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OTD Global Lightning Mapper

NSSDCA ID: 1995-017C-01

Mission Name: Microlab 1
Principal Investigator:Dr. Hugh J. Christian, Jr.


The Optical Transient Detector (OTD) is the world's first space-based sensor capable of detecting, locating and measuring the intensity of lightning events in the daytime as well as during the nighttime. A similar instrument, the Lightning Imaging Sensor (LIS), is being developed for the NASA Earth Observing System (EOS). The sensor can detect the lightning flashes from cloud to ground, cloud to cloud, and intra-cloud (within cloud) lightning events. Ground-based techniques detect only cloud-to-ground lightning events which are believed to comprise 25% of the total lightning activity. The OTD measurements contribute to studies of Earth's water cycle, sea-surface temperature variations, electrical coupling of thunderstorms with the ionosphere and magnetosphere, and modeling of the global distribution of electrical fields and currents in the Earth's atmosphere. The OTD development team adopted a fast-track, low-cost approach, making maximum use of engineering model hardware configured for flight on a small satellite. Launch on the Orbital Sciences Corporation Pegasus rocket was provided free via a data buy arrangement providing low cost access to space with a shared government-industry risk factor. The instrument was designed, fabricated, space qualified, calibrated, and delivered within a period of nine months. It is designed to observe lightning for a period of two years or more. References and results can be found at the LIS/OTD home page at

Alternate Names

  • Microlab1/OTDGlobalLightningMapper
  • Optical Transient Detector (OTD)


  • Earth Science: None assigned

Additional Information

Questions and comments about this experiment can be directed to: Dr. Dieter K. Bilitza



NameRoleOriginal AffiliationE-mail
Dr. Steven J. GoodmanGeneral ContactNASA Marshall Space Flight
Dr. Hugh J. Christian, Jr.Principal InvestigatorNASA Marshall Space Flight
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