A summary of EMFlow v3.2 processing options used to produce CDIs for the WTRMP data is given below. It is expected that this information will be of use to experienced EMFlow users only. The processing options follow guidelines for frequency domain data specified in the "EMFlow Advanced Users Manual" (Macnae, 2001). Note that the Hummingbird data sign convention changed between 1999 (when the Dundas survey was flown) and 2001-02, when the remainder of the data was acquired. Horizontal coplanar and vertical coaxial data channels are all defined as positive in the Pasminco_Dundas dataset, whereas vertical coaxial data is negative in the Balfour, MRV, Dolcoath and Meredith datasets. Appropriate EMFlow frequency scaling factors for the five datasets are given below. Frequency scaling factors (Balfour, Mount Read Volcanics, Dolcoath, Meredith) 880 Hz: 1 985 Hz: -4 6600 Hz: 1 7000 Hz: -4 34k Hz: 2 Frequency scaling factors (Dundas) 385 Hz: 1 985 Hz: 4 6600 Hz: 1 7000 Hz: 4 34k Hz: 2 Important EMFlow settings at the various stages of the EMFlow process are listed below: CREATE BASIS FUNCTION ------ ----- -------- Primary field stripping OFF Approximation type: EXPONENTIAL Tau selection number of TAUs: 20 TAU min(mSec): 2.80e-004 TAU max(mSec): 3.00e-001 ASCII TO BINARY ----- -- ------ Smoothing OFF DECONVOLUTION ------------- Fitting parameters: Primary field inclusion ON Fit Tau PLS all taus Smoothing =0.4 Threshold (norm): 1e-004 Normalisation: By global maximum (the original raw data file from the contractor was reformatted so that lowest frequency data was recorded first) Error weighting: 880 Hz in-phase has been deweighted due to presence of widespread levelling problems. 34 kHz quadrature data deweighted due to breakdown of quasi-static approximation at high frequency. Weights 880 990 6600 7000 34kHz inphase 0.1 0.1 0.3 0.1 0.3 quadrature 1 0.3 1 0.3 0.1 CDI --- time cutoff: 1 max depth (m) 230 Force conductors to surface: true Allow short TAUs correction: Cut: false Predict: true