DECEMBER
Year Surface 1,500M 3,000M 5,000M 10,000M
El Paso 1944 N-3 NNE-1 W-2 NW-1
1945 NNE-3 W-3 WNW-6 WNW-6
Roswell 1944 S-1 NW-3 NW-4 WNW-6
1945 SSE-3 WSW-2 WNW-5 WNW-8
Albuquerque 1944 N-3 -- WNW-4 WNW-6 W-10
1945 N-3 -- NW-6 WNW-8 WNW-9
Amarillo 1944 NW-4 NW-4 WNW-5 WNW-6 WNW-8
1945 SW-3 W-2 WNW-5 WNW-9
Big Spring 1944 -- NW-4 NW-5 WNW-6
1945 -- WSW-3 W-6 WNW-7
D. Tracking Devices: Horizontal
The flights made in the early part of this program were tracked optically with theodolites. Coupled with the height data, theodolite readings provide a fairly reliable horizontal locus of the balloon. However, even in the clear air of New Mexico, this method is useful for not more than 100 miles and, unless accurate height data are available, theodolite stations provide useful data for not more than 40 miles.
Aircraft observations have been used with some success when the ceiling of the balloon is not too great. It is expected that an inverted AN/APQ-13 radar, mounted atop a B-17, will greatly augment the horizontal tracking and will be of some value in determining height.
The most useful equipment for determining horizontal movement of the balloons has been the SCR-658 radio direction finding set. Long after the vertical angles registered by this gear are questionable (due to reflections off intervening terrain), the horizontal angles are useable. Used in sets of two or more, or coupled with height data, these observations give good positions with distances up to 150 miles. Figure 18 shows the coverage a network of four of these sets would provide. In contrast to the theodolites and aircraft observations, these instruments are perfectly operative when