NSGG UXO Test Site
As part of the 2013 Near Surface Geophysical Group (NSGG) field exhibition, on geophysical techniques for detecting and interpreting Unexploded Ordinance (UXO), a 20m2 area of the NSGG test site was seeded with 16 commonly encountered geophysical targets. 5 of the targets were inert UXO targets (which were removed after the field exhibition and replaced with objects with equivalent properties). All other targets were chosen to offer a verity of geophysical responses which wouldn’t be detected by all of the typical geophysical instruments used for locating UXO targets (generally Magnetometers/Gradiometers, Transient Electromagnetic and Ground Penetrating Radar) but would be detected by at least one of the techniques.
On the 18th of May 2013 an initial survey was conducted over the seeded area with a G-858 caesium gradiometer, Mala X3M ground Penetrating Radar system and an EM61MK2 time domain metal detector.
These data sets formulate the master datasets which delineate the signature of each targets buried. Plots of the Master data sets are can be seen by following the subsequent links, Electromagnetic, Ground Penetrating Radar and Magnetics.
The positioning of each target relative to its neighbours was carefully considered in order that each anomaly could be fully resolved when following the standardised data acquisition procedures for each technique. A tabulated description of each target along with its relative position (expressed in the local coordinate system established at the NSGG test site), size and depth of burial are outlined below.
| Table1 : Positioning of Objects within TS2 Sub Area 5 | ||||||||
|---|---|---|---|---|---|---|---|---|
| # | Square | Easting | Northing | Easting | Northing | Depth (m) to top of feature | Depth (m) to bottom of feature | Object Description |
| 1 | A | 42.5 | 37.5 | 41.6 | 37.6 | 0.3 | 0.31 | Magnet |
| 2 | B | 47.5 | 37.5 | 46.85 | 38 | 0.13 | 0.33 | Sandstone Rock (0.35×0.35×0.20m) |
| 3 | C | 52.5 | 37.5 | 51.95 | 37.75 | 0.23 | 0.28 | 1.5” projectile (solid Iron) |
| 4 | D | 57.5 | 37.5 | 57.3 | 37 | 0.22 | 0.23 | Horizontal Steel Plate (0.15×0.15×0.01m) |
| 5 | E | 42.5 | 32.5 | 43.1 | 33.3 | 0.15 | 0.3 | Air filled void (0.32×0.25×0.15m) |
| 6 | F | 47.5 | 32.5 | 47.5 | 32.05 | 0.03 | 0.4 | 25 lb bomb |
| 7 | G | 52.5 | 32.5 | 52.15 | 32.1 | 0.15 | 0.3 | Vertical Steel Plate (0.15×0.15×0.01m) |
| 8 | H | 57.5 | 32.5 | 57.95 | 32.9 | 0.3 | 0.45 | Water fill void (0.25×0.2×0.15m) |
| 9 | I | 42.5 | 27.5 | 41.8 | 28.15 | 0.15 | 0.3 | 6” projectile (solid Iron) |
| 10 | J | 47.5 | 27.5 | 48.05 | 26.95 | 0.3 | 0.3 | Five pit |
| 11 | K | 52.5 | 27.5 | 52.5 | 28.1 | 0.05 | 0.05 | Selection of 8 coins |
| 12 | L | 57.5 | 27.5 | 57.1 | 27.7 | 0.2 | 0.2 | Horizontal Aluminium plate (0.24×0.20×0.005m) |
| 13 | M | 42.5 | 22.5 | 42.4 | 21.85 | 0.1 | 0.15 | Smoke bomb 2” |
| 14 | N | 47.5 | 22.5 | 47.5 | 22.75 | 0.1 | 0.28 | Vertical Aluminium plate (0.3×0.18×0.003m) |
| 15 | O | 52.5 | 22.5 | 52.1 | 21.9 | 0.2 | 0.28 | 3” Projectile (solid Iron) |
| 16 | P | 57.5 | 22.5 | 57.8 | 22.1 | 0.25 | 0.33 | Bricks ×10 laid flat |
Since the seeded area was established in May 2013 the data archive has developed considerably and now incorporates 10 different datasets encompassing 4 different geophysical techniques and 8 different manufactures equipment.
As of the 10th of July 2013 all UXO targets were removed and replaced with targets of equivalent material properties. Subsequently additional data acquisition was undertaken to assess the signatures of the new targets. At present this data has not been processed but it is hoped that this data will find its way onto the website in due course.
| Table2 : Replacement UXO Targets TS2 Sub Area 5 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| # | Square | Easting | Northing | Easting | Northing | Depth (m) to top of feature | Depth (m) to bottom of feature | Original Object | Replacement Object |
| 3 | C | 52.5 | 37.5 | 51.95 | 37.75 | 0.15 | 0.22 | 1.5” projectile (solid Iron) | 2 × Scaffold brackets 0.06DIA ×0.15m(0.5Kg) |
| 6 | F | 47.5 | 32.5 | 47.5 | 32.05 | 0.15 | 0.39 | 25 lb bomb | Casserole pot 0.2mDIA x0.1m (1Kg) |
| 9 | I | 42.5 | 27.5 | 41.8 | 28.15 | 0.1 | 0.25 | 6” projectile (solid Iron) | Oxy Acetylene canister 0.52mDIA x 0.17m 13.9Kg |
| 13 | M | 42.5 | 22.5 | 42.4 | 21.85 | 0.1 | 0.15 | Smoke bomb 2” | Spray Can 0.07mDIA×0.15m 0.125Kg |
| 15 | O | 52.5 | 22.5 | 52.1 | 21.9 | 0.18 | 0.25 | 3” Projectile (solid Iron) | Aerosol canister 0.07mDIA x0.26m 0.25Kg |
Further Information
For further information on the NSGG test site please refer to the www.nsgg.org.uk.
The archived datasets for this resource are held by Geomatrix Earth Science. For access to these resources please contact sale@geomatrix.co.uk.