Glossary of Terms
Terms and definitions used throughout Canopy.
Capture Window
The period of time when the capture (collection) will occur. The actual collection itself (whose duration is called dwell time) is shorter than the capture window. Example: A capture window of 70 seconds may have a dwell time of only ~5-10 seconds.
Collect
Collects represent the radar parameters and geometry of a single imaging operation. Once a Task has reached a SCHEDULED state, one or more Collects are generated and are available to provide a more detailed view of the Task fulfillment as well as a visualization of the footprint.
Delivery Config
Specifies how and where your deliverables are delivered once a collect succeeds. Canopy supports delivery to AWS S3 Buckets or to Google Cloud Storage Buckets.
Feasibility
Feasibility is the process of evaluating your tasking parameters like Area of Interest, resolution, and geometry limits (e.g., grazing angle, target azimuth) against the current constellation schedule to determine when a satellite could fulfill your task request.
Footprint
The total area covered by your image; The size, on the ground, of the area captured. For example 5x5km or 100x8km.
Grazing Angle
The angle between the local vertical and the line of sight. It is a complement to the incidence angle (they always add up to 90 degrees). The grazing angle plays a pivotal role in determining the radar's viewing angle, directly influencing the steepness or shallowness of the radar's approach.
Ground Range
The shortest distance along the earth’s surface between the center of the collection and the spot on earth that is directly beneath the satellite at the time of collection. Similar to Slant Range, except that Slant Range is measured from the satellite whereas ground range is measured from a point on earth directly below the satellite.
Incidence Angle
The angle between the tangent to the surface and the line of sight. It is a complement to the grazing angle (they always add up to 90 degrees.)
Imaging Mode
Imaging Mode specifies how the satellite collects data for your request. Currently, Umbra offers Spotlight and Scan as Imaging Modes.
Opportunity
An Opportunity is a specific time window on a specific satellite, returned from a feasibility request, during which your task’s constraints (resolution, time window, geometry) can be satisfied. An Opportunity is used to populate a Task request.
Orbit Direction
Indicates whether the satellite is traveling south to north (Ascending) or north to south (Descending) during the pass.
Multi-looking
Multi-looking is a technique used to enhance image quality by reducing speckle noise, which is inherent to radar images. This process involves averaging multiple looks, or observations, of the same target area taken from slightly different angles. By averaging these looks, the random speckle noise present in each individual image can be significantly reduced resulting in data which is easier to interpret and analyze.
Polarization
Polarization in SAR refers to the orientation of the radar wave as it interacts with the Earth's surface and is a crucial parameter for enhancing the interpretation of surface features. Currently, Canopy offers VV and HH polarization. See our full guide.
Resolution
The ground plane resolution of the collect. Essentially, the higher a resolution, the greater its ability to distinguish finer details, allowing for more precise differentiation between various features or data points within a single collection.
Satellite ID
The identity of the Umbra satellite used for a collect. For example, Umbra-06. For more information on how Satellite IDs are displayed, please visit Umbra Satellites.
Scan
A type of Imaging Mode, Scan is designed for wider area coverage and supports long continuous strip imaging (up to 100 km) which is configurable by resolution (0.5m, 1m, 2m).
Scene Size
The on‑ground dimensions of the delivered image (e.g., 5 × 5 km), defined by the product type and processing.
Slant range
The distance between the radar transceiver and the area of interest.
Spotlight
A type of Imaging Mode, Spotlight provides high‑resolution coverage at a guaranteed minimum footprint of 5x5km, with options for larger scene sizes depending on your organization’s settings.
Squint Angle
As of September, 2024, the Canopy app now uses Umbra's engineering definition of squint as its default:
The radar's direction relative to its path of travel directly ahead (the velocity vector) is marked as 0° ranging from -180° to 180°.
For API users, Canopy's previous squint definition with directly ahead marked as 90° is still available. See more details here.
Swath Width
The cross‑track width of the surface imaged in a single pass or collect. It is determined by imaging mode, and is fixed to 8 km for Scan collects.
Target Azimuth Angle
The target azimuth angle refers to the angle between true north and the line from the observer (in this case, the satellite) to the target, measured in a clockwise direction on the Earth's surface. It plays a crucial role in defining the orientation of the satellite relative to the target area. See our full guide.
Task
A Task represents a request for new data to be collected by the Umbra constellation. Tasks are composed of the geolocation to be imaged, the desired timeframe, the image collection mode, and geometric view constraints.
Updated 21 days ago