The technique and procedure described here can be performed with any model of Landmapper (older models ERM-01 and -02 or new ERM-03 and -04). 
Manual VES” cable set made to measure 16 layers of topsoil down to approximately 9 m. The worksheets for pre-set electrode spacings in such cable re-calculating measured resistivities to apparent resistivity, see this Google Drive public folder for downloads: 1D-VES.
We developed and tested with LandMapper a 60m-long cable, measuring down to ~ 20 m for one custom hydrology project.
This manual VES technique is most convenient to use with three people. Follow step-by-step instructions and video below.
- On your site establish the center location for the VES profile. It is a center point between M2 and N2 in the diagram above. Here the person with LandMapper will stay and conduct measurements.
- Send two persons outward in a straight line from the center to unwind both red wires from the probe up to 14 m mark (last electrode) and insert electrodes in soil => A1 and B1.
- Measuring person grounds central black M1N1 electrodes at MN/2=1.0 m (green label, black wires). Connect black wires (MN) to MN- terminals of LandMapper.
- Connect red wires (AB) to AB- terminals of LandMapper.
- Take ER-reading at K0=1 and AB electrodes at 14 m.
- Move A and B electrodes to 12 m marks at both sides – take ER-reading.
- Continue until AB/2=6.0 m.
- Move MN electrodes to 0.5 m marks (black wire, green label) and AB to 5.0 m mark.
- Continue taken measurements until last AB/2=1.0 m. It is also the previous location of M1N1 electrodes for steps 3-7.
- Field ER-readings can be stored in LandMapper memory or recorded manually.
- The recorded ER-values need to be multiplied on appropriate K-coefficients. Use tables below or input in Excel file to carry out auto-calculations.
Field data recording table. You can print this table from the website or download Manual 1D VES workbook Excel files there is a table already pre-formatted to fit on the Landscape page.
| AB | MN | The measurement from deep to shallow | |||||||
| distances, m | m | # | AB/2, m | K-set | K-taken | ER-1 | ER-2 | ER-3 | ER-4 |
| [A1B1] = 28 | 2.0 | 1 | 14.0 | K0=1 | 1 | 10.41 | |||
| [A2B2] = 24 | 2.0 | 2 | 12.0 | K0=1 | 1 | 27.47 | |||
| [A3B3] = 20 | 2.0 | 3 | 10.0 | K0=1 | 1 | 102.8 | |||
| [A4B4] = 18 | 2.0 | 4 | 9.0 | K0=1 | 1 | 15.75 | |||
| [A5B5] = 16 | 2.0 | 5 | 8.0 | K0=1 | 1 | 13.49 | |||
| [A6B6] = 14 | 2.0 | 6 | 7.0 | K0=1 | 1 | 10.26 | |||
| [A7B7] = 12 | 2.0 | 7 | 6.0 | K0=1 | 1 | 21.28 | |||
| [A8B8] = 10 | 1.0 | 8 | 5.0 | K0=1 | 1 | 30.07 | |||
| [A9B9] = 9 | 1.0 | 9 | 4.5 | K0=1 | 1 | 12.29 | |||
| [A10B10] = 8 | 1.0 | 10 | 4.0 | K0=1 | 1 | 13.73 | |||
| [A11B11] = 7 | 1.0 | 11 | 3.5 | K0=1 | 1 | 15.37 | |||
| [A12B12] = 6 | 1.0 | 12 | 3.0 | K0=1 | 1 | 62.18 | |||
| [A13B13] = 5 | 1.0 | 13 | 2.5 | K0=1 | 1 | 16.02 | |||
| [A14B14] = 4 | 1.0 | 14 | 2.0 | K0=1 | 1 | 26.04 | |||
| [A15B15] = 3 | 1.0 | 15 | 1.5 | K0=1 | 1 | 18.18 | |||
| [A16B16] = 2 | 1.0 | 16 | 1.0 | K0=1 | 1 | 18.18 | |||
Instead of writing ER values on the paper in the provided table, you can store ER in LandMapper’s memory. You still need to keep track of what cell # starts new VES profile and which K values had you used (those K1-K9 are stored indefinitely, but don’t change K in the middle of field trip).
Recalculation table. This table automatically recalculates field ER measurements taken in the table above (in Excel file). Here on website it just shows values of K-geometric coefficient (K-multiply) for pre-set distances among electrodes using formulas for Schlumberger and Wenner arrays.
| AB | MN | Measurement from deep to shallow | Recalculate ER for VES interpretation | |||
| distances, m | m | # | AB/2, m | K-multiply | K-taken | ER-1 |
| [A1B1] = 28 | 2.0 | 1 | 14.0 | 306.3 | 1 | 3188.6 |
| [A2B2] = 24 | 2.0 | 2 | 12.0 | 224.6 | 1 | 6170.4 |
| [A3B3] = 20 | 2.0 | 3 | 10.0 | 155.5 | 1 | 15986 |
| [A4B4] = 18 | 2.0 | 4 | 9.0 | 125.7 | 1 | 1979.2 |
| [A5B5] = 16 | 2.0 | 5 | 8.0 | 99.0 | 1 | 1335 |
| [A6B6] = 14 | 2.0 | 6 | 7.0 | 75.4 | 1 | 773.59 |
| [A7B7] = 12 | 2.0 | 7 | 6.0 | 55.0 | 1 | 1169.9 |
| [A8B8] = 10 | 1.0 | 8 | 5.0 | 77.8 | 1 | 2338.1 |
| [A9B9] = 9 | 1.0 | 9 | 4.5 | 62.8 | 1 | 772.21 |
| [A10B10] = 8 | 1.0 | 10 | 4.0 | 49.5 | 1 | 679.36 |
| [A11B11] = 7 | 1.0 | 11 | 3.5 | 37.7 | 1 | 579.44 |
| [A12B12] = 6 | 1.0 | 12 | 3.0 | 27.5 | 1 | 1709.3 |
| [A13B13] = 5 | 1.0 | 13 | 2.5 | 18.8 | 1 | 301.97 |
| [A14B14] = 4 | 1.0 | 14 | 2.0 | 11.8 | 1 | 306.78 |
| [A15B15] = 3 | 1.0 | 15 | 1.5 | 6.3 | 1 | 114.23 |
| [A16B16] = 2 | 1.0 | 16 | 1.0 | 2.4 | 1 | 42.836 |
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