BackForwardInstrument:  ISUAL 

Instrument details
Acronym ISUAL
Full name Imager of Sprites and Upper Atmospheric Lightning
Purpose To observe TLEs (Transient Luminous Events: the natural upward lightning discharge phenomena toward the ionosphere on top of the troposphere)
Short description CCD camera composed of an intensified sprite imager, a six-channel spectrophotometer and a two-channel array photometer. Time resolution: 180 frames/s. The fotometers operate in the bands 360-450 nm and 525-880 nm, respectively
Background New development
Scanning Technique Fixed nadir pointing, 512x80 detectors, field of view 20º x 3.15º (320 km cross-track, 50 km along-track)
Resolution 650 m at s.s.p.
Coverage / Cycle Global in one week (only in night time)
Mass Power Data Rate


Providing Agency NSPO
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2004 to 2016
Last update: 2022-07-27
Detailed characteristics
Satellites this instrument is flying on

Note: a red tag indicates satellites no longer operational, a green tag indicates operational satellites, a blue tag indicates future satellites

Instrument classification
  • Earth observation instrument
  • Passive optical radiometer or spectrometer
  • Lightning imager
WIGOS Subcomponents No WIGOS subcomponents have been defined.
Mission objectives
Primary mission objectives
  • Total lightning density
Evaluation of Measurements

The following list indicates which measurements can typically be retrieved from this category of instrument. To see a full Gap Analysis by Variable, click on the respective variable.

Note: table can be sorted by clicking on the column headers
Note: * Primary mission objective.
VariableRelevance for measuring this variableOperational limitationsExplanation
Total lightning density*5 - marginalDiscontinuous availability.. Night time only.Coincidence flashes in UV/VIS/NIR channels, exploited for Transient Luminous Events (TLE) in the upper atmosphere.