The group has a NUMIS Poly MRS instrument from Iris Instruments for surface MRS. The NUMIS Poly is a four channel MRS-instrument. Typically we record the MRS signal in a coincident loop configuration, while the three other channels are used to simultaneous acquisition of the EM-noise characteristics in the surroundings (remote reference technique). Sophisticated filtering techniques using the remote references have been developed within HGG improving the signal to noise/ratio significantly.
A magnetometer is needed to determine the Larmor frequency and for recording of fluctuations in the earth's magnetic field during recording of a full MR-sounding, which can take 5-10 hours. Furthermore the MRS-sounding is followed up by a WalkTEM-sounding, to obtain the resistivity model. The resistivity structure is important to include in the modeling of the MRS signal.
Mobilization of the MRS-instrument is relatively time-consuming and we therefore often use our EM-noise collector instrument to scout the survey area for suitable MRS-locations before deploying the full MRS system.
MRS-system, NUMIS Poly