HAPS are electric unmanned aircraft that fly at high altitudes above busy commercial air traffic. They are enabled by solar power to stay aloft for weeks or months at a time. Their current missions include surveillance and providing internet.
Here are some examples:
Balloons are often used for missions that require 24-hour surveillance of the same area because they are usually tethered, thereby enabling nearly unlimited endurance.
Here are some examples:
Thermal sensors detect infrared radiation in the 7.5 - 13.5 nm spectral band. All commercially available thermal sensors meant for use on a sUAS use an uncooled Microbolometer as the sensing technology. This technology has inherently lower pixel resolution than standard imaging sensors. Higher pixel resolution imagers are typically heavier, liquid cooled, and export controlled. This limits their use to larger aircraft and budgets.
Here are some examples:
Hyperspectral sensors have the capability to capture many discrete bands of light. This is typically over 200 discrete bands. Traditionally used in astronomy or food production, hyperspectral imagers are ideal for identifying specific elements within a scene to determine the scene’s chemical composition. The same use is applied to manned and unmanned application of this sensing technology.
Multispectral sensors capture multiple bands of light by using an array of distinct imagers with accompanying filters. The distinction between multispectral and hyperspectral is blurry. Our distinction is multispectral sensors consist of an array of multiple sensors capturing five-ten unique bands of light, while a hyperspectral sensor is a single sensor that captures 100+ distinct bands of light.
Here are some examples:
A converted near infrared (converted-NIR) sensor is a modified variant of visual-RGB sensor. Converted-NIR sensors use a filter placed directly over the imaging sensor to block a certain band of light thereby allowing NIR light to be captured by the sensor. This is an inexpensive way to capture NIR light information, which is particularly valuable when assessing vegetation performance. Most vegetation reflects greater in the NIR band than any other and NIR reflectance is directly correlated with photosynthetic performance of the vegetation.
A visual-RGB, also known as electro-optical (EO), sensor captures visible light. For sUAS applications, this sensor is typically used for cinematic photography and the creation detailed point clouds and orthomosaics through SfM post-processing. One major limitation of this sensor is it relies on ambient lighting conditions to collect information. Without another light source, this limits the sensor’s use to the daytime in most cases.
Here are some examples:
This body of knowledge extends our current experience. If you would like to add to this section, please contact the administrator.
This body of knowledge extends our current experience. If you would like to add to this section, please contact the administrator.
Check out http://www.sarmap.ch/wp/ to learn more about satellite-based SAR.
Laser scanners (LIDAR) create high resolution digital point clouds by measuring the time it takes for a transmitted laser signal to be reflected from the sensor, to an object, and back to the sensor. A laser scanner is an active sensor; it produces its own signal and eliminates the need to rely on ambient lighting to produce usable data. This is a critical difference to the Structure from Motion (SfM) method.
