Remote monitoring glossary

Any image taken from a point above the earth, such as a hot air balloon, drone or unmanned aerial vehicle, airplane or satellite.

A manned aircraft that flies over an area to capture images from the cabin windows or from a camera fixed to the body of the plane. Land trusts can pay companies for flight time or gain free access to time donated by pilots through nonprofit organizations.

Satellite imagery is used for the model because images are taken at a frequency necessary to detect change. There is a combination of spectral differences over time, from images captured daily, weekly or monthly, and changes are extracted through machine learning.

Displays the natural and human-made environment in a color gradient based on the collected vertical points (z) values from the images.

A type of spectral resolution that uses at least one non-visible light band to highlight aspects of the image that are difficult to see.

A balloon, manned or unmanned, that captures aerial images of an area. Balloons can provide imagery at a high resolution.

A type of spectral resolution that contains discrete light bands capable of identifying unique minerals, compounds, surface liquids, gases, pollutants, vegetation species and built materials. Hyperspectral imagery can highlight water or wet surfaces and show them in greater contrast to the surrounding environment as a gradient of blue. See example.

Leaf-on refers to the on the ground conditions that restricts the monitor’s view to the top of the canopy. These images are taken in late spring, summer and early fall.

Leaf-off refers to the on the ground conditions that allows the monitor to see through deciduous trees to the understory. These images are taken in late fall, winter and early spring.

Imagery that was requested by another customer and is then offered for resale at a lower cost by a provider.

A type of spectral resolution that will show paved, built or human-altered areas as white, with vegetation surfaces contrasting as a gradient of green and drier surfaces as a gradient of orange and red. See an example of LiDAR spectral resolution.

As opposed to “vertical” imagery that is shot from directly above the ground, oblique imagery is typically shot at an angle from an aircraft view. See example.

An image that takes multiple orthorectified images that are overlaying each other and stitches those images into one seamless image.

An image that has been formatted to show an even terrain by rectifying the distortion caused by the earth's tilt and the relief of the land. In this diagram, the perspective view is the raw image and the orthographic image is the orthorectified image.

This technology is used to detect changes in a landscape – an automated process that would otherwise have to be done by hand. Machine/deep learning detectors are trained to extract features that enable near real-time change detection and monitoring. The resulting files are then synced with GIS to allow for remote monitoring.

A spectrum of light not visible to the human eye that can be enhanced to show the differences between healthy and unhealthy and/or dead vegetation.

The difference between these two sensing types is the light source: passive sensing uses the sun, while active remote sensing uses its own light source and measures the amount of reflection returning to the sensor. An example of passive remote sensing is true color imagery, whereas LiDAR and SAR are active remote sensing. See an example.

A process of converting 2D images to 3D images using the elevation data within overlapping images.

The act of observing conditions on the earth from an image or video at a different location from the area of observation.

A broad term for acquiring and reporting data and imagery – including analytical tools, image viewing platforms and web-based data storage options that are typically offered on a subscription basis. While web-based platforms tend to be more user-friendly and often offer cloud storage to reduce data storage constraints on your organization, they sometimes have limited customization options.

A device orbiting the earth capturing images and other data from space. Satellites are operated by both national agencies like NASA or ESA and private companies like Planet. They have a variety of spatial, spectral and temporal resolution capabilities.

The measurement of the detail or clarity in an image. The level of resolution is determined by how much space on the image a single pixel represents, as measured by a number. A lower number, like 0.3m or 0.5m, denotes a higher resolution image and is known as finer resolution. A higher number, like 1m or 30m, denotes a lower resolution image and is known as coarse resolution. In this example, the finer resolution is on the left and the coarser resolution is on the right

Defines what types of sensors are used to detect non-visible light bands, as well as how the image has been altered after it was taken to better identify differences on the ground. The spectral resolution can show vegetation growth, existence of wet areas and waterways, drought conditions and paved or hardened surfaces. The number of sensors used to capture image data determines the types of terrain features that can be seen and at what image resolution differences on the ground are determined.

This is an active sensor, also known as persistent imaging, that can create an image at night or through cloud cover. The image will be rendered in black and white based on the concentration of radar returns, otherwise known as backscatter.

The process of a customer requesting imagery of a particular place at a particular time. Companies that manage these types of requests have different requirements for the minimum amount of area covered, timing and pricing. This image is an example of how one company tasks their satellites to capture images of a specific location on the globe.

How frequently data or imagery is captured. The frequency can range from daily to monthly to yearly. This graphic depicts how frequently popular satellites can capture imagery.

Unmanned aircraft that can capture images from either a pre-planned or impromptu flight path and are able to increase and decrease resolution level at the user’s command.