Tests and Evaluation of Dual Sensor Mine Detectors based on a Combination of Metal Detector and Ground Penetrating Radar (TEDS)

Transcription

1 AIDCO-JRC Administrative Arrangement No.: MAP/2004/ Tests and Evaluation of Dual Sensor Mine Detectors based on a Combination of Metal Detector and Ground Penetrating Radar (TEDS) Adam M Lewis Institute for the Protection and Security of the Citizen 2006 EUR EN 1

2 The Institute for the Protection and Security of the Citizen provides research- based, systems-oriented support to EU policies so as to protect the citizen against economic and technological risk. The Institute maintains and develops its expertise and networks in information, communication, space and engineering technologies in support of its mission. The strong cross-fertilisation between its nuclear and non-nuclear activities strengthens the expertise it can bring to the benefit of customers in both domains. European Commission Directorate-General Joint Research Centre Institute for the Protection and Security of the Citizen Contact information Address:TP 723 Centro Comune di Ricerca, Via Enrico Fermi 1, Ispra (VA) Italy Tel.: Fax: Legal Notice Neither the European Commission nor any person acting on behalf of the Commission is responsible for the use which might be made of this publication. A great deal of additional information on the European Union is available on the Internet. It can be accessed through the Europa server EUR EN ISSN Luxembourg: Office for Official Publications of the European Communities European Communities, 2006 Reproduction is authorised provided the source is acknowledged Printed in Italy 2

3 Acknowledgement I would like to thank warmly JRC colleagues Mr D M Shaw and auxiliary staff members Mr D M Guelle and Mr M A Pike. This report draws extensively on their notes and verbal comunications. The project was funded by the EuropeAid Cooperation Office under administrative arrangement MAP/2004/ and by the JRC under Action 4341 Test and Evaluation of Technology for Humanitarian Demining. Executive Summary This document contains two reports from the project Tests and Evaluation of Dual Sensor Mine Detectors based on a Combination of Metal Detector and Ground Penetrating Radar (TEDS). The first report describes demonstrations and basic functional tests of the HSTAMIDS, MINEHOUND, SHRIMT Model 90 and ALIS GPR/MD dual sensor mine detectors. The aim was to give an overall indication of the state of development of this class of instrument. Copies of MINEHOUND and SHRIMT Model 90 were procured for test by the JRC and measurements of the emitted radar signals were made, as well as the basic functional tests. A demonstration of HSTAMIDS AN/PSS14 was conducted for JRC by Cyterra representatives and a demonstration of ALIS by Tohoku University for JRC and ITEP representatives. All tests took place at the JRC s Ispra site in northern Italy during the period November 2003 to January 2006, on the outdoor test lane and in the laboratories. The HSTAMIDS and MINEHOUND detectors were confirmed to be fully developed products with credible performance, the HSTAMIDS being slightly more mature. The SHRIMT Model 90 is a fully developed product but with lesser performance, especially with regard to its radar. ALIS is an advanced concept with very interesting capabilities but at an earlier stage of development. The most important conclusion is that dual sensor technology has moved ahead significantly during the last three years and devices have now reached high levels of technology readiness. Dual sensor remains a leading candidate for improving efficiency, providing that the cost-benefit balance can be shown to be favourable. Further developments in productionization, ergonomics and battery-life would be conducive to the adoption of this technology. The possibility of using separate handheld MD and GPR should also be considered. The second report describes an ITEP-endorsed field trial of the MINEHOUND detector in Bosnia in 2005 to which JRC contributed. The results of this trial were encouraging and the device was well-received by the local deminers. Unfortunately, restrictions on the availability of the systems and test facilities prevented a simultaneous comparative field-trial of MINEHOUND and HSTAMIDS as had originally been planned. On the basis of the work described in these two reports, the following conclusions are drawn. Systematic test and evaluation must continue to be considered a priority and is being addressed by the ITEP Multisensor Working Group. A test protocol drafted at JRC has been submitted to them. There has been concern that a premature comparative trial between HSTAMIDS and MINEHOUND could do more harm than good. However, on the evidence seen, it appears these systems are now at the point where a direct comparison would make sense. For further information and copies of this report, please contact Adam.Lewis@jrc.it. 3

4 Table of Abbreviations AIDCO EuropeAid Cooperation Office ALIS Advanced Landmine Imaging System AP Anti-personnnel AT Anti-tank CEN Comité Européen de Normalisation CWA CEN Workshop Agreement ERW Explosive Remnants of War EU European Union EC European Commission GC Ground Compensation GICHD Geneva International Centre for Humanitarian Demining GPR Ground Penetrating Radar HSTAMIDS Handheld Standoff Mine Detector System ITEP International Test and Evaluation Program ITOP International Test Operation Procedures JRC Joint Research Centre of the European Commission MD Metal Detector MsMs Multisensor Mine Signatures MSWG Multisensor Working Group SHRIMT Shanghai Research Institute for Microwave Technology STEMD Systematic Test and Evaluation of Metal Detectors TEDS Test and Evaluation of Dual Sensors 4

5 AIDCO-JRC Administrative Arrangement No.: MAP/2004/ Tests and Evaluation of Dual Sensor Mine Detectors based on a Combination of Metal Detector and Ground Penetrating Radar (TEDS) Report of the Laboratory Tests Adam M Lewis Institute for the Protection and Security of the Citizen 6th October

6 1. Introduction The second project agreed under the Administrative Arrangement between AIDCO and JRC concerns Test and Evaluation of MD/GPR Dual Sensors, mine-detectors which incorporate a ground penetrating radar and a metal detector in the same instrument. As originally conceived, this project was intended as a comparative test of the two systems which had been developed at the time. In the event, one of these systems is still considered armaments technology, and is subject to trade restrictions. The JRC was able to procure a copy of the second system, but only after long delay. Therefore, the thorough comparative test which we had hoped to make was not feasible. However, two other systems were available, one for purchase and one for demonstration. It was therefore possible to conduct some tests on all four systems, albeit with much less thoroughness than had originally been intended. Furthermore, the view of several of JRC s partner organisations was that the concept of a rigorous comparative trial was in any case premature, since no system is yet fully developed. This report sets out to describe the available systems and such testing as has been performed. 2. Background 2.a The Dual Sensor Concept When metal detectors were originally developed for detecting landmines, in the Second World War, most mines had substantial metal content. A typical problem would to detect antitank mines consisting of flat metal containers 30cm or more across. In response to the existence of detectors, mine designers steadily reduced the metal content of mines. Detector designers in turn made their instruments more and more sensitive. Modern metal detectors are able to detect mines whose only metal content is a detonator can and a striker pin a few mm across, at depths up to 20cm. There is, however, a fundamental drawback to increasing the detector sensitivity. Soil in any area which has been inhabited invariably contains many small pieces of metallic debris: wherever there are people, there is metal in the ground. It is impossible, with a metal detector alone, to distinguish nails, bits of fence wire, coins, bottle-caps and cigarette-foil from low-metal mines. In a typical manual demining operation, many hundreds of innocuous pieces of metal are found for each mine, each one must be assumed dangerous until it has been carefully excavated. Although the metal detector remains the only electronic sensor in widespread-use for demining, it is not a satisfactory sensor. Ground penetrating radar differs from a traditional metal detector in using much higher frequencies: greater than 300MHz, as opposed to less than 100 khz. The plastic materials used in mines do not conduct electricity and do not influence a magnetic field, so they are not detected by metal detectors. But they are polarized by electric fields and this has an effect on electromagnetic fields which is significant at high frequencies. Plastic mines and explosives can therefore be detected by the GPR. However, GPR is even more susceptible to false alarms than metal detectors, since every tree root, stone or region of dryness or wetness in the soil has a similar effect. For this reason, GPR by itself has not found much success as a mine detector. A landmine will be detected by the GPR providing the signal penetrates deeply enough into the soil and it will usually contain metal and cause a response in a metal detector as well. If both GPR and MD are incorporated in the same device, it is possible to detect metal objects and distinguish those which cause a GPR response, such as mines, from those which do not, such as many scrap metal items. It will not be possible to completely avoid false alarms, because some scrap items will also cause a response in the 6

7 GPR, e.g. an empty drink can or a nail next to a stone. Nevertheless, the dual sensor idea presents the possibility of radically reducing the number of false alarms which have to be excavated. A distinction should be drawn between two types of dual sensor devices. The simpler type are those which consist of two sensors fitted into the same unit, each presenting their signals separately to the operator. The more sophisticated type combine the signals from the two sensor to form a single output, a process known as data fusion. 2.b Detectors Available Two systems were identified in the TEDS work plan, one from UK and one from Germany: HSTAMIDS (handheld standoff mine detection system) manufactured by L-3 Cyterra of Waltham, Massachusetts USA. This device incorporates a metal detector manufactured by Minelab Pty. Ltd. of Australia, who act as a supplier only. The signal from the metal detector is used to trigger the GPR, which consitutes the simplest form of data fusion. This device has subsequently been made in two versions, a military version known as AN/PSS14, now in use by US and some allied armies, and a humanitarian version designated AMD14. MINEHOUND manufactured by ERA Technology Ltd. of Leatherhead UK. The metal detector is made by Vallon GmbH of Eningen, Germany, who are a partner in the project. The signals are presented separately without fusion. Subsequently, the following systems were also identified: Shanghai Research Institute for Microwave Technology, Model 90. This low-cost device is sold as a commercial product. It incorporates a 369MHz UHF radar and a metal detector. The signals are presented separately without fusion. ALIS Advanced landmine imaging system, developed by Tohoku University Sedai, Japan. It incorporates a metal detector made by CEIA SpA of Arezzo, Italy. PHMD Portable Humanitarian Mine Detector is a concept demonstrator developed by Qinetiq in UK. With the exception of the SHRIMT Model 90, all these devices have been described in the recently published GICHD guidebook [ref. Guide GICHD]. Each system is assessed in its level of technology readiness according to a numbering system used for defence procurement, in which Level 1 is least developed and 9 most developed. The assessment was as follows: AN/PSS-14 Level 9: System accredited through successful mission operations AMD14, MINEHOUND Level 8: System completed and qualified through test and demonstration ALIS, PHMD Level 6: Prototype demonstrated in a relevant environment 7

8 The SHRIMT Model 90 should be considered at least Level 8, since it is a fully worked up commercial model. It may, in fact, be Level 9, if it has been used by the Chinese military in successful operations; this is unknown to the authors. 2.c Previous EC-funded work on multisensor mine detection Several research projects in the Fourth and Fifth Framework programmes addressed the question of dualsensor mine detection. Some of these were more ambitious technologically, at a research level, examining also multi-sensor systems incorporating other detection modes such as acoustic, infrared and passive microwave devices. The JRC played a test and evaluation role in this programme and most of the prototypes were exercised on the test lane at Ispra during Some research into data fusion was also conducted. MACADAM FP4 Esprit LOTUS FP4 Esprit PICE FP4 Esprit INFIELD FP4 Esprit HOPE FP4 Esprit DEMAND FP5 IST MsMs JRC institutional project The two companies who built the MINEHOUND dual-sensor detector were participants in some of these projects. Vallon GmbH participated in the HOPE project and a Vallon detector was used in MsMs. ERA Technology Ltd. participated in INFIELD and were a contractor in MsMs, an ERA GPR was included in MACADAM. The experience gained led to the realisation that development costs for a complex multi-sensor system incorporating state of the art data-fusion knowledge would be unrealistically high for humanitarian demining. It was necessary to begin with the more modest goal of building a working, handheld dualsensor device. The MINEHOUND detector is the realisation of this concept. 8

9 3. Tests and demonstrations at JRC 3.a HSTAMIDS HSTAMIDS is subject to the US ITAR (International Trade in Arms Regulation). Correspondence with Cyterra revealed that this restriction applied to the humanitarian AMD14 version as well as the military AN/PSS14. It is not possible to procure a copy for test and evaluation and then openly publish the results. The only possibilities are demonstration by Cyterra staff, military test with reports classified, and application to US Dept. of State for de-classification of a report. A demonstration was conducted at JRC by Cyterra in November Method The PSS14 was demonstrated on the main test lane at the Ispra site, and on two side lanes with various mines and clutter objects. Results In accordance with the terms of the license, no publication of the results is possible. 9

10 3.b MINEHOUND General Two JRC auxiliary engineers were trained in the use of the Minehound at JRC premises at the end of June 2005, in preparation for attending field trials. In the event only one of the auxiliaries attended the field trial (see separate report). A copy of the ERA Minehound was ordered by the JRC but did not arrive until January By then, the JRC s Action on Test and Evaluation of Technology for Humanitarian Demining had formally ended so no JRC permanent staff resources were available to test it. The two auxiliary engineers were almost fully-occupied with metal detector trial work but they were able to devote a little time to a preliminary examination of the dual sensor. Preliminary tests were conducted which confirmed that the device functioned correctly and was able to detect targets in the test lane and in the Gauss lab sand pit. Due to the ending of the auxiliary contracts, unfortunately no further work has been possible. Radio frequency analysis The Minehound signal is described [ref. MH SPIE] as pulses of 1ns duration repeating at 1MHz. Theoretically, this should have a broadband spectrum multiplied by a comb function. The output seen on a handheld spectrum analyzer is as shown in fig. 1. The main curve shows the broadband envelope. The frequency comb is visible on the inset plot, where the analyzer was set to zoomin on a short section of the frequency range. Minehound Spectrum Sig at 10cm (dbm) freq (MHz) Fig. 1 Output spectrum of MINEHOUND GPR. (PSA 1301T portable spectrum analyzer, 10cm away). 10

11 Proposed modifications In 2006 ERA wrote to JRC to say that, following the field trials, they would like to make further modifications to the copy held by JRC: 1. MD cable replacement to improve its sensitivity and stability 2. Low power improvement to reduce the power consumption from 9W to 6W 3. Increase in GPR temperature performance from 35 C to 50 C 4. Software upgrade to enable adjustment of the gain and the start point of the received signal using the control handle and remove the need to use a laptop. 3.c SHRIMT Model 90 General The GPR incorporated in the Shanghai Research Institute for Microwave Technology Model 90 is of lower frequency than the wide band devices used in MINEHOUND and HSTAMIDS and has considerably lower sensitivity. The manual claims detection of AP mines by the GPR at only 2cm depth but its price is also very much lower Two copies were procured by the JRC in November The metal detector component of the SHRIMT model 90 was also fully evaluated in the STEMD project [refs. STEMD Moz, STEMD Lab]. Radio frequency analysis The Chinese mine detector when switched on produces a low power radio signal in the lower U.H.F. Band. The carrier frequency range is about between 369MHz and 378MHz. ( Ground contact to freespace frequencies respectively). There is a double sideband amplitude modulation signal at about 23 khz. Fig. 2 Radio frequency output spectrum from SHRIMT Model 90. (HP8565E Microwave Spectrum Analyzer, with sub-resonant E-field probe, approximately 1 metre away). The large peak on the left is the UHF signal; the small peak on the right is a 23 khz amplitude modulation. 11

12 This shows the R.F. carrier frequency to be about 369 MHz in the fully dielectrically loaded position. i.e. the detector head placed on a carpeted and concrete floor. (This was necessary as the R.F. oscillator frequency output is free-running or at least very mobile and shifts markedly depending on the surrounding objects). No evidence of Frequency Modulation or Pulse Modulation of any kind was seen, in contrast to the MINEHOUND. On a high speed oscilloscope coupled inductively to the head, the only significant low frequency signal visible is a 23 khz signal additive to the UHF signal, rather than modulating it. This appears to be the metal detector signal, since the manual states that a sinusoidal signal is used to run the metal detector sensor and 23 khz would be a reasonable choice of frequency for it. Therefore, the sidebands in the UHF signal seem to be caused by unintentional mixing of the metal detector signal into the UHF circuit. Whilst free-space running some 3rd and 4th R.F. harmonics of 378 MHz at 1.134GHz and 1.512GHz were seen, approximately 40dB below the carrier frequency. No strong 2nd harmonic was seen. No spurii were observed and the detector tuned across its frequency band in a clean and smooth manner. This indicates a reasonably good R.F system design using linear components and well adjusted. The same spectrum was seen irrespective of the Switch Position: M, C1 and C2 positions seemed to generate the same output. No changes in carrier frequency, amplitude or modulation were noticed in the combined or metal positions. Similarly, the sensitivity control would seem to work mostly within the control unit as the relative amplitudes of the observed waveforms were stable irrespective of the operator adjustment of any/all of the controls. Fig. 3 Model 90 detector, controller and headset, and an ITOP surrogate antitank mine. DC Power The unit is powered by quantity ten (10) standard alkaline AA/MN1500 batteries, hence has an available power footprint of 16 to 12 volts. The measured lifetime in the STEMD lab tests [ref. STEMD Lab] was 49hrs with high quality alkaline cells, indicating a current drain of about 20mA. This suggests reasonably advanced integrated electronics technology, as the DC power available in the controller is less than 0.5 watt. 12

13 Model 90 Detection System Characteristics With a plastic antipersonnel mine moved very near the detector head, the R.F. carrier showed an approximate negative 1 MHz shift from the measured free space R.F. carrier of about MHz to about 375MHz. With a smaller linear metallic object the delta frequency seen was from about MHz to about MHz. 3.d Advanced Landmine Imaging System (ALIS) General ALIS is a dual-sensor mine detector, developed by Prof. Sato of the Centre for Northeast Asian Studies (CNEAS- Tohoku University, Japan) and funded by the Japanese Science and Technology Institute (JST), Ministry of Education, Culture, Sports, Science and Technology (MEXT). ALIS currently combines a COTS metal detector (CEIA MIL-D1) and an in-house developed impulse radar system, which operates at a frequency range of 1 GHz - 3 GHz. The GPR antennas are mounted in front of the MD (Fig. 4), instead of being co-located with the MD, as is the case for the HSTAMIDS and MINEHOUND systems. The GPR antennas add more or less 1 kg to the weight of the MD. We were unaware of the existence of this device at the time the TEDS project was planned but it was considered appropriate to include it in the project, so ALIS was demonstrated in April 2005 at Ispra. ALIS includes a positioning system which works by processing the image from a visible light camera. In this way, it is possible to obtain images from a handheld detector. A commercial handheld visual display was also connected to the system so the images could be seen in real-time. Fig.4 Left View of ALIS detector, with backpack and umbilical. Right Detail of ALIS head showing twin cylindrical GPR antenna mounted in front of CEIA MIL D1 metal detector coil Fig. 5 ALIS detector demonstration by Tohoku University at JRC in April 2005, attended by representatives of ITEP 13

14 Fig. 6 shows the images of the data. Many clutter objects appear in the GPR images. However it is possible to determine the buried location of the landmine surrogate by observing both the metal detector and GPR images. Fig. 6 Metal detector and ground penetrating radar images prepared by Tohoku University from their demonstration at JRC. 14

15 3.e Portable Handheld Mine Detector (PHMD) Fig. 7. The PHMD was tested in the USA in Qinetiq decided to concentrate on their test and evaluation role, providing the UK representatives on ITEP and leading the field test and evaluation of MINEHOUND. JRC wrote to Qinetiq to enquire if there were plans to manufacture PHMD and, after confirmation in November 2004 that it was not going into production, it was excluded from the TEDS project. 4. Test Protocol The original plan was to agree a test protocol with a panel of scientific experts and then conduct the comparative test according to it. As explained above, we did not have access to the systems to make the comparative test, nevertheless, a test protocol was drafted at the JRC at the end of An obviously suitable panel of experts had by then already been established: the ITEP Multisensor Working Group, whose members had begun to work on relevant ideas [refs. Test prot TNO, Test Prot Qine]. Therefore, the JRC protocol was submitted to them for discussion [ref. Test Prot JRC]. In summary, the general approach is to follow the model of CEN Workshop Agreement CWA 14747:2003 for metal detectors, retaining relevant sections unchanged and modifying or adding sections as needed specifically for dual sensors. A key problem to address is the establishment of a neutral environment for testing the radar element. For metal detectors, in-air tests are used as a baseline to assess the effects of various factors (e.g. sweep speed, metal content, drift, repeatability, temperature etc.) which may affect the sensitivity. This is not possible for radar because two key properties: the power reflected back from the soil surface and absorption of the beam by the soil, are not present in an in-air test. Therefore some other neutral controlled environment must be used. One possibility is to use microwave absorbing foam as a medium. Another would be a liquid medium such as saline water. In the opinion of the present author, the latter would be less convenient because hundreds of kilos of electrolyte would be needed. 15

16 5. Conclusions and lessons learnt Compared with the state of development at the start of the TEDS project, both HSTAMIDS and MINEHOUND have moved forward considerably and are now operational devices. From all information available, both appear to be highly credible. The Model 90 cannot be compared with them because it is much less sensitive. The GPR component appears to have very limited performance. However, the fact that such a sophisticated device as a dualsensor mine detector could be produced at all in China is very significant. The ALIS concept is much more ambitious and remains of high interest in spite of being at an earlier stage of development. In particular, the realisation of an imaging system without mechanical scanning is impressive. The value of the dual-sensor concept has received criticism [ref. Smith] on the grounds that GPR used to reject clutter can never find a mine that the metal detector did not find. Since the GPR will inevitably have a probability of detection less than 100%, introduction of dual-sensor will lead to more missed mines. In reply to this argument, it should be said that it assumes an unrealistically idealised picture of the manual demining process; in which deminers are never less than perfectly diligent in excavating metal detector indications, never make a judgement that an indication is from an innocuous source and never reduce sensitivity to reduce clutter signals. In reality, all these things happen. Dual-sensor technology offers the potential for using metal detectors at higher sensitivity settings without ignoring indications, so that there would be fewer missed mines. Comparison of probabilities of detection and false alarm rates for single-sensor MD versus dual sensor GPR/MD can only be determined by rigorous field trials, it cannot be inferred from a priori arguments. The cost of the leading systems is at present about 4 to 8 times that of a good metal detector. Their value in humanitarian demining will depend on whether the advantages of using a dual sensor device are sufficient to compensate for the price multiple. Production in higher volumes, design-for-production, the use of common components for military and humanitarian versions and the availability of cheaper radio frequency components from consumer applications are likely to reduce the price multiple in future, making dual sensor technology relatively more attractive. Equally important will be the fully realisation of the benefits of the technology by learning to use it in the best way. A very important unanswered question is whether there is a real advantage to using a data fusion system, either of the elementary form used in the present HSTAMIDS devices or of a more sophisticated form. It might be argued that a device such as MINEHOUND, which presents the signals completely separately without fusion, is just an electronically complicated way of using separate handheld MD and GPR. However, there is a distinction between a device or method which presents signals from two sensors simultaneously and one which presents them one after the other, because in the the former case, it is much easier for the operator to mentally fuze the data The possibility that using separate MD and GPR [ref. Pike] might indeed be an attractive option seems to have received surprisingly little attention. The advantages would be that organisations could continue to use their existing metal detect fleet, it would only be necessary to procure relatively cheap GPR-only units, the extra development costs associated with combining two sensitive electronic instruments in one package would be removed and there would be more flexibility to upgrade to newer MD or GPR as these became available. The disadvantages would be that using two separate instruments would be unwieldy, especially if one tried to use them simultaneously, and training and maintenance costs might be higher. The possible option of using separate MD and GPR handheld units should also be considered in future evaluations, especially with regard to cost/benefit in comparison with a fully integrated dual sensor 16

17 employing data fusion. Careful consideration of how two separate sensors might be carried and used by a deminer would be needed. Although the dual-sensor concept was motivated mainly by the desire to address the minimum metal antipersonnel mine problem, arguably the most impressive results from dual sensors have been on minimum metal antitank mines. It should be emphasised that AT mines are as much of a humanitarian problem as AP, since they can obstruct key post-conflict activities such as the provision of supplies, the return of displaced persons and the movement of materials for reconstruction. Modern minimum-metal antitank mines can be even more difficult to detect than antipersonnel mines, since they are usually buried more deeply. Even a relatively unsophisticated dual-sensor such as the Model 90 could potentially be of use for detection of such mines. 17

18 1.a. Specifications and photographs of developed systems ERA / Vallon MINEHOUND Operational aspects Format Single piece, electronic compartment mounted on handle Head 31 x 17 cm Truncated ellipse Length in use 99cm-143cm Continuously adjustable Mass in use Ground compensation Mode Audio Target signals System signals 4.75kg Yes Dynamic MD Dynamic GPR Internal speaker / earpiece, switchable for muting or non-muting Different pitches and tones for GPR and MD Low battery alarm Controls Switch Normal, Mineralised, GPR and MD vol. adjust Access to software Yes Price EUR Without VAT 2005 Package Operator manual No Instruction card No List of contents No Test piece Yes One GPR, one MD Batteries Yes NiMH rechargeable Transport case Dimensions cm Mass (full) 8.3 kg Type material Semi-rigid foam/vinyl Backpack Case may be worn as a backpack Mass backpack (full) 8.3kg Times for Set up Mechanical set-up 30 s Backpack storage 65s Standing/kneeling 10 s Electrical set-up 10 s Electrical aspects MD Waveform Bipolar pulses Coils Single coil GPR Waveform Pulsed 1ns duration, 1 MHz repetition frequency Battery Type - Number 4 NiMH D-cells 6V nominal Life 2 hrs Stated by ERA, not verified 18

19 ERA / VALLON MINEHOUND 19

20 Shanghai Research Institute of Microwave Technology, Model 90 Operational aspects Format Two-piece, screw lock, separate control box Head 26 cm side Square Length in use cm Continuously adjustable Mass in use Ground compensation Mode Audio Target signals 3.3 kg No Dynamic Headphone Audio System signals Audio Confidence click, low battery alarm Controls Access to software On/off/mode select Volume No Metal detector only, two dual-sensor modes Price 980 EUR Without VAT 2004 Package Operator manual Yes A5, English, paper Instruction card No List of contents No Test piece No A prodder is also supplied Batteries Yes Transport case Dimensions 55 x 32 x 16 cm Mass (full) 9 kg Type material Hard metal Backpack Yes Mass backpack (full) 4.25 kg Times for Set up Mechanical set-up 130 s Backpack storage 70 s Standing/kneeling 20 s Electrical set-up 18 s Electrical aspects MD Waveform Single sine wave 23kHz Coils Single (?) Inferred from manual, not verified directly GPR Waveform Single sine wave 369MHz Battery Type - Number LR6 (AA) - ten 15V nominal Life 49 hrs Manual states not less than 8 hrs with ZnC 20

21 Shanghai Research Institute for Microwave Technology, Model 90 21

22 HSTAMIDS AN/PSS14 (Military Version) sources [ref. Guide GICHD ] and Cyterra website. Format Two-piece shaft, control box on shaft Head 21cm Ø Circular Length in use Mass in use cm 4.9kg plus battery Ground compensation Yes Patented Minelab multi pulse-width method Mode Audio Target signals System signals Controls Access to software Dynamic MD External speaker or headphones Separate MD and GPR/MD data fusion detection beep Yes Uses electronic voice Price USD For low volume Package Operator manual Instruction card List of contents Test piece Yes Batteries Transport case Dimensions 64 x 53x36 cm Mass (full) 20kg Type material Hard Backpack Yes Mass backpack (full) Times for Set up Mechanical set-up Backpack storage Standing/kneeling Electrical set-up Electrical aspects MD Waveform Pulsed Multi-pulse width Coils Single GPR Waveform 1 to 3 GHz Stepped frequency Battery Type - Number Various standard military battery packs may be used Life 4 hours typical 22

23 HSTAMIDS AN/PSS14 (Military Version) 23

24 HSTAMIDS AMD14 (Humanitarian version) sources [ref. Guide GICHD ] and Cyterra website. Format One-piece, control box on shaft Head 21cm Ø Circular Length in use Mass in use cm 4.9kg inc. battery Ground compensation Yes Patented Minelab multi pulse-width method Mode Audio Target signals System signals Controls Access to software Dynamic MD External speaker or headphones Separate MD and GPR/MD data fusion detection beep Yes Uses electronic voice Price USD For low volume, estimated Package Operator manual Instruction card List of contents Test piece Yes Batteries Transport case Dimensions 95 x 45x25 cm Mass (full) 20kg Type material Hard Backpack Mass backpack (full) Times for Set up Mechanical set-up Backpack storage Standing/kneeling Electrical set-up Electrical aspects MD Waveform Pulsed Multi-pulse width Coils Single GPR Waveform 1 to 3 GHz Stepped frequency Battery Type - Number Various standard military battery packs may be used Life 4 hours 24

25 HSTAMIDS AMD14 (Humanitarian Version) 25

26 6. References [GICHD Guide] [MH SPIE ] [Pike] [Smith] [STEMD Lao] [STEMD Moz] [STEMD Lab] [Test Prot JRC] [Test Prot Qine] [Test Prot TNO ] C Bruschini, A Carruthers, H Sahli, K Koppetsch, J Glattbach and F Jaffré Guidebook on Detection Technologies and Systems for Humanitarian Demining GICHD Geneva, March 2006 ISBN D J Daniels, P Curtis, R Amin and N Hunt MINEHOUND TM Production development Proc. SPIE , pp M A Pike Private Communication 2005 Comment:HSTAMIDS A V Smith D Guelle, A M Lewis, M A Pike, A Carruthers and S Bowen Systematic Test and Evaluation of Metal Detectors (STEMD) Interim Report Field Trial Laos European Commission Joint Research Centre Special Publication SP D M Guelle, A M Lewis, M A Pike and C Craill Systematic Test and Evaluation of Metal Detectors (STEMD) Interim Report Field Trial Mozambique European Commission Joint Research Centre Report EUR EN (2005) A M Lewis, T J Bloodworth, D M Guelle, F R Litttmann, A Logreco and M A Pike Systematic Test & Evaluation of Metal Detectors (STEMD) Interim Report Laboratory Tests Italy European Commission Joint Research Centre (to be published) A M Lewis Test Protocol for Dual Sensor GPR/Metal Detector Mine Detectors European Commission Joint Research Centre, January 2006 I M Dibsdall, Emerging standards for testing multisensor mine detectors In Detection and remediation technologies for mines and minelike targets X, Orlando 28 March to 1 st April 2005 Proc. SPIE Vol p J B Rhebergen and J A Ralston Test and evaluation protocols for GPR-based mine detection systems; a Proposal In Detection and remediation technologies for mines and minelike targets X, Orlando 28 March to 1 st April 2005 Proc. SPIE Vol p

27 7. Contact Details of Manufacturers and Developers CEIA SpA Costruzioni Elettroniche Industriali Automatismi Zona Ind.le Viciomaggio Arezzo - Italy Tel Fax infoumd@ceia-spa.com ERA Technology Ltd. Cleeve Road Leatherhead Surrey KT22 7SA United Kingdom Tel Fax info@era.co.uk L-3 CyTerra 10 Commerce Way Woburn, Massachusetts USA Phone: Fax: Minelab Electronics Pty Ltd PO Box 537, Torrensville Plaza SA 5031, Australia Tel Fax minelab@minelab.com.au 27

28 QinetiQ Ltd. Cody Technology Park Ively Road Farnborough Hampshire GU14 OLX United Kingdom +44 (0) Via website Shanghai Research Institute of Microwave Technology 423 Wuning Rd., Shanghai, , PR China Tel: , Fax: maxq16888@globalsources.com Tohoku University, (Prof. Motoyuki Sato) Sendai, Japan sato@cneas.tohoku.ac.jp Vallon GmbH Im Grund Eningen, Germany Tel Fax vallon@vallon.de 28

29 AIDCO-JRC Administrative Arrangement No.: MAP/2004/ Tests and Evaluation of dual sensor mine detectors based on a combination of metal detector and ground penetrating radar (TEDS) Field Tests Adam M Lewis Institute for the Protection and Security of the Citizen 6th October

30 1. Introduction Summary In the TEDS project plan it was envisaged that a comparative trial between the HSTAMIDS and ERA MINEHOUND systems would be conducted, first in the lab at Ispra then in the field at a test site of the Croatian Mine Action Centre (CROMAC). Three obstacles prevented us from realising this goal: HSTAMIDS was subject to US International Trade in Arms Regulations (ITAR) which prevents publication of test results in the open literature the contract negotiations with CROMAC were unsuccessful the purchased copy of MINEHOUND did not arrive until January JRC was able to contribute to the ITEP-endorsed field trial of MINEHOUND. Except where indicated, this report describes only that contribution. Background ERA began development of its dual-sensor system, known as MINETECT, in late It was trialed in the UK and USA and in field in Bosnia and Lebanon in 2002 and again in the US in 2003 [ref. GICHD Guide]. At this stage, the radar electronics was housed in a separate back-pack and the metal detector was a Guartel MD8. Later, the electronics package was incorporated in to the handheld unit and the metal detector was replaced with a Vallon VMH3, which is more sensitive and is able to compensate for magnetic minerals in the soil. The new version is called MINEHOUND. The UK Department for International Development (DfID), in collaboration with the German Foreign Ministry (Auswärtiges Amt), contracted ERA Technology to carry out extensive field trials of MINEHOUND in Bosnia, Cambodia and Angola, with NGO assistance from the Mines Advisory Group (MAG) in Cambodia and Angola and Norwegian Peoples Aid (NPA) in Bosnia. The entire series of trials was endorsed by ITEP as Project ITEP agreed to send specialists to the trials to observe them directly and conduct some of the tests. ITEP involvement was led by Qinetiq but included all its partners. The JRC at this time represented the European Commission on ITEP and agreed to send representatives to preparatory exercises in the UK and to the field trial in Bosnia. In this way, we were able to fulfil partly the objectives of the TEDS project. 30

31 2. Preparations Field Trial Planning A field trial of MINETECT, and two versions of MINEHOUND was conducted by Qinetiq at their test site at Hurn in the UK in December 2004, which was attended by the author. Preparatory training in use of MINEHOUND was organised by ERA at their premises at the end of June Two JRC auxiliary engineers attended this course. Fig. 1 MINEHOUND trial at Qinetiq Hurn site, December The left hand photo shows a demonstration of the handheld version to ITEP representatives. The right hand photo shows the earlier MINETECT unit, where part of the electronics has to be worn in a backpack. Field Trial Protocol ERA established a thorough test protocol for their field trial and invited ITEP collaborators to make suggestions. The following JRC suggestions were adopted: - proposals for improving the procedures for testing the deminers proposal for the ITEP invigilators to act also as operators in the blind lanes to achieve statistically valid data about the detection probability tests in which blank holes were dug and refilled, and scanned with the sensor, to investigate whether the radar responded to the disturbance of the soil. 31

32 Fig. 2 MINEHOUND Trial in Sehovici, Bosnia, September-October 2005 Left hand photo shows hillside trial site and pattern of minefields Right hand photo shows deminer carrying conventional metal detector (CEIA Mil D1) in right hand and MINEHOUND dual-sensor detector in left hand. Date of trial: Location: Sehovici, Sarajevo, BiH Manufacturer s Representatives David Daniels, Blair Graham, ERA, UK Local Organisation and Clearance Team Norwegian s People Aid BiH ITEP Invigilators Dieter Guelle JRC, Steve Bowen, Pete Blatchford, QinetiQ UK Udo Uschkerat, FGAN, Germany Execution This series of field trials was conducted in real minefields during clearance operations. When a metal indication was detected with a conventional metal detector, it was first investigated with the dual sensor and it was recorded whether or not the object appeared to be a mine, on the basis of the dual-sensor s indications. The object was then excavated and dealt with by standard procedures. The numbers of correct mine indications, false alarms and mines missed by the dual sensor, if any, were recorded. The mine clearance site at Sehovici (Fig. 2) presented a hill saddle with groups of mines laid just in front of a steep slope at around 1,100m above sea level. The mine field area in is 12,000 m². Existing war documents show that a mine barrier was laid consisting of eight groups, each of five PMA-2 or PMA-3 minimum metal anti-personnel mines. A combination of rain, mist and water from springs in the slope produced from 30 to 60% soil moisture. On some days, the moisture was high enough to prevent the GPR sensor from being used, a limitation which is well-known. 32

33 For safety reasons, the ITEP invigilators were not allowed to be present in the mined area during the clearance work. They kept records of the deminers results, performed measurements of the environmental conditions and carried out the following additional tests, not involving the deminers. Tests of the GPR s reaction to soil disturbance. Holes were drilled and refilled and the radar response monitored over successive days. This experiment was repeated with and without without compacting the ground Tests of the GPR s ability to react to mine simulants of different size, from small anti-personnel mine size to to anti-tank size. Measurements of the soil magnetic properties during the trial. For the purpose of the trial, a calibration lane was set up as well as two blind test lanes with non-live targets which were used to check that the deminers were operating at satisfactory performance levels with the MINEHOUND before they took it into the real mine field. The initial training and the first set-up of the blind lanes were done by Qinetiq and ERA staff and the lanes were thereafter looked after by the ITEP invigilators, who changed the target layout every few days to prevent the deminers remembering it. Soil samples from the Sehovici site were taken and submitted for magnetic analysis, which indicated their susceptibility and frequency dependence to be moderate [ref. Hannover]. The ERA report [Ref. Daniels] describes the conditions as heavily mineralized which is an exaggeration. Results Results of this trial and others in the series are in preparation and will be published by QinetiQ on the ITEP web site. 33

34 3. Conclusions and lessons learnt The results of this manufacturer-led trial are very promising. Significant reductions in false alarm rate were achieved without reduction in probability of detection. The acceptance of the detector by the deminer was relatively high after only a short time of use, which is encouraging. The deminers did criticise the high weight of the detector. Dual sensor technology will only be useful if deminers trust it sufficently to dismiss some of the metal detection indications as coming from innocous objects. Further experience is needed to know what are the training requirements and associated costs to achieve this level of confidence. The MINEHOUND approach requires two separate detection operations which adds to the time required to investigate an area. A possible drawback is that the extra time needed to deploy the second sensor might negate the advantage of the reduced false alarm rate. It is not possibe to evaluate this from the information so far provided. The relative merits of dual-sensor versus separate handheld metal detector and GPR should also be assessed and the time factor is important here as well. Overall, the field trials of MINEHOUND suggest that a direct, independently organized comparison with HSTAMIDS is due now, even if it was arguably premature during the life of the project. Dual-sensor is now a working and fieldable technology. Cost/benefit versus using only a metal detector is the factor that will determine whether it is adopted. 4. References [Daniels] D Daniels Minehound Trials To be submitted to J. Mine Action - R and D Section [GICHD Guide] C Bruschini, A Carruthers, H Sahli, K Koppetsch, J Glattbach and F Jaffré Guidebook on Detection Technologies and Systems for Humanitarian Demining GICHD Geneva, March 2006 ISBN [Hannover] H Preetz and J Igel Analysis of the frequency dependent complex magnetic susceptibility of soil samples from test sites in Bosnia and Herzegovina, Mozambique and Laos GGA Institute Hannover, November 2005 Private Communication to JRC 34

35 5. Contact Details of Manufacturers and Testers CEIA SpA Costruzioni Elettroniche Industriali Automatismi Zona Ind.le Viciomaggio Arezzo - Italy Tel Fax infoumd@ceia-spa.com ERA Technology Ltd. Cleeve Road Leatherhead Surrey KT22 7SA United Kingdom Tel Fax info@era.co.uk Norwegian People s Aid NPA BiH office Tel (0) /531/532/535 Fax +387-(0) info@npa-bosnia.org QinetiQ Ltd. Cody Technology Park Ively Road Farnborough Hampshire GU14 OLX United Kingdom +44 (0) Via website Vallon GmbH Im Grund Eningen, Germany Tel Fax vallon@vallon.de 35

36 European Commission EUR EN DG Joint Research Centre, Institute for the Protection and Security of the Citizen Title: Tests and Evaluation of Dual Sensor Mine Detectors based on a Combination of Metal Detector and Ground Penetrating Radar (TEDS) - Report of the Laboratory Tests Authors: A M Lewis Luxembourg: Office for Official Publications of the European Communities pp x 21.0 cm EUR - Scientific and Technical Research series; ISSN Abstract This document contains two reports from the project Tests and Evaluation of Dual Sensor Mine Detectors based on a Combination of Metal Detector and Ground Penetrating Radar (TEDS).This report describes demonstrations and basic functional tests of the HSTAMIDS, MINEHOUND, SHRIMT Model 90 and ALIS GPR/MD dual sensor mine detectors.the aim was to give an overall indication of the state of development of this class of instrument. Copies of MINEHOUND and SHRIMT Model 90 were procured for test by the JRC and measurements of the emitted radar signals were made, as well as the basic functional tests. A demonstration of HSTAMIDS AN/PSS14 was conducted for JRC by Cyterra representatives and a demonstration of ALIS by Tohoku University for JRC and ITEP representatives. All tests took place at the JRC s Ispra site in northern Italy during the period November 2003 to January 2006, on the outdoor test lane and in the laboratories.the HSTAMIDS and MINEHOUND detectors were confirmed to be fully developed products with credible performance, the HSTAMIDS being slightly more mature. The SHRIMT Model 90 is a fully developed product but with lesser performance, especially with regard to its radar. ALIS is an advanced concept with very interesting capabilities but at an earlier stage of development.the most important conclusion is that dual sensor technology has moved ahead significantly during the last three years and devices have now reached high levels of technology readiness. Dual sensor remains a leading candidate for improving efficiency, providing that the cost-benefit balance can be shown to be favourable. Further developments in productionization, ergonomics and battery-life would be conducive to the adoption of this technology. The possibility of using separate handheld MD and GPR should also be considered. The second report describes an ITEP-endorsed field trial of the MINEHOUND detector in Bosnia in 2005 to which JRC contributed. The results of this trial were encouraging and the device was well-received by the local deminers. Unfortunately, restrictions on the availability of the systems and test facilities prevented a simultaneous comparative field-trial of MINEHOUND and HSTAMIDS as had originally been planned. On the basis of the work described in these two reports, the following conclusions are drawn.systematic test and evaluation must continue to be considered a priority and is being addressed by the ITEP Multisensor Working Group. A test protocol drafted at JRC has been submitted to them. There has been concern that a premature comparative trial between HSTAMIDS and MINEHOUND could do more harm than good. However, on the evidence seen, it appears these systems are now at the point where a direct comparison would make sense. 36

37 The mission of the JRC is to provide customer-driven scientific and technical support for the conception, development, implementation and monitoring of EU policies. As a service of the European Commission, the JRC functions as a reference centre of science and technology for the Union. Close to the policy-making process, it serves the common interest of the Member States, while being independent of special interests, whether private or national. 37