An earth penetrating apparatus includes a cutting tool and a sensor
housing. A radar unit, rate sensor unit, processor, and transmitter are
provided in the sensor housing. An antenna arrangement is coupled to the
radar unit and configured for transmitting and receiving electromagnetic
signals in a relatively forward and/or lateral looking direction relative
to a distal end of the cutting tool. The rate sensor unit may include one
or both of a gyroscope and an accelerometer. The processor receives radar
data from the radar unit indicative of subsurface strata and obstacles
respectively located generally forward and/or lateral of the cutting
tool, and receives displacement data from the rate sensor unit indicative
of one or both of longitudinal and rotational displacement of the cutting
tool. The transmitter is configured for transmitting one or both of the
radar data and the displacement data to an aboveground location.