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This report details the coordination between SuperDARN radar network and spacecraft, focusing on THEMIS, Cluster, Double Star, and Geotail missions. Regular scans and conjunction analyses are performed to study magnetopause and magnetotail phenomena.
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Spacecraft working group reportSuperDARN workshop 2011 Rob Fear, Jim Wild & the spacecraft working group
SuperDARN coordination with spacecraft • Every month Jim downloads Cluster and THEMIS predicted orbit files and generates orbit and footprint plots • Available at http://spears.lancs.ac.uk/~wildj/themis/ • Spacecraft working group examines plots manually for favourable conjunctions between SuperDARN network and Cluster (2001-), Double Star (2004-2007), THEMIS (2007-) & Geotail • We request 150-250 hours per month for a special “themisscan” mode • One beam sounding at 3s cadence allows high-resolution timing for THEMIS studies • Interlaced within normal two-minute scan of full FOV
Early phase of THEMIS mission (2008/9) • In 2008/9 we tended to target: • THEMIS ‘prime conjunctions’ • Out-of-phase alignments along the magnetopause • Cluster/THEMIS simultaneous observations of the flanks THEMIS Cluster
ARTEMIS-1 THEMIS Cluster ARTEMIS-2 June 2010 to present • ARTEMIS is now in lunar orbit, so there are no longer any ‘prime conjunctions’ • ARTEMIS tail pass now a regular monthly target • Spends ~5 days per month in magnetotail • We target the magnetopause crossings and ‘Fast mode’ in tail (00 to 06 UT) 20-27 October 2010 20-27 October 2010
Other current targets 22 October 2010 • The inner three THEMIS spacecraft are (almost) in the same daily orbit • This allows us to be a bit more fussy, and require (for example) a spacecraft at the magnetopause AND a spacecraft in the magnetotail • We also now factor Geotail’s orbit in more regularly
Cluster and the Auroral Acceleration Region • In the coming months, Cluster is due to cross the auroral acceleration region during its perigee passes • Crossings will occur mainly at dusk local times • Cluster PI teams are in process of selecting best perigee passes for burst mode operations • ‘Best’ passes are being selected in part on conjunction with SuperDARN and other ground-based instrumentation • Cluster tail crossings are not expected to provide much useful data (partly due to orbit evolution, partly due to eclipses) so the AAR will be the main science target for Cluster (and hence our requested conjunctions) in the next few months
Summary • SuperDARN is run in ‘themisscan’ mode for about 200 hours a month • Change of THEMIS orbits means ‘prime conjunctions’ are no longer available • We mainly target ARTEMIS fast mode intervals whilst in the magnetotail • 24 hour period of inner THEMIS spacecraft allows us to require spacecraft in two regions of interest for remaining conjunctions • Auroral acceleration region is likely to be main target for next few months • If you have any thoughts or requests for what we should be targeting, please get in touch!