing vulnerability to hazards and coping with disasters have been critical in saving lives and property, e.g., assessing damage and monitoring refugee migration. Fixed-wing aircraft provide quick response over long distances to survey the situation from above without interfering in rescue and recovery operations. Besides assessing after or during an emergency, fixed-wing aircraft help assess the potential of an emergency. 

An excellent example of this is "Hurricane Hunters." Hurricane Hunters fly specialized Lockheed C-130 Hercules and Lockheed P-3s and even convert executive jets to fly into or over hurricanes (tropical cyclones) to monitor the characteristics of a storm and report their findings to national weather centers around the world. 

Geographic Mapping – Fixed-wing geographic surveying & mapping operations involve taking measurements of geographical areas to support numerous academic and practical environmental purposes. For example, the information from these surveys supports seismology and geology studies, along with land maintenance projects. Furthermore, aerial fixed-wing surveys are used to assess the damage caused by forest fires and the erosion of topsoil areas along waterways and streams. 

Construction Mapping – Regarding the infrastructure of society, fixed-wing aircraft mapping & surveys are used at each phase of many major construction projects, e.g., a new highway, bridge, industry park, or gas pipeline. With the appropriate sensors and data processing systems, fixed-wing aircraft provide the means to acquire from the same vantage point (coordinates & altitude) the initial dimension of a construction site to regular progress reports throughout the life cycle. 

The fixed-wing Aerial Work surveying & mapping industry provides high-density, accurate resolution remote sensing datasets that achieve survey-grade accuracies for engineering design and as-built documentation. Besides just "flying the line," most aerial surveying & mapping service providers work with their clients during the project planning phase to ensure they thoroughly understand their client's project requirements. Once the requirements are identified, a Collection or Project Manager coordinates with the client's team to determine the best approach, technology, platform, and resources to achieve the project goals. 

When it comes to the platform, i.e., fixed-wing aircraft, the selection of the aircraft is primarily made based on the sensor payload requirement and the time & distance required to collect the desired dataset. In addition, other operational considerations must be considered, such as airspace access, usable airfields, life support for the aircrew, and many more. 

On the technology side of the decision matrix, the Collection Manager and clients' planning team will decide on the right technology or sensor(s) to accomplish the task. In this case, they will probably ask these types of questions to develop the right solution: 

What type of sensors are required? – Based on the project requirements, the choice can be a multispectral, near-infrared, thermal, laser, radar, hyperspectral and more. In many cases, these single technologies or capabilities can meet various objectives independently.

Is a single sensor the best solution? – Single sensors like LIDAR scanning platforms are closely coupled with HD image sensors where data is obtained in both the visible and non-visible electromagnetic spectrum. Single sensor operations minimize a collection operation's " footprint " and reduce cost. However, single-sensor operations might require multiple passes if other datasets are required, i.e., the aircraft needs to be reconfigured with a different single sensor. 

Is a multiple sensors configuration the best solution? – Multiple sensor operations can be configured for acquisition during a single flight or efficiently develop high-value, multi-purpose products. Unlike single-purpose mapping sensors, multi-sensor configurations can collect multiple HD datasets simultaneously, reducing the need for multiple aircraft. Additionally, this can minimize mobilizations of crews and flights, allowing faster data collection, reducing operational activities, and possibly reducing overall project costs. 

Following the flying portion of a project and to effectively complete an aerial surveying & mapping job, many aerial surveying & mapping service providers provide post-flight data processing and distribution services. Usually equipped with advanced IT infrastructure, these firms use current industry data processing, filtering, and distribution technologies to support such procedures. With this, they can quickly deliver terrain and above-terrain datasets, 3D features, and identify anomalies using semi-automated feature extraction methods.

What are the Pros and Cons of Using Fixed-Wing Aircraft? 

Regarding the Pros & Cons of using a fixed-wing aircraft for aerial surveying & mapping, the answer lies in the unique capabilities these aircraft provide. Fixed-wing aircraft provide specific abilities that other types of airplanes (rotor and balloon) cannot provide. 

While the actual surveying equipment may be separate, the airborne platform from which the data is captured will significantly impact the cost of the survey and the accuracy of the collection. Therefore, here are some pros and cons of using a fixed-wing aircraft in relation to rotor-wing and small drone aircraft.

• Weather - High winds, rain, and low visibility can quickly ground a rotor-wing and small drone aircraft. However, fixed-wing aircraft are more tolerant to many weather phenomena (e.g., high winds, low ceilings, etc.). 

• Range – Fixed-wing aircraft also have a more extended operational range than rotor-wing and small drone aircraft, plus they're faster (depending on the platform). Better range means you spend more chargeable time on the target than en route to and from the collection area. 

• Payload – Depending on the platform, fixed-wing aircraft can generally carry heavier and more types of systems vs. rotor-wing and drone aircraft. 

Regarding negatives, fixed-wing aircraft for specific aerial surveying & mapping is not always ideal. Some of the imperfect aspects are: 

• Lower – If the collection requirement is for low-level and slow coverage of spot targets, fixed-wing aircraft are not the best choice for such work. Helicopters can hover while integrated with large sensor systems, remaining stable even in bad weather over locations drones and fixed-wing aircraft can't operate. 

• Closer – Not like Helicopters and small drones, fixed-wing aircraft can't fly close and acquire high-resolution imagery of targets within confined or congested spaces.  

What are the Aircraft & Kits used in Fixed-Wing Surveying Operations? 

On the aircraft side, the aerial surveying & mapping service sectors primarily use light fixed-wing aircraft or aircraft with a max gross takeoff weight of 12,500 lb (5,670 kg) or less. Light fixed-wing aircraft provide the best performance and cost-effectiveness relative to carrying essential sensor systems onboard and providing the standard range/endurance required for surveying operations. 

To get a good perspective of the types of fixed-wing aircraft currently being used in this sector, here is a list of aircraft that are configured for aerial surveying & mapping and are available for lease or to buy: 

• Cessna T303 Crusader - With 20" camera hatch
• Vulcanair P68B Victor - With camera hatch
• Cessna T206H - With 21" camera hatch
• Piper Turbo Saratoga - With dual camera hatches
• SILA 450CF - With camera hatch • Cessna 208 Caravan - With dual camera hatch
• Diamond Aircraft DA42-VI – sensor platform with several sensor mounts 

On the kit side, the types of kit (sensors and systems) currently being used and traded within the aerial surveying & mapping sector are: 

• ADS100 (Digital RGB Digital Sensor) – GPS & IMU included
• Riegl LMS-560 (Leaser Sensor) – No recorder included • CC31 Camera Controller – Includes cables and connectors
• UltraCam Osprey Mark III (Photogrammetry camera) – Includes a docking station, recorder, and pilot display • GSM 4000 (Gyrostabilized mount) – Includes cables and connectors
• And many more… 

As you can see, fixed-wing aircraft are a vital part of the aerial surveying & mapping sector. However, if you think about it, no other type of aircraft can meet the specific requirements of collecting large amounts of data over vast distances in a timely and economical manner. 

Without a doubt, fixed-wing aircraft can safely survey large areas or inaccessible locations. In addition, with the ability to fly high and long, fixed-wing aircraft offer a perspective that other platforms can't. 

So, when you bring together the "time-tested" flying capabilities of a fixed-wing aircraft and leading-edge surveying sensors flown by highly trained aircrew and supported by a Geospatial Information System (GIS) specialist, you have a compelling capability. 

Therefore, if your work requires aerial surveying & mapping support, don't be surprised if a fixed-wing aircraft is the "Right Tool for the Task!"