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Leonid MAC

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flag Joseph Kristl,
Stewart Radiance Laboratory

Last updated: October 2001
E-Mail: jkristl [at]

Brief Biographical Information:

After completing a BS in physics at the Massachusetts Institute of Technology in 1982, Mr Kristl went to work for the USAF and started flying on the FISTA aircraft, planning missions and operating infrared sensors. After separating from the Air Force as a Captain in 1986, he moved over to Stewart Radiance Laboratory, part of the Space Dynamics Laboratory of Utah State University. Since then he has continued to fly on the FISTA aircraft and has participated in many measurement programs (~1300 flight hours). He currently heads the "FISTA group" in the Space Dynamics Laboratory, who develops new instrumentation for aircraft platforms, as well as conducting measurements and performing analysis of the resulting data. Mr. Kristl is the author of numerous technical reports detailing the infrared signatures of aircraft and rockets for the DoD. He develops flight plans, flies on the missions, and analyzes and presents the final data. He has also developed much of the data collection and analysis software currently in use with the FISTA sensor systems.


The FISTA group in the Space Dynamics Laboratory (SDL) is located in the Stewart Radiance Laboratory (SRL) facility in Bedford, MA. Numerous infrared and visible calibrated sensors have been developed there for the FISTA aircraft and other aircraft platforms. The primary business of the FISTA program is the conduct of airborne measurements of targets and backgrounds of interest to the US DoD. SDL has a contract with the Air Force Research Laboratory, Backgrounds Characterization Branch (AFRL/VSBC) to develop, operate, and fly sensors in the FISTA program. SRL has built Michelson interferometers suitable for an aircraft platform, as well as high speed radiometers and calibrated infrared imaging systems. It is currently developing advanced sensors such as imaging infrared interferometers and high speed radiometric systems.

The parent organization, Space Dynamics Laboratory, has built and flown many infrared sensors for rocket and satellite platforms, including the Space Shuttle and other long-term orbiting systems.

Research on Leonid MAC:

near-IR (1.0-3.1 micron) spectroscopy of meteors and trains.The AFRL/SRL team is also assisting many of the other FISTA aircraft users in the interface and installation of their equipment on the aircraft.

During the 1999 Leonid multi-aircraft campaign, Mr Kristl worked with the AFRL and SRL research teams to operate three instruments: 2 Michelson interferometers and one infrared imager. The two interferometers cover the 1 - 3 micrometer band of the spectrum. These instruments will be tracked onto the persistent meteor trains to try and spectrally measure the emission in this band, which should help identify the radiating species and give insight into exactly what is happening in a persistent train. Each interferometer has a co-aligned low light level sensor so that the small field of view of the interferometer can be directed onto the persistent train.

Results included the detection of an increase of OH emission at the peak of the meteor storm (more info here), and the first detection of meteors in the near-IR (unpublished data).

During the 2001 Leonid MAC mission, a Bomem spectrograph will be deployed in an effort to confirm the increase of OH coincident with the meteor storm. In addition, three mid-IR imagers will be deployed from FISTA with bandpass filters chosen to pick up the 3.4 um band, in tsearch for organic matter release. Our equipment continues to improve (our continuous digital recording software is much better than during Leonid 99). One innovation we have been developing (for reasons utterly unrelated to meteors) is the capability to record our IR imagery at extremely high data rates, providing potentially a VERY detailed time history of its spatial structure if a bright enough meteor passes its field of view.

Bomem Interferometer
Bomem Interferometer 102 installed on FISTA

group photo
1998 Leonid AFRL/SDL Measurement Team: Sandra Nierman, Thomas Hudson, and Joseph Kristl

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