The development, testing and evaluation of digital signal processing algorithms can lead to cumbe... more The development, testing and evaluation of digital signal processing algorithms can lead to cumbersome programming problems if these tasks involve extensive data manipulations and interactions with other existing software. When this is the case, there is a need for an interactive software tool that allows flexibility of data and algorithm manipulations and relieves the system designer of many of these
Unmanned/Unattended Sensors and Sensor Networks, 2004
Acoustic sensors have had a long history of use in military applications. Some of the factors fav... more Acoustic sensors have had a long history of use in military applications. Some of the factors favoring their use are: their ability to exploit loud and distinctive emissions of vehicles and weapons firings, their capability to detect and track targets in non line-of-sight conditions, and the ability to carry out their mission in a totally passive way (no emissions to give out their position). Acoustic-seismic sensors can also be implemented using low-power electronics. Acoustic-seismic sensors are now found in various surveillance sensors, generally known as Unattended Ground Sensors or UGS. The trend towards increasing computational capabilities, lower power consumption and better communications capacity have made these devices more useful and acceptable in a variety of military and peace-keeping operations. The promise of networked sensors has opened the possibility of large-scale sensor networks. However, we must be realistic about what can and cannot be achieved within the current technical horizon. The dream of “sensor dust”: miniature devices, built and deployed at minimum cost, transmitting volumes of data is at present, just that, a dream that has to be tempered with the realities imposed by physics.
Unattended Ground Sensor Technologies and Applications VII, 2005
In this paper we examine the different functions performed by an acoustic-seismic unattended grou... more In this paper we examine the different functions performed by an acoustic-seismic unattended ground sensor (UGS) and how they contribute to the overall cost of the sensor and its implementation. A key point made is that the performance of the acoustic-seismic depends on target characteristics and environmental conditions and cannot easily be traded off against implementation costs. At the present time, sensor implementation costs are dominated by the radios. In general, it is best to use radios whose range is consistent with the detection capabilities of the sensors. Dense networks of sensors using short-range radios supporting distributed communication architecture will produce an unnecessary duplication of coverage and a much-increased cost. Different scenarios for the utilization of acoustic-seismic UGS are examined, and evaluated with respect to their implementation costs. The most cost-effective use of acoustic-seismic sensors is in those applications where they can use satellite communications or tap into an existing communications network.
Most designs for acoustic sensors perform some relatively simple level-based detection operation ... more Most designs for acoustic sensors perform some relatively simple level-based detection operation before applying more intensive resources to track the evolution of the target signature. This approach, followed in order to maintain false alarms at an acceptable level, results in the loss of information that could be derived while the signal is at levels below a set detection threshold and can result in missed or late opportunities for the all-important imaging sensors. The track-before-detect approach exploits the use of considering multiple data association alternatives forming potential tracks at low signal to noise ratios that get filtered on the basis of track dynamics to maintain an acceptable level of false alarms. This approach preserves the information derived in the early stages of track formation leading to a more complete exploitation of the available signal and result in earlier maturation of the track.
ICASSP '78. IEEE International Conference on Acoustics, Speech, and Signal Processing
Linear prediction has been established as a reliable and accurate technique for spectrum estimati... more Linear prediction has been established as a reliable and accurate technique for spectrum estimation. One of its most interesting properties is its high resolution. A computer simulation of a signal processor based on this method has been implemented in order to study the errors associated with the estimation of the spectral center frequency of narrow-band processes. Both the Yule-Walker, or correlation method, and Burg's method were considered. The sensitivity of the results was determined for variations in the signal-to-noise ratio, number of samples, process bandwidth and relative center frequency. The results are then compared to lower bounds on spectral center frequency estimation based on periodogram analysis and radar principles.
Border surveillance applications require low false alarm rates and long endurance. These requirem... more Border surveillance applications require low false alarm rates and long endurance. These requirements have not changed since unattended ground sensors (UGS) were first used to monitor Viet Cong activity along the Ho Chi Minh Trail in the 1960's. However the targets are quite different today. Then the targets of interest were large military vehicles with strong acoustic, seismic and magnetic signatures. Currently, the requirements imposed by new terrorist threats and illegal border crossings have changed the emphasis to the monitoring of light vehicles and foot traffic. Unlike with military driven requirements cost of ownership and ease of employment are at least as critical as sensor performance.
Unattended Ground Sensors (UGS) were first used to monitor Viet Cong activity along the Ho Chi Mi... more Unattended Ground Sensors (UGS) were first used to monitor Viet Cong activity along the Ho Chi Minh Trail in the 1960's. In the 1980's, significant improvement in the capabilities of UGS became possible with the development of digital signal processors; this led to their use as fire control devices for smart munitions (for example: the Wide Area Mine) and later to monitor the movements of mobile missile launchers. In these applications, the targets of interest were large military vehicles with strong acoustic, seismic and magnetic signatures. Currently, the requirements imposed by new terrorist threats and illegal border crossings have changed the emphasis to the monitoring of light vehicles and foot traffic. These new requirements have changed the way UGS are used. To improve performance against targets with lower emissions, sensors are used in multi-modal arrangements. Non-imaging sensors (acoustic, seismic, magnetic and passive infrared) are now being used principally as activity sensors to cue imagers and remote cameras. The availability of better imaging technology has made imagers the preferred source of "actionable intelligence". Infrared cameras are now based on un-cooled detector-arrays that have made their application in UGS possible in terms of their cost and power consumption. Visible light imagers are also more sensitive extending their utility well beyond twilight. The imagers are equipped with sophisticated image processing capabilities (image enhancement, moving target detection and tracking, image compression). Various commercial satellite services now provide relatively inexpensive long-range communications and the Internet provides fast worldwide access to the data.
Area Denial concepts, as applied to the next generation of scatterable mines (NGSM), are oriented... more Area Denial concepts, as applied to the next generation of scatterable mines (NGSM), are oriented to the philosophy of greatly reducing the cost and logistics burden of the current family of scatterable mines (FASCAM) while maintaining or improving their effectiveness. By extending the sensing radius of the mines and employing some level of warhead mobility, each mine can protect a larger surrounding area, thus reducing the number of mines required per minefield. ARDEC is currently investigating short range, low cost, ladar-acoustic hybrid sensors, which would be capable of detecting, classifying, tracking, and selecting the optimal firing path to vehicular targets at various ranges from the sensor. In this concept, the strengths and weaknesses of each sensing mode are designed to complement each other, resulting in improved performance of the integrated product. Design concepts will be described and emphasis will be placed on techniques to detect and track targets despite near ground obstacle and terrain features, which can block line of sight. Experimental results, as available at the time of this paper, will also be presented. Approved for public release; distribution is unlimited.
Technological advances in a number of fields have allowed SenTech to develop a highly capable Una... more Technological advances in a number of fields have allowed SenTech to develop a highly capable Unattended Ground Sensor (UGS) able to perform a number of critical missions such as ground and air vehicle surveillance, personnel detection and tracking and sniper localization. These sensors have also been combined with electro-optic sensors to provide target images and improved tracking accuracy. Processing is
Unattended Ground Sensors (UGS) were first used to monitor Viet Cong activity along the Ho Chi Mi... more Unattended Ground Sensors (UGS) were first used to monitor Viet Cong activity along the Ho Chi Minh Trail in the 1960's. In the 1980's, significant improvement in the capabilities of UGS became possible with the development of digital signal processors; this led to their use as fire control devices for smart munitions (for example: the Wide Area Mine) and later to monitor the movements of mobile missile launchers. In these applications, the targets of interest were large military vehicles with strong acoustic, seismic and magnetic signatures. Currently, the requirements imposed by new terrorist threats and illegal border crossings have changed the emphasis to the monitoring of light vehicles and foot traffic. These new requirements have changed the way UGS are used. To improve performance against targets with lower emissions, sensors are used in multi-modal arrangements. Non-imaging sensors (acoustic, seismic, magnetic and passive infrared) are now being used principally as activity sensors to cue imagers and remote cameras. The availability of better imaging technology has made imagers the preferred source of "actionable intelligence". Infrared cameras are now based on un-cooled detector-arrays that have made their application in UGS possible in terms of their cost and power consumption. Visible light imagers are also more sensitive extending their utility well beyond twilight. The imagers are equipped with sophisticated image processing capabilities (image enhancement, moving target detection and tracking, image compression). Various commercial satellite services now provide relatively inexpensive long-range communications and the Internet provides fast worldwide access to the data.
The development, testing and evaluation of digital signal processing algorithms can lead to cumbe... more The development, testing and evaluation of digital signal processing algorithms can lead to cumbersome programming problems if these tasks involve extensive data manipulations and interactions with other existing software. When this is the case, there is a need for an interactive software tool that allows flexibility of data and algorithm manipulations and relieves the system designer of many of these
Unmanned/Unattended Sensors and Sensor Networks, 2004
Acoustic sensors have had a long history of use in military applications. Some of the factors fav... more Acoustic sensors have had a long history of use in military applications. Some of the factors favoring their use are: their ability to exploit loud and distinctive emissions of vehicles and weapons firings, their capability to detect and track targets in non line-of-sight conditions, and the ability to carry out their mission in a totally passive way (no emissions to give out their position). Acoustic-seismic sensors can also be implemented using low-power electronics. Acoustic-seismic sensors are now found in various surveillance sensors, generally known as Unattended Ground Sensors or UGS. The trend towards increasing computational capabilities, lower power consumption and better communications capacity have made these devices more useful and acceptable in a variety of military and peace-keeping operations. The promise of networked sensors has opened the possibility of large-scale sensor networks. However, we must be realistic about what can and cannot be achieved within the current technical horizon. The dream of “sensor dust”: miniature devices, built and deployed at minimum cost, transmitting volumes of data is at present, just that, a dream that has to be tempered with the realities imposed by physics.
Unattended Ground Sensor Technologies and Applications VII, 2005
In this paper we examine the different functions performed by an acoustic-seismic unattended grou... more In this paper we examine the different functions performed by an acoustic-seismic unattended ground sensor (UGS) and how they contribute to the overall cost of the sensor and its implementation. A key point made is that the performance of the acoustic-seismic depends on target characteristics and environmental conditions and cannot easily be traded off against implementation costs. At the present time, sensor implementation costs are dominated by the radios. In general, it is best to use radios whose range is consistent with the detection capabilities of the sensors. Dense networks of sensors using short-range radios supporting distributed communication architecture will produce an unnecessary duplication of coverage and a much-increased cost. Different scenarios for the utilization of acoustic-seismic UGS are examined, and evaluated with respect to their implementation costs. The most cost-effective use of acoustic-seismic sensors is in those applications where they can use satellite communications or tap into an existing communications network.
Most designs for acoustic sensors perform some relatively simple level-based detection operation ... more Most designs for acoustic sensors perform some relatively simple level-based detection operation before applying more intensive resources to track the evolution of the target signature. This approach, followed in order to maintain false alarms at an acceptable level, results in the loss of information that could be derived while the signal is at levels below a set detection threshold and can result in missed or late opportunities for the all-important imaging sensors. The track-before-detect approach exploits the use of considering multiple data association alternatives forming potential tracks at low signal to noise ratios that get filtered on the basis of track dynamics to maintain an acceptable level of false alarms. This approach preserves the information derived in the early stages of track formation leading to a more complete exploitation of the available signal and result in earlier maturation of the track.
ICASSP '78. IEEE International Conference on Acoustics, Speech, and Signal Processing
Linear prediction has been established as a reliable and accurate technique for spectrum estimati... more Linear prediction has been established as a reliable and accurate technique for spectrum estimation. One of its most interesting properties is its high resolution. A computer simulation of a signal processor based on this method has been implemented in order to study the errors associated with the estimation of the spectral center frequency of narrow-band processes. Both the Yule-Walker, or correlation method, and Burg's method were considered. The sensitivity of the results was determined for variations in the signal-to-noise ratio, number of samples, process bandwidth and relative center frequency. The results are then compared to lower bounds on spectral center frequency estimation based on periodogram analysis and radar principles.
Border surveillance applications require low false alarm rates and long endurance. These requirem... more Border surveillance applications require low false alarm rates and long endurance. These requirements have not changed since unattended ground sensors (UGS) were first used to monitor Viet Cong activity along the Ho Chi Minh Trail in the 1960's. However the targets are quite different today. Then the targets of interest were large military vehicles with strong acoustic, seismic and magnetic signatures. Currently, the requirements imposed by new terrorist threats and illegal border crossings have changed the emphasis to the monitoring of light vehicles and foot traffic. Unlike with military driven requirements cost of ownership and ease of employment are at least as critical as sensor performance.
Unattended Ground Sensors (UGS) were first used to monitor Viet Cong activity along the Ho Chi Mi... more Unattended Ground Sensors (UGS) were first used to monitor Viet Cong activity along the Ho Chi Minh Trail in the 1960's. In the 1980's, significant improvement in the capabilities of UGS became possible with the development of digital signal processors; this led to their use as fire control devices for smart munitions (for example: the Wide Area Mine) and later to monitor the movements of mobile missile launchers. In these applications, the targets of interest were large military vehicles with strong acoustic, seismic and magnetic signatures. Currently, the requirements imposed by new terrorist threats and illegal border crossings have changed the emphasis to the monitoring of light vehicles and foot traffic. These new requirements have changed the way UGS are used. To improve performance against targets with lower emissions, sensors are used in multi-modal arrangements. Non-imaging sensors (acoustic, seismic, magnetic and passive infrared) are now being used principally as activity sensors to cue imagers and remote cameras. The availability of better imaging technology has made imagers the preferred source of "actionable intelligence". Infrared cameras are now based on un-cooled detector-arrays that have made their application in UGS possible in terms of their cost and power consumption. Visible light imagers are also more sensitive extending their utility well beyond twilight. The imagers are equipped with sophisticated image processing capabilities (image enhancement, moving target detection and tracking, image compression). Various commercial satellite services now provide relatively inexpensive long-range communications and the Internet provides fast worldwide access to the data.
Area Denial concepts, as applied to the next generation of scatterable mines (NGSM), are oriented... more Area Denial concepts, as applied to the next generation of scatterable mines (NGSM), are oriented to the philosophy of greatly reducing the cost and logistics burden of the current family of scatterable mines (FASCAM) while maintaining or improving their effectiveness. By extending the sensing radius of the mines and employing some level of warhead mobility, each mine can protect a larger surrounding area, thus reducing the number of mines required per minefield. ARDEC is currently investigating short range, low cost, ladar-acoustic hybrid sensors, which would be capable of detecting, classifying, tracking, and selecting the optimal firing path to vehicular targets at various ranges from the sensor. In this concept, the strengths and weaknesses of each sensing mode are designed to complement each other, resulting in improved performance of the integrated product. Design concepts will be described and emphasis will be placed on techniques to detect and track targets despite near ground obstacle and terrain features, which can block line of sight. Experimental results, as available at the time of this paper, will also be presented. Approved for public release; distribution is unlimited.
Technological advances in a number of fields have allowed SenTech to develop a highly capable Una... more Technological advances in a number of fields have allowed SenTech to develop a highly capable Unattended Ground Sensor (UGS) able to perform a number of critical missions such as ground and air vehicle surveillance, personnel detection and tracking and sniper localization. These sensors have also been combined with electro-optic sensors to provide target images and improved tracking accuracy. Processing is
Unattended Ground Sensors (UGS) were first used to monitor Viet Cong activity along the Ho Chi Mi... more Unattended Ground Sensors (UGS) were first used to monitor Viet Cong activity along the Ho Chi Minh Trail in the 1960's. In the 1980's, significant improvement in the capabilities of UGS became possible with the development of digital signal processors; this led to their use as fire control devices for smart munitions (for example: the Wide Area Mine) and later to monitor the movements of mobile missile launchers. In these applications, the targets of interest were large military vehicles with strong acoustic, seismic and magnetic signatures. Currently, the requirements imposed by new terrorist threats and illegal border crossings have changed the emphasis to the monitoring of light vehicles and foot traffic. These new requirements have changed the way UGS are used. To improve performance against targets with lower emissions, sensors are used in multi-modal arrangements. Non-imaging sensors (acoustic, seismic, magnetic and passive infrared) are now being used principally as activity sensors to cue imagers and remote cameras. The availability of better imaging technology has made imagers the preferred source of "actionable intelligence". Infrared cameras are now based on un-cooled detector-arrays that have made their application in UGS possible in terms of their cost and power consumption. Visible light imagers are also more sensitive extending their utility well beyond twilight. The imagers are equipped with sophisticated image processing capabilities (image enhancement, moving target detection and tracking, image compression). Various commercial satellite services now provide relatively inexpensive long-range communications and the Internet provides fast worldwide access to the data.
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Papers by Gervasio Prado