It's a bird! No, it's a plane! No, it's Freja!


Watch Freja in orbit, as seen by the Portable Auroral Imager from Rabbit Lake, SK, as she falls (with style) eastward through the constellations of Lynx and UMa. The clip below shows the March 5 1995 0410 UT encounter with a temporal resolution of approximately 1 second. A 105 mm lens was used. A 3 s flash period with a 6 s period modulation is obvious in the original footage (not obvious in this rather crude MPEG), consistent with Freja's 6 s spin period. Note the westward drifting evening diffuse aurora in the foreground (north is up, west is to the right).

Get some popcorn, put the theme from `2001' on the CD player, and click here to see Freja:

Finding Freja in the P.A.I. footage was done as part of the process of verifying the accuracy of the coordinate grids established for P.A.I. Using stars, azimuth/elevation grid-lines had been determined using the excellent xephem, and these were in turn used to determine geographic and geomagnetic lat/lon grid-lines at a given altitude. These grids were then tested against the SatTrack satellite tracking program which was used to predict the location of Freja within the field of view at the given time.

If you're interested in observing satellites, have a look at the Visual Satellite Observer's Home Page.


The Portable Auroral Imager Home Page



Last modified March 22, 1996 by Trond S. Trondsen (trondsen@phys.ucalgary.ca)