Physics of auroral phenomena : proceedings of the 33rd Annual seminar, Apatity, 02 - 05 March, 2010 / [ed.: A.G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2011. - 206 с. : ил.

The StellaCam II as an all-sky imager during the SCIFER 2 rocket campaign Table 1. The table shows over flying objects as seen from KHO in the interval 07:30-08:00 UT on 18 January, 2008. 1# Symbol Time period [UT] Quadrant ---------------------- j , —~~~ Object ID 1 □ 07:30:08-07:30:28 NW 2 f'.l 07:31:18-07:31:20 NW 3 □ 07:34:16-07:35:21 NW 4 □ 07:35:21 -07:35:40 NE 5 07:41:09-07:41:11 NE 6 □ 07:44:00-07:44:09 NW 7 □ 07:44:35-07:44:50 NE 8 □ 07:45:31 -07:45:31 SE 9 □ 07:46:55-07:47:04 SW 10 □ 07:49:03-07:50:47 SE - SW 11 □ 07:51:43-07:52:35 NW 12 □ 07:53:31 -07:54:14 NW - N E 13 0. 07:31:18-07:52:24 S - NE SCIFER 2 14 О 07:31:18-07:52:24 S - NE Position of SCIFER 2 mapped down the earth’s magnetic field line to 200 km of altitude. Note that the camera is not operating with single sequential exposed frames in real time (25 new frames per second). The video output of the camera shows the run time mean in real time o f the frames. This technique is developed for imaging of objects not moving fast like stars and planets, increasing the signal to noise. It actually works surprisingly well on aurora too, as long as the accumulation time is kept as short as possible compared to the movement of the aurora over the sky. In other words, the accumulated change of the aurora is observed in real time. This effect is not seen in the above animation, since each animated frame is the result of the total accumulated frames per second. The SCIFER 2 rocket payload flew over weak dayside aurora, located north of the camera zenith moving slowly northward during the flight. These arcs, named by Sandholt et al. [1989] Poleward Moving Auroral Forms (PMAFs), are produced by precipitating low energy electrons exciting atomic oxygen OI at wavelengths 6300 A (red) and 5577 A (green). The intensities of the arcs are just a few kR with a red to green ratio close to 5 [Deehr et al., 1980]. The peak altitude of the red emission is in the range 200 - 220 km [Sigernes et al., 1996]. The rocket as seen from KHO reached the horizon close to geographical South at 07:33:00 UT. The auroral activity was at this time stable, but fading slowly to almost disappear 4 minutes later. From this point in time the activity increased, and by the time the rocket past its highest altitude (1468 km), the activity was again high with arcs all over the sky. The magnetic field line mapping from the rocket down to the red emission peak altitude of 200 km may identify the low energetic electron precipitation region of the sky that is associated with ion outflow. There is no doubt that the rocket crossed several of these mapped regions with active arcs seen to the South - East of the animated trajectory. Communication with the rocket was lost at 07:52:26 UT with the payload falling down towards the horizon about 30 degrees off North towards East. 5. Concluding remarks The described StellaCam II camera with the Fujinon fisheye lens has proven itself to be a reliable and cost efficient alternative when intensified camera systems cannot be used on aurora. The cameras real time running mean video output works well for dayside auroral morphology studies. It helped us to be able to identify the target and locate the source areas of ion outflow. As a consequence, the SCIFER 2 rocket was launched successfully. References Baker, D. and G. Romick (1976), The Rayleigh: interpretation of the unit in terms of column emission rate or apparent radiance expressed in SI units, Applied Opt., 15(8): p. 1966-1968. Deehr, C. S., G. G. Sivjee, A. Egeland, K. Henriksen; P. E. Sandholt, R. Smith, P. Sweeney, C. Duncan, and J. Gilmer (1980), Ground-Based Observations of F Region Aurora Associated With the Magnetospheric Cusp, J. Geophys. Res., 85, 2185-2192. Hill, R. (1926), A Lens for Whole Sky Photography, Proceedings of the [3rd] Optical Convention [London 1926]. 2, 878-883. Kintner, P. М., J. Bonnell, R. Amoldy, K. Lynch, C. Pollock, T. Moore, J. Holtet, C. Deehr, H. Stenbaek-Nielsen, R. Smith, J. Olson, and J. Moen (1996), The SCIFER Experiment, Geophys. Res. Lett., 23, 14, 1865-1868. Mandea, М., and S. Macmillan (2000), International Geomagnetic Reference Field - the eighth generation, Earth Planets Space, 5 2 , 1119-1124. Sandholt, P.E., B. Lybekk, A. Egeland, R. Nakamura, and T. Oguti (1989), Midday auroral breakup, J. Geomagn. Geoelectr., 41, 371-378. Sigernes, F., J. Moen, D. A. Lorentzen, C. S. Deehr, R. Smith, M. 0ieroset, B. Lybekk, and J. Holtet (1996), SCIFER-Height measurements of the midmoming aurora, Geophys. Res. Lett., 2 3 , 14,1889 -1892. 45