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

where $ \frac{\dagger dp}{dt}>\left(\frac{dp}{dt}\right)_{c} $ is the time during which pressure change of the air surrounding the balloon is greater than a design value of pressure change causing ballast flow.

The general equation, then, indicates the relationships between the variables involved in balloon flight. The discussions in this section of the report, "Equations and Theoretical Considerations," attempt to qualitatively organize the relationships between these variables in order that a complete overall picture of the aspects of balloon flight can be formulated.

It should be stressed that the theoretical relationships as stated here do not lend themselves to simple insertion into an overall equation which is easily solved. Rather, solutions of many of the variables are in themselves complex. At this time it appears impractical to delve too deeply into such matters as "the variation of diffusion and leakage through various types of balloons under different conditions" or "a study in the change of coefficient of drag on a balloon system at all points during its flight." It has been more practical to generally state the relationships in unsolved form and concentrate the experimental portion of the research problem on such matters as actual development of balloon controls.

## V. TELEMETERING

## A. Information Transmitted

The need for a balloon-borne transmitter and some system of ground receiving and recording was recognized early in the work of the project. The primary objective of such telemetering was to collect data to evaluate the altitude controls applied to the balloon system. Pressure, perhaps the most important data, was measured by the use of radiosonde-type aneroid capsules. A discussion of the pressure modulators used is given in the following section.

A second use of air-borne transmitters was to provide a beacon for radio direction-finding. With proper equipment a balloon-borne transmitter can provide a signal to guide an aircraft, homing with a radio compass, or provide a position "fix" by the crossed azimuths of ground receiving stations.

In addition to these two very important functions of altitude determination and positioning, telemetering systems were used to detect and transmit temperature data and ballast flow data. The equipment used for these purposes is described below.