Scientific Study of Unidentified Flying Objects (the Condon Report, complete, three volumes)

B. Blip-lik.f'...:... Cases where the radar target (or ta;·.~ets)
showed characteristics similar to the return from a solid ob-
ject (such as an aircraft, etc.), and where the target did Tlot
display erratic or discontinuous behavior. Acceleration or
velocity in excess of known aircraft capabHities, or periods of
immobility, were not considered to be contrary to normal targeL
behaV'ior.
In the following section cases of particular interest are treated
in detail; thes0 cases generally fall into one of three categories:
(a) Cases that are good examples of inconsistencies tend1ng to
confuse any conclusions that might be arrived at;
(b) Cases that are typical of a sub-group of UFO reports that
have the same probahle explanation;
(c) Cases that are difficult or seemingly impossible to explain
in terms of known rhenomena.
2. Presentation of Radio Refractive Index Data
Two methods of presenting vertical profiles of radio Ycfractivjty
in graphical form are used in this chapter. Roth methods are based
on the use of the radio refractivity, N, ~here
6
N ~ (n - 1) x 10 ,
since the radio refractive index, n, is always very close to unity
in the atmosphere. The maximum value of N that is likely to he
encountered jn the atmosphere is not much over 400; values close to
500 may occasionally be experienced over the surface of the Dead Sea,
1200 ft. below s('!a level, in rhe summer months.
A f~ature of all vertical profties of N is a general decrease
with height; the departures of any given profile from the average
decrease with height are the significant features for anomalous
propagation of radio waves. '111erefore the refracti ve iTldex profi 1es
illustrated for many of the UFO cases ill th€' following secti"n are
given in term3 of A-units (Bean, 1966a) where
176
B. Blip-U k_~'..:... Cases where the radar target (or ta;'~ets)
showed characteristics similar to the rchlrn from a solid oh-
ject (such as an aircraft, etc.), and where the target did not
display erratic or discontinuous hehavior. Acceleration or
velocity in excess of known aircraft capabilities, or periods of
immobility, were not considered to be contrary to normal targec
behav-ior.
In the following section cases of particular interest are treated
in detail; tht>st' cases generally fall into one of three categories:
(a) Cases that are good examples of inconsistencies tendlng to
confuse any conclusions that might be arrived at;
(b) Cases that are typical of a sub-group of UFO reports that
have the same probable explanation;
ec) Cases that are difficult or seemingly impossible to explain
in terms of known rhenomena.
2. Presentation of Radio Refractive Index Data
Two methods of presenting vertical profi les of Tadi 0 rcfractivj ty
in graphical form are used in this chapter. Roth methods are based
on the use of the radio refractivity, N, 'J/here
6
N ~ (n - 1) x 10 •
since the radio refractive index, n, is always very close to unity
in the atmosphere. The maximum value of N that is likely to be
encountered jn the atmosphere is not much over 400; values close to
500 may occasionally be experienced over the surface of the Dead Sea,
1200 ft. below sC'a level, in rhe summer months.
A f::-ature of all vertical profiles of N is a ):;eneral dec:rease
with height; the departures of any given profile from the average
decrease with height are the significant feature3 for anomalous
propagation of radio waves. lberefore the refractive i~dex profiles
illustrated for many of the UFO cases ill tho fo11o",in", secti0n arc
given in term:; of A-units (Rean. 1966a) where
176