# Analysis of Radar and Air-Visual UFO Observations on 24 October 1968 at Minot AFB, North Dakota, USA

Claude Poher, Ph.D.

## Appendix 2

### Descriptive Measurements of Radarscope Photos 771 to 784

Note: The distance should not be calculated from the center of the photo, since there is an “offset” of calibration in distance and the first zone is not linear. Distances should be measured by using the circle (range ring) that is visible in all photos at 1.75 nm.

##### Analysis of Photo 771
Heading of the B-52 = 122°
Heading at the top of the photo = 118.2°
Distance to the edge of the altitude hole = 2.2 nm
I determined the presence of two echoes on this photo on the right side of the aircraft and forward at positions 13 h and 14 h. The smallest seems to be an artifact of the ground.
Small echo: Distance = 2.15 nm Direction = 152°
Large echo: Distance = 1.73 nm Direction = 138°
Orientation of the longer axis of the largest echo = 110 / 290°
Positions on photo:
• Small echo: x = 1071 y = 906 (pixels)
• Large echo: x = 988 y = 935 (pixels)
Position of the B-52:
• x = 921 y = 1130 (pixels)
Photometric levels:
• Small echo: 70 %; level of neighborhood = 30 %
• Large echo: 67 %; level of neighborhood = 25 %
• Echo of ground near the edge of the altitude hole = 91%
• NB: Black = 100 % — White = 0 %
Dimension of echoes:
• Large echo: length = 11 pixels; width = 3 pixels (132 x 40 meters).
• Small echo: circle, 2 pixels diameter (28m)
Scale of the photo = 140 pixels per nautical mile (linear, center displaced by 0.25 nm)
The resolution of the radar seems to be 2 pixels.

##### Analysis of Photo 772
Heading of the B-52 = 124°
Heading of the top of the photo = 117.2°
Distance to the edge of the altitude hole = 2.13 nm
I determined the presence of only one echo on this photo, which is about the same size as the largest one in the previous photo. The echo has moved towards the right rear of the aircraft to a position at 16 h.
Distance = 1.12 nm Direction = 244°
Orientation of the larger axis of the echo = 100 / 280°
Position on photo: x = 970 y = 1194 (pixels)
Position of the B-52: x = 878 y = 1131 (pixels)
Photometric levels:
• Echo: 58 %; level of neighborhood = 19 %
• Echo of ground near the edge of the altitude hole = 91 %
• NB: Black = 100 % — White = 0 %
Dimension of echo: length = 9.4 pixels; width = 4 pixels (120 x 50 meters).
Scale of the photo = 146 pixels per nautical mile (linear, center displaced by 0.25 nm).

##### Analysis of Photo 773
Heading of the B-52 = 122°.
Heading of the top of the photo = 117.5°
Distance to the edge of the altitude hole = 2.13 nm
I determined the presence of only one echo, which is considerably larger in size than the one in the previous photo. The echo has moved towards the left of the aircraft at a position of 21 h.
Distance = 1.05 nm Direction = 039°
Orientation of the larger axis of the echo = 050 / 230°
Position on photo: x = 783 y = 1061 (pixels)
Position of the B-52: x = 891 y = 1084 (pixels)
Photometric levels:
• Echo: 81 %; level of neighborhood = 23 %
• Echo of ground near the edge of the altitude hole = 91 %
• NB: Black = 100 % — White = 0 %
Dimension of echo: length = 21.2 pixels; width = 9.2 pixels (260 x 113 meters + 185 m with a sort of appendage).
Scale of the photo = 150 pixels per nautical mile (linear, center displaced by 0.25 nm).

##### Analysis of Photo 774
Heading of the B-52 = unknown
Heading of the top of the photo = 117.7°
Distance to the edge of the altitude hole = 2.06 nm
No apparent echo on this photo. There is a sort of artifact at 0.73 nm / 025°, however this artifact exists on all photos. Its contrast is quite low: 44% neighborhood = 31 %
Positions of artifact on photo: x = 938 y = 1143 (pixels)
Position of the B-52: x = 1003 y = 1140 (pixels)
Scale of the photo = 148 pixels per nautical mile (linear, center displaced by 0.25 nm).
Photometric levels:
• Echo: 41 %; level of neighborhood = 31 %
• Echo of ground near the edge of the altitude hole = 88 %
• NB: Black = 100 % — White = 0 %
The dimension of artifact is too noisy for a correct measurement.

##### Analysis of Photo 775
Heading of the B-52 = unknown
Heading of the top of the photo = 117.7°
Distance to the edge of the altitude hole = 2.04 nm
I determined the presence of only one echo on this photo with a size comparable to the one in photo 773. The echo has moved towards the rear of the aircraft to a position at 19.5 h.
Distance = 1.69 nm Direction = 348°
Orientation of the larger axis of the echo = 106 / 286°
Position on photo: x = 842 y = 1200 (pixels)
Position of the B-52: x = 1005 y = 1069 (pixels)
Photometric levels:
• Echo: 94 %; level of neighborhood = 65 %
• Echo of ground near the edge of the altitude hole = 89 %
• NB: Black = 100 % — White = 0 %
Dimension of echo: length = 19.2 pixels; width = 7 pixels (247 x 90 meters).
Scale of the photo = 144 pixels per nautical mile (linear, center displaced by 0.25 nm).

##### Analysis of Photo 776
Heading of the B-52 = unknown
Heading of the top of the photo = 117.9°
Distance to the edge of the altitude hole = 2.04 nm
I determined the presence of three echoes on this photo. One of these echoes has a size comparable to the one in photo 773. This echo has moved towards the front of the aircraft to a position at 21 h.
Echo 1: Distance = 1.08 nm Direction = 040°
Echo 2: Distance = 1.55 nm Direction = 245°
Echo 3: Distance = 1.55 nm Direction = 253°
Orientation of the larger axis of the echo 1 = 040 / 220°
Orientation of the larger axis of the echo 2 = 122 / 302°
Orientation of the larger axis of the echo 3 = 124 / 304°
Positions on photo:
• Echo 1: x = 894 y = 1144 (pixels)
• Echo 2: x = 1148 y = 1266 (pixels)
• Echo 3: x = 1133 y = 1288 (pixels)
• Position of the B-52: x = 1006 y = 1166 (pixels)
Photometric levels:
• Echo 1: 56 %; level of neighborhood = 30 %
• Echo 2: 66 %; level of neighborhood = 33 %
• Echo 3: 61 %; level of neighborhood = 36 %
• Echo of ground near the edge of the altitude hole = 90 %
• NB: Black = 100 % — White = 0 %
Dimension of the echoes:
• Echo 1: length = 26,6 pixels; width = 6 pixels (337 x 76 meters).
• Echo 2: length = 18 pixels; width = 5 pixels (102 x 63 meters).
• Echo 3: not measurable (noise).
Scale of the photo = 146 pixels per nautical mile (linear, center displaced by 0.25 nm).

##### Analysis of Photo 777
Heading of the B-52 = unknown.
Heading of the top of the photo = 117.3°
Distance to the edge of the altitude hole = 1.98 nm
I determined the presence of three echoes on this photo. The upper echo could be an artifact.
Echo 1: middle
Echo 2: lower
Echo 3: upper (artifact?)
Echo 1: Distance = 1,05 nm Direction = 040°
Echo 2: Distance = 1,75 nm Direction = 246°
Echo 3: Distance = 1,58 nm Direction = 094°
Orientation of the larger axis of the echo 1 = 065 / 245°
Orientation of the larger axis of the echo 2 = 060 / 240°
Echo 3 is circular
Positions on photo:
• Echo 1: x = 912 y = 1041 (pixels)
• Echo 2: x = 1179 y = 1181 (pixels)
• Echo 3: x = 942 y = 891 (pixels)
Position of the B-52: x = 1018 y = 1062 (pixels) Photometric levels:
• Echo 1: 47 %; level of neighborhood = 25 %
• Echo 2: 73 %; level of neighborhood = 46 %
• Echo 3: 79 %; level of neighborhood = 3 % (white dot behind)
• Echo of ground near the edge of the altitude hole = 84 %
• NB: Black = 100 % — White = 0 %
Dimension of the echoes:
• Echo 1: length = 10 pixels; width = 3 pixels (120 x 36 meters).
• Echo 2: length = 17.8 pixels; width = 7.2 pixels (214 x 87 meters).
• Echo 3: diameter 4 pixels (48 meters).
Scale of the photo= 154 pixels per nautical mile (linear, center displaced by 0.25 nm).

##### Analysis of Photo 778
Heading of the B-52 = unknown
Heading of the top of the photo = 117.7°
Distance to the edge of the altitude hole = 1.97 nm
I determined the presence of only one echo on this photo. The preceding middle echo has not moved at the position of 21 h.
Distance = 1.05 nm Direction = 040°
Orientation of the larger axis of the echo = 082 / 262°
Position on photo: x = 891 y = 1053 (pixels)
Position of the B-52: x = 8975 y = 1076 (pixels)
Photometric levels:
• Echo: 61 %; level of neighborhood = 20 %
• Echo of ground near the edge of the altitude hole = 78 %
• NB: Black = 100 % — White = 0 %
Dimension of echo: length = 8 pixels; width = 5 pixels (100 x 63 meters).
Scale of the photo = 148 pixels per nautical mile (linear, center displaced by 0.25 nm).

##### Analysis of Photo 779
Heading of the B-52 = unknown.
Heading of the top of the photo = 117.0°
Distance to the edge of the altitude hole = 1.95 nm
I determined the presence of only one echo in this photo. There is also a sort of long filament with a low contrast, at 1.25 nm distance. The preceding echo has not moved from the previous position at 21 h.
Distance = 1.0 nm Direction = 040°
Orientation of the larger axis of the echo = 040 / 220°
Position on photo: x = 914 y = 998 (pixels)
Extremity of the filament: x = 894 y = 994 (pixels)
Position of the B-52: x = 1009 y = 1020 (pixels)
Photometric levels:
• Echo: 51 %; level of neighborhood = 22 %
• Echo of ground near the edge of the altitude hole = 80 %
• NB: Black = 100 % — White = 0 %
Dimension of echo: length = 7 pixels; width = 6 pixels (86 x 74 meters). Length of the filament = 25 pixels (300 meters).
Scale of the photo = 150 pixels per nautical mile (linear, center displaced by 0.25 nm).

##### Analysis of Photo 780
Heading of the B-52 = unknown.
Heading of the top of the photo = 116.4°
Distance to the edge of the altitude hole = 1.90 nm
I determined only one echo on this photo at the same position as previous at 21 h.
Distance = 1.05 nm Direction = 040°
Orientation of the larger axis of the echo = 065 / 245°
Position on photo: x = 918 y = 1169 (pixels)
Position of the B-52: x = 1018 y = 1192 (pixels)
Photometric levels:
• Echo: 66 %; level of neighborhood = 20 %
• Echo of ground near the edge of the altitude hole = 80 %
• NB: Black = 100 % — White = 0 %
Dimension of echo: length = 12 pixels; width = 4 pixels (150 x 50 meters).
Scale of the photo = 144 pixels per nautical mile (linear, center displaced by 0.25 nm).

##### Analysis of Photo 781
Heading of the B-52 = unknown.
Heading of the top of the photo = 118.5°
Distance to the edge of the altitude hole = 1.87 nm
I determined the presence of only one echo on this photo. The echo has not moved from the position at 21 h.
Distance = 0.95 nm Direction = 040°
Orientation of the larger axis of the echo = 102 / 282°
Positions on photo: x = 842 y = 1150 (pixels)
Position of the B-52: x = 934 y = 1168 (pixels)
Photometric levels:
• Echo: 52 %; level of neighborhood = 21 %
• Echo of ground near the edge of the altitude hole = 90 %
• NB: Black = 100 % — White = 0 %
Dimension of echo: length = 8 pixels; width = 3 pixels (95 x 35 meters).
Scale of the photo = 156 pixels per nautical mile (linear, center displaced by 0.25 nm).

##### Analysis of Photo 782
Heading of the B-52 = unknown.
Heading of the top of the photo = 118.7°
Distance to the edge of the altitude hole = 1.83 nm
I determined the presence of only one echo on this photo. The echo has moved slightly at the position at 21 h.
Distance = 0.91 nm Direction = 038°
Orientation of the larger axis of the echo = round, fuzzy
Position on photo: x = 912 y = 1123 (pixels)
Position of the B-52: x = 986 y = 1136 (pixels)
Photometric levels:
• Echo: 52 %; level of neighborhood = 20 %
• Echo of ground near the edge of the altitude hole = 90 %
• NB: Black = 100 % — White = 0 %
Dimension of echo: length = 4 pixels; width = 3 pixels, fuzzy (48 x 36 meters).
Scale of the photo = 154 pixels per nautical mile (linear, center displaced by 0.25 nm).

##### Analysis of Photo 783
Heading of the B-52 = unknown.
Heading of the top of the photo = 118.7°
Distance to the edge of the altitude hole = 1.82 nm
No echo on this photo.
Position of the B-52: x = 1001 y = 1210 (pixels)
Photometric levels:
• Echo of ground near the edge of the altitude hole = 76 %
• NB: Black = 100 % — White = 0 %
Scale of the photo = 150 pixels per nautical mile (linear, center displaced by 0.25 nm).

##### Analysis of Photo 784
Heading of the B-52 = unknown.
Heading of the top of the photo = 119.0°
Distance to the edge of the altitude hole = 1.79 nm
No echo on this photo, however, there is a “negative” blip to the rear of the B-52.
Distance of blip = 2.99 nm Direction = 312°
Orientation of the larger axis of the blip = 040 / 220°
Position of the blip on photo: x = 1437 y = 1819 (pixels)
Position of the B-52: x = 1516 y = 1434 (pixels)
Photometric levels:
• Negative Blip: 33 %; level of neighborhood = 79 %
• Echo of ground near the edge of the altitude hole = 100 %
• NB: Black = 100 % — White = 0 %
Dimension of negative blip: length = 7 pixels; width = 3 pixels, fuzzy (80 x 35 meters?).
Scale of the photo = 150 (?) pixels per nautical mile.

Appendix 3 ››