Seismic Toolkit 0.69a

Filtering the data: all filters are causal recursive IFR (Infinite Impulse Response) written using the bilinear Z-transform in the time domain. Their conception using a few number of coefficients gives them very fast with a low memory cost.

The adaptation factor of frequency warrants no deformation in the frequency domain of the transfer function. The main filters used are the following: Butterworth High-Pass and Low-Pass (n order), Farrer 10s-6s Low-Pass (a combination of rejector and Low-Pass specially designed for removing oceanic noise), Integrator, Derivator, Integrator with cut-off frequency, Derivator with cut-off frequency, Trend removing, Rejector (n-order), Envelop with Hilbert (not recursive at all), compensator of (n-order), Polynomial filter (n-order, not recursive at all ).

Major Functions:

1. Data plotting : channel by channel, all channels, zoom, unzoom, unfilter, instantaneous time and amplitude information with mouse pointer.
2. Fourier domain: Power Spectral Density (PSD) in linear-linear, log-log axes; independent windows for each channel, instantaneous frequency and amplitude information with mouse pointer, zoom, unzoom of spectra. Dirac, Hilbert transform, Time-Frequency representation (tested until 1 million of points per channel on 3 channels.
3. Polarization : easy and fast particule motion representation in both horizontal plane and incidence plane, with automatic computation of best direction with eigen vectors of the covariance matrix. Display of linearity and planearity coefficient.
   

Enhancements:

• New package (.deb) for Debian - Ubuntu
• New package (.dmg) for MAC OSX 10.4 (Tiger)
• Add function Derivator _Fc (a derivator with a cutting frequency
• Impose : setlocale(LC_ALL,"C") to avoid regional setting as decimal separator;