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DMSP: The DMSP particle
precipitation data provides the "core" of OVATION by serving as the
cross-calibration standard. The Defense Meteorological Satellite Program
consists of a series of low-altitude (840 km), polar-orbiting (98.7o
inclination), sun-synchronous satellites in circular orbits. The SSJ/4
electrostatic analyzer built by D. Hardy, F. Rich, and colleagues at the Air
Force Research Laboratory measures electrons and ions from 32 eV to 30 keV,
which covers most particles associated with the aurora. DMSP data at JHU/APL
is provided by both F. Rich of AFRL, and by the NOAA World Data Center A in
Boulder, Colorado. NOAA data reaches JHU/APL one or more years late, but does
partially fill some data gaps. Auroral oval boundaries are identified by
procedures developed at JHU/APL.
DMSP data included in OVATION begins in December 1983,
with data from DMSP F6 and F7 ("F" = flight number). Data gaps are
comparatively rare in the DMSP data set, but the temporal resolution is poor
(about 50 minutes per updated position).
UVI: The NASA satellite
Polar takes global pictures of the aurora in ultraviolet (which allows daytime
auroral images). The imager, called UVI, was designed by M. and D. Torr.
G. Parks of the University of California, Berkeley is the Principal
Investigator on UVI, while C. Meng of JHU/APL is co-investigator. The
boundary identifications used here were developed and cross-calibrated to DMSP
by J. Carbary (JHU/APL). Polar UVI data is available from April 1996 through
the present. Auroral images are available only for the northern hemisphere.
Large data gaps occur daily, whenever Polar is not in position to observe the
northern hemisphere polar regions. The time resolution of Polar UVI (in the
LBH-L filter used for this work) is typically one image every 1 min 30 s, but
can vary.
University of Alaska, Fairbanks MSP (Meridian Scanning Photometer): The UAF MSP scans the skies from north-to-south to record auroral emissions. Auroral boundary location software was developed by C. Deehr and D. Wilkinson of UAF, who also cross-calibrated these boundaries with DMSP. The MSP data is high time resolution, but only works (1) in darkness, (2) under fair skies, (3) when the auroral oval is within a few degrees of Fairbanks (which it fortunately often is).
SuperDARN: The Super
Dual Auroral Radar Network is an international
collaborative program for scientific investigation of the upper atmosphere,
ionosphere and magnetosphere. SuperDARN consist of a collection of HF radars
located in the Northern and Southern hemispheres. (Presently, we are using
only the norther radars for real-time, not historical, data.) The data are being supplied courtesy of R. A.
Greenwald and J.M. Rhuohoniemi of JHU/APL.