Fifteen years ago, the U.S. Army initiated a program
at APL to investigate the development of small platform
transmitter terminals (PTTs) to be tracked by the
French–U.S. Argos–Tiros satellite system.1
Since the
inception of the program, miniaturization has led to the
fielding of transmitters that weigh less than 28 g and
can interface with an array of sensors. Results of field
tests during the late 1980s and early 1990s, examples
of applications, and continued development of the
technology are reported here.
In 1981, the Bird-Borne Program was initiated at
APL to develop a capability to locate (i.e., track) and
monitor small, highly mobile animals on a local, regional,
and global scale. The primary objective of the
Bird-Borne Program and the Remote Environmental
Sensing Technology Program was to develop a satellite
transmitter for the remote tracking and monitoring of
free-ranging animals. Avian species were the focus
because of their relatively small size and high mobility.
Additional focus has been on birds of prey, which are