Dr. John B. Sigwarth

    Dr. John B. Sigwarth serves currently at Goddard Space Flight Center as 
the Project Scientist for the Polar spacecraft.  Most recently, his 
research has focused upon the conjugate nature of the northern and southern 
auroras; the impacts of geomagnetic storms on the atomic oxygen and 
molecular nitrogen composition of the thermosphere; the driving of the 
aurora by sharp increases in the dynamic pressure in the solar wind 
impacting the magnetosphere; the coupling efficiency of energy from the 
solar wind to the magnetosphere as a function of the state of the solar 
wind; the use of global auroral images to retrieve the energy deposition by 
auroral particles precipitating into the ionosphere; and the study of the 
rate of production of oxygen, hydroxide, and sodium from Comet 
Hale-Bopp.  Dr Sigwarth has authored or co-authored 136 presentations at 
scientific conferences and 73 papers for publication.
    Dr. Sigwarth has served as instrument scientist at The University of 
Iowa for the Visible Imaging System (VIS) that is one of the 11 instruments 
onboard the POLAR spacecraft managed by the NASA Goddard Space Flight 
Center (GSFC).  The VIS is a space flight qualified imager designed to 
acquire visible and ultraviolet images of Earth's aurorae, dayglow, ozone 
layer, and nightglow at the rate of approximately 1500 images per day.  Dr. 
Sigwarth was responsible for the analysis and implementation of the VIS 
designs to insure that project goals could be attained.  In particular, he 
designed the VIS Low Resolution Camera and the Medium Resolution Camera 
visible optics, the VIS Earth Camera ultraviolet optics, and the optical 
relays for the three sensors.  Also, he was directly responsible for the 
analysis, manufacture and testing of the optical systems of the VIS.  Dr. 
Sigwarth was responsible for final design, assembly and testing of the 
three VIS sensors.  Each sensor consists of an image intensifier coupled by 
an optical relay to a Charge Coupled Device (CCD).  In addition, he 
designed the VIS optical calibration setup, authored instrument test 
procedures, developed image analysis software, completed the calibration 
tests and performed analysis of the calibration data.  Dr. Sigwarth was 
responsible for verification, validation and space flight qualification of 
the VIS through the complete testing cycle prior to launch.  This testing 
included integration with the spacecraft as well as all major spacecraft 
level tests including vibration and thermal vacuum testing.
    As instrument scientist for the VIS, Dr. Sigwarth had a lead role in 
the scientific analyses of the images.  These analyses included the study 
of high-time and high-spatial resolution observations of the auroral oval 
and the relation of these observations to in-situ measurements of the solar 
wind and magnetosphere acquired with the international  array of spacecraft 
currently in operation.  Dr. Sigwarth was also the VIS team lead for 
Education and Public Outreach activities.
    Dr. Sigwarth received his Ph.D. from The University of Iowa in 
December, 1989.  In the fall semesters of 1997-1999 and 2003, he was part 
of a three person team to teach an introductory level course on Chemistry 
and Physics of the Environment to a class of greater than 300 college 
undergraduate students.  Dr. Sigwarth is a member of the American 
Geophysical Union.