roswell

td (d 'where 2.1t> !!A_} is the- time during which pressure change of
the airdlurro8h!1~g 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 qualitati~y organize the relationships between these
variables in order t~.t 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 marv of the
variables are ~n themselves complex. At this time it appears im-
practical 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 rr:ore practical to generally state the relationships in
unsolved form and concentrate the experimental portion of the re-
search problem on such :me_tters 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 ~ork of the pro-
ject. The primary objective of such telemetering was to collect
data to evaluate the altitude controls applied to the balloon sys-
tem. Pressure, perhaps the most irr:portant 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 azi-
muths of ground receiving stations.
In addition to these two very important functions of altitude
dete~.ination 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.
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