Miscellaneous documentation

SuperDARN data visualisation software Go.

CUTLASS statistics stuff: stat-make, stat-int and IDL plotting routines.

Husafell all-sky camera images from 29 September 1998

In September 1998, a Japanese all-sky camera was deployed in Husafell, Iceland, to record the aurora. In collaboration with Natsuo Sato of NIPR, I am comparing these optical emissions with E region HF radar backscatter from the Pykkvibaer and Stokkseyri radars of the SuperDARN network (see the Leicester University, Radio and Space Plasma Physics Group home page for more information on the SuperDARN network). I've put quick-look summary files of the ASC images below (for general interest, though mainly because they're pretty). The images were originally recorded on VHS video in NTSC format (the Japanese and American broadcast standard), then converted to PAL (so I could view them on a British video player) and frame-captured using a Silicon Graphics O2 work-station (amazingly easily, too). Frame-grabbing the images and digitizing them allows the data to be quantified, manipulated, and projected into different coordinate systems, necessary for a proper comparison with other data sets.

To interpret the images, imagine lying on your back in a field in Iceland, with your head pointing north (magnetic north, to be exact), looking up at the sky. To your left is east, and to your right is west, with south at your feet. The images are taken with a 180 degree fish-eye lens, so the horizon describes a circle around the periphery of your vision; directly overhead is in the centre of your field of view. This is the format the images are plotted in. One image is shown every two minutes. Time is indicated at the bottom left of each image in the format hhmm UT. Little spots in the images are stars, and larger, darker, and more diffuse regions are the aurora. At first two bands of faint aurora are observed, one to the north, stretching from east to west, and one overhead stretching from NW to SE. Over time the northerly arc moves equatorwards and brightens, before breaking up into several arcs, filling the sky, and pulsating (not observable with this two minute time resolution).

Here are the images, 15 to a page (each page is approximately 500k in size so may take some time to load):

0302-0330 UT, 0332-0400 UT, 0402-0430 UT, 0432-0500 UT.

As the work progresses I might add some radar data here...

Myopic campaign intervals

SuperDARN radars are designed to scatter from F region irregularities, which are known to drift with the background bulk plasma flow and hence act as a diagnostic for the convection electric field. Backscatter is also observed from E region irregularities, which do not drift at the ExB velocity, but this is usually considered contamination of the data-set. However, study of the spectral characteristics of E region backscatter allows investigation of fundamental plasma dynamics, including instability mechanisms such as the two-stream (Farley-Buneman) and gradient drift instabilities. I designed the "Myopic" scan mode to maximise observation of E region backscatter by viewing only the near-range field-of-view at high spatial resolution (i.e. range to first gate 180 km, gate length 15 km).

View Myopic schedule.

The Myopic mode is run on a campaign basis. The most often employed radar for Myopic observations is Iceland East, though recently, simultaneous runs on Iceland East and West have proved very successful. Also, recent campaigns have been conducted in collaboration wih Japanese optical observations from Husafell, Iceland (see above).

View an example of Myopic observations from the two Icelandic radars from 15 Feb 1999, 2200 UT - 16 Feb 1999, 0200 UT. The E region backscatter appears as east-west aligned features at near ranges.

I'll add a list of other interesting intervals here at some point. For now:

15 Feb 1999, 2200 UT - 16 Feb 1999, 0200 UT - Optical comparison with Husafell all-sky camera.

Polar UVI and CUTLASS paper figures

"Dayside convection and auroral morphology during an interval of northward interplanetary magnetic field"
S. E. Milan, M. Lester, S. W. H. Cowley, and M. Brittnacher
Ann. Geophysicae, in preparation, 1999.

Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6.

Coordinate systems and transformations

Locations of CUTLASS fields-of-view and additional information: Finland and Iceland.

Conversion between geographic and Corrected Geomagnetic Coordinates (CGM).

Algorithms for conversion between several Space Physics coordinate systems.

"What's the good of Mercator's North Poles and Equators,
     Tropics, Zones, and Meridian Lines?"
So the Bellman would cry: and the crew would reply
     "They are merely conventional signs!"

- The Hunting of the Snark, Lewis Carroll.

Publication list

Essential reading material: view my publication list.

Um, that's it...

Well, a bit empty this at the moment. Clearly I haven't been doing enough work recently...

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