• SSTV Goes Very High Profile

    From ARRL de WD1CKS@VERT/WLARB to QST on Thu Oct 26 14:22:40 2017
    10/26/2017

    In late September, University of Alaska-Fairbanks researcher Chris Fallen, KL3WX, was attempting to produce an RF-induced airglow - or artificial aurora - using the High Frequency Active Auroral Research Program (HAARP[1]) facility near Gakona, Alaska, to warm up the atmosphere. Clouds hampered his experiment, but Fallen alerted his Twitter followers that he also had embedded a few Slow-Scan Television (SSTV) frames in the powerful HAARP signal, which were copied in British Columbia and in Colorado.

    "The SSTV images, aside from being a fun way to engage hams in some of the ionosphere-heating science performed at HAARP, will be useful for understanding radio propagation from Arctic or high-latitude sources," Fallen told ARRL.

    HAARP consists of multiple transmitters feeding 180 phased-arrays and is capable of producing 3.6 MW (that's megawatts) of RF. HAARP's signal is essentially aimed straight up.

    The assistant professor at the UAF's Geophysical Institute transmitted two UAF logos, a photo of his cat - appearing as a giant feline next to the HAARP antenna field, and - most unusual - a QR code granting the recipient 0.001 Bitcoin. The SSTV images were not the best, and you almost need to use your imagination to make out the cat.

    The first SSTV reception report arrived from Walt Salmaniw in Victoria, British Columbia, using a Perseus SDR, MixW software, and a north-directed corner fed loop. The second SSTV report arrived from Michael Coletta, KM0MMM, Pueblo, Colorado.

    His transmissions were on three discrete frequencies in the 2.8 MHz range. Fallen used different frequencies and antenna phase settings to determine if those factors would affect the airglow.

    "I used Scottie-1 encoding for the images, because it is widely used in North America and the ~120-second duration fit nicely into the airglow experiment," Fallen said. "The antenna was directed toward the HAARP magnetic zenith, which, at ~75° elevation, is nearly vertical but has often been found by previous scientists to maximize artificial airglow. One factor affecting both the airglow experiment and the reception is that local foF2 had dropped below the transmission frequency of approximately 2.8 MHz at the time of the experiment." He believes the British Columbia and Colorado reports came from the side lobes of HAARP's primary beam.

    Fallen told ARRL he still has some HAARP time left from his September campaign, although he's not certain what he'll use it for. His next opportunity to experiment further won't be until early next spring. HAARP conducts just two experimental campaigns a year, due to staff and funding constraints.


    [1] http://www.gi.alaska.edu/haarp

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