Accuracy: The difference between a result obtained and the 'true' value.
Along track: A path along the Earth's surface (corresponding to a satellite's direction of movement).
Channel: Spectral channel (S1-S9 + F1-F2).
Detector: Pixel array at band N.
Calibration: The process of quantitatively defining the system response to known, controlled system inputs.
Field-Of-View: The angular extent of a given scene that is viewed by the instrument.
Infra-red (IR) radiation: Electromagnetic radiation of wavelengths between approximately 750 nm and 1 mm. This is broken down into five wavelength regions:
Image swath: Maximum distance on ground between the positions of two spatial samples belonging to the same row.
Image sample: Image element containing radiance measurements of co-registered pixels for all bands.
Pixel: The FOV of a single detector element; the projection of that detector element onto the ground at a given instant.
Precision: The difference between one result and the mean of several results obtained by the same method, i.e. reproducibility (includes random errors only).
Visible light: Electromagnetic radiation detectable by the human eye with a wavelength between approximately 400 nm and 700 nm.
Scan: Defined as a complete rotation of the scan mirrors.
Scan cycle: Comprises two consecutive scans during which a complete set of targets are sampled.
Scan trace, or scan locus: The trace of a single detector element on the ground. For example, in the thermal channels each detector has two elements, and so a single scan gives two scan traces, displaced by 1 km in the along track direction at the swath centre in the nadir. Adjacent scan traces represent adjacent 'rows' of the instrument grid.
Target: Either the Earth view or one of the internal calibration targets (the VISCAL and the two black bodies); in the context of the telemetry data it refers to a section of the scan during which valid data is obtained, when the detectors are viewing the earth view or one of the calibration targets.