Recent research in unattended ground sensor (UGS) systems has established the basis for significant advances in determining the local conditions in a tactical battlefield environment. In particular, new technology allows the creation of `throw-away' sensors which can be placed in a battlefield environment and are capable of self-location (via low cost global positioning satellite system technology), self-calibration using a portfolio of sensors to monitor the local environment, and inter-sensor site communications, e.g. via low level commercially available ethernet spread spectrum transceivers and peer-to-peer networking. At the Penn State University Applied Research Laboratory, such a capability has been developed and demonstrated at the breadboard level. Each node of a multi-node system involves a suite of sensors for acoustic/seismic target identification, sound propagation monitoring (depends greatly on weather conditions), barometric pressure, relative humidity, air temperature vertical gradient, wind, soil temperature, moisture, salinity, dielectric constant, and resistance. A small network of UGS nodes can be distributed widely in an array for non-line-of-sight target identification and tracking as well as real time characterization of the battlefield environment. This paper briefly describes the UGS implementation and unclassified experimental results showing a significant impact of the changing environment of acoustic detection.