March 1966 observations of the galactic spur in the 20 to 40 MHz range

In March 1966 observations were made at the Arecibo Ionospheric Observatory to map the region of the Galactic Spur (North Polar Spur) in the 20-40 MHz range. Simultaneous observations were made at 38.75, 33.45, 26.70, and 22.30 MHz using a log-periodic feed, a four-way power divider, and individual null-balancing radiometers. Antenna half-power beamwidths were roughly 2.0 degrees at 38.75 and 3.3 degrees at 22.30 MHz. The observations were confined to the 2300-0500 local time period to minimize ionospheric effects. The area observed was between 12h and 16h right ascension, +32 degrees and +2 degrees declination. Results are given in the report.