Chapter 6

Remote Sensing in Precision Agriculture

Remote Sensing Platforms

Remote sensing platforms are defined as vehicles, such as satellites, aircraft, and unmanned aerial vehicles (UAVs) that can carry sensing devices to perform remote measurement operations. These platforms acquire images with different spatial coverage, spatial resolution, temporal resolution, operational complexity, and mission cost. These platforms are continuously improving in terms of operational time, reliability, simplicity, and temporal resolution (the time interval between successive remote sensing measurements), which affects the spatial resolution. With diverse options available with specific characteristics, choosing a suitable platform depends on the nature of the problem. Three critical factors for selecting the best platform are spatial resolution, farm size, and operation cost.

Satellite Remote Sensing Platforms

Space-borne platforms for remote sensing are considered to be the most stable platforms among all others. Space-borne platforms are categorized based on their orbits and timing. Unlike UAV platforms, which are a suitable solution when a “micro” view of the land is of interest, satellites provide a relatively low-cost “macro” view of the terrains that make them an efficient method for large-scale mappings such as desertification, land cover classification, climate change, and inter-field comparisons. As the literature suggests, vast areas can be mapped by satellite remote sensing, mainly for large-scale studies and monitoring, which makes it promising to extract extensive time-series data.

Manned Aircraft Remote Sensing Platforms

Manned aircraft often have a definite advantage because of their mobilization flexibility. They can be deployed wherever and whenever weather conditions are favorable. Aircraft on site can respond with a moment’s notice to take advantage of clear conditions while satellites are locked into a schedule dictated by orbital parameters. Aircraft can also be deployed in small or large numbers, making it possible to collect imagery seamlessly over an entire area in a matter of days simply by having lots of planes in the air at the same time. They are very efficient collectors of remote sensing data as manned aircraft can fly fast, travel long distances, land at any airport, refuel and keep flying, and carry well-stabilized and heavy sensors.

Unmanned Aerial Vehicle Remote Sensing Platforms

The application of unmanned aerial vehicles (UAVs) or drones, aircraft capable of flying autonomously or controlled by a remote pilot, has tremendous potential for acquiring aerial images because of the low operational cost, high temporal and spatial resolutions, easy-to-use controlling system, and high flexibility in image acquisition planning. With recent technological advances, the payload capacity of UAVs (colloquially known as “drones”) has increased substantially, allowing them to carry a variety of payloads (e.g., sensors, cameras, spray equipment) for various precision agriculture applications. Many growers refer to UAVs as Unmanned Aerial Systems (UASs), which reflects the complexity of systems onboard these vehicles.

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