Fig. S1	The Polar Cameras during laboratory calibration.  The fisheye lens, 
	filter wheel, and camera electronics unit of camera 1 can be seen,
	and the protective environmental enclosure is in place on camera 0.

Fig. S2	The Polar Cameras installed on the roof of the Arctic Stratospheric 
	Ozone Observatory, Eureka, NWT.  The moonshades wrapped around the
	cameras allow continuous observation through full moon periods.

Fig. S3	A sequence of Polar Camera images at 557.7 nm ([OI]), showing faint 
	polar arcs drifting dawnward over Eureka.  The images are 60-s time
	exposures at 5-6 min intervals, with north at the top and west to the 
	left.  The solar azimuth is toward the upper left corner.  The peak 
	arc brightness is about 500 R.  The altitude of these emissions is 
	at least 200 km, much higher than in the auroral oval.

Fig. S4	Simultaneous images of the drifting arcs at 630.0 nm ([OI]) with 2-3 
	min time resolution.  The peak brightness at this wavelength is 
	about 600 R.  Changes in arc brightness, spacing, and multiplicity
	can be clearly seen.

Fig. S5	A synthetic large-scale view of the convecting polar ionosphere.
	A succession of F region ionization patches is seen passing over the 
	geomagnetic pole near Eureka, faintly glowing (red - white) as atomic
	oxygens ions recombine.  This presentation shows the ionospheric 
	convection direction and speed, as well as the size, shape, orient-
	ation and spacing of the ionization patches which are produced in
	or near the magnetospheric cusp region on the dayside.