Abstract: Provided herein is a compact and economical direction finding antenna using a mono-pulse antenna system, where a plurality of antenna elements are disposed in a circular array. The directional antennas may be formed by any type of antenna element, including a patch or reflector. The antenna beams of the directional antenna elements overlap, so that from any azimuthal direction, the point is covered by more than one antenna beam. Signals from each pair of adjacent antenna elements of the circular array are processed in order to determine the angle of arrival of a received signal.

Abstract: Provided herein is a compact and economical direction finding antenna using a mono-pulse antenna system, where a plurality of antenna elements are disposed in a circular array. The directional antennas may be formed by any type of antenna element, including a patch or reflector. The antenna beams of the directional antenna elements overlap, so that from any azimuthal direction, the point is covered by more than one antenna beam. Signals from each pair of adjacent antenna elements of the circular array are processed in order to determine the angle of arrival of a received signal.

Abstract: A self-contained data acquisition unit is provided for acquiring seismic data. The unit has a microprocessor and an antenna adapted to receive an electromagnetic signal. A decoder is connected with the microprocessor and adapted to convert received electromagnetic signals to dual-tone multiple-frequency (“DTMF”) digits. A geophone interface is provided with a geophone for collecting acoustic data incident on the geophone. A memory is connected with the geophone interface for storing a representation of the collected acoustic data and for storing a representation of a reference electromagnetic signal to be used in synchronizing acoustic data collected by other data acquisition units. A battery power source is connected with the microprocessor.