The Roswell Report: Fact vs. Fiction in the New Mexico Desert

Read from the scan by GLM-OCR; expect the odd misread word.

a) Canvas published literature for such further information as can be gleaned from sound transmission between source and receiver at the earth's surface about variation of sound velocity and sound absorption with altitude. Also canvas meteorological literature for better information about the stratosphere.

b) Assign an officer to search confidential publications on sound ranging and other related subjects for relevant information. This officer should also collect data on sound ranging equipment and personnel in the army which could be assembled for a preliminary test.

c) Make a preliminary measurement using about three sound ranging units on ground as receivers, and bombs dropped or rockets fired upward from a high flying plane, or anti-aircraft shells sent as high as possible as sources. This will not be true sound channel transmission, but rather a refinement of the data collected from audibility of large explosions. By proper interpretation of records from bombs exploded at intervals of a few miles out to 400 or 500 miles, all of the basic information will be made available. By use of techniques which I have used for years on sound transmission through ground and through water, it is possible to calculate the path followed by each sound ray, to find its highest ascent into the stratosphere, and to determine the coefficient of sound absorption.

d) A study of existing publications should be made to determine the sound production of typical rocket and jet propulsion units in order to have data about the intensity and the frequency distribution of these sources for ultimate estimates of sound channel range.

If these data do not exist, experiments should be made to produce them, for they would certainly be of use in other connections.

e) An estimate of the background noise to be expected at the axis of the sound channel should be made. In my opinion, the principal contributors will be meteors, possibly high-flying normal air traffic, lightning, and anti-aircraft type artillery fire. A considerable body of information could be collected on this subject without experimentation.