The objective of this demonstration was to collect unexploded ordnances (UXOs or duds) and fire for effect data and validate Seismic-Acoustic Impact Monitoring and Assessment (SAIMA) capability to automatically detect, classify, and locate UXO and low-order detonations (LOD) impacts on range. The performance objectives for the Phase I Environmental Security Technology Certification Program (ESTCP) work can be summarized as: 

  1. Assess quality of the SAIMA system currently deployed at Ft. Sill;
  2. Collect and analyze data for UXO detections; and
  3. Collect and analyze "fire for effect" for single dud detections.

Technology Description

The SAIMA system consists of a network of seismic-acoustic sensors distributed around an impact range. Each station consists of an array of sensors connecting to a node that processes the signal and transmits the data to a Remote Data Processing Station for display. The number of arrays deployed around the range depends on the size of the range and munitions being detected. A trigger sensor is located near the firing station to detect the muzzle blast and firing times of the munitions.

Seismic-acoustic sensors are buried in shallow holes around the monitored area in a two-dimensional array pattern capable of sensing both seismic and acoustic energy of the munitions impact and detonation. The array design provides an azimuthal direction of the arrival signal that can be associated with multiple arrays by beam crossing and geo-locating the energy source.

Demonstration Results

Firing schedules at Ft. Sill prevented insufficient range access time to install more equipment than was installed. Additional time would have allowed sites to the south and east of the impact area, reducing the propagation path distances and providing better azimuthal resolution. Two arrays were installed and recorded high energy (HE) impacts and inert impacts. For the first time, seismic impacts were observed and utilized to recover impacts from inert rounds, mimicking UXO rounds. This was a major accomplishment for this effort. The artillery officer was unable to provide a "fire for effect" scenario; these data could not be obtained. Without the data, this objective could not be met. Any future work should provide dedicated fire control on the range to obtain the needed data for assessment.

With the prior deployments and success of this last collect to actually detect and locate inert rounds, the SAIMA program has been shown to be a success. Overcoming the issues of sufficient range time to install equipment and to provide a dedicated fire mission to test and demonstrate the automated SAIMA system, should provide a success during the Phase II option.

Implementation Issues

During normal installations, the SAIMA system can be deployed quite easily. Projected times for installation (a rule of thumb) are approximately one day per site. This includes setting the trigger node, all sensors at each array site, remote data processing station (RDPS) site, and array and radio tests between all sites. During this last collect, temporary stations (two arrays and four single channel units) were deployed powered by batteries with no radio signals. All equipment was deployed in one day with explosive ordnance disposal (EOD) support to access the field. In this collect, time to access the range was the issue.