To: ammon, koper@eas.slu.edu
Subject: GSAC

Well time to start making presentations - Beijing tomorrow

I am finally un jetlagged - and GSAC is slowly moving forward

The Butterworth filtering works - there was a nice trick in sac that
got me going into the right direction - actually derived an alternative
method that did not use complex numbers (Hey I am using C and not C++)

I believe that I have the worst behind me - i just got CHANGEHEADER working
So to be able to do what I normally use SAC for I need to implement

PLOTRECORDSECTION - this will be interesting
        PRS will do it -- I will figure out limits later
        If we look at receiver functions with the ray parameter set
                in USER4, then
        PRS USER4   will plot trace(time) vs ray parameter, or
        PRS AZ  will plot traces vs AZIMUTH (always handy for RFTN's
                The only question for PRS is how to present the time series
                We could have time to right and distance or USER 4 down,

                Perhaps we should borrow an option form GHOSTVIEW
                PORTRAIT LANDSCAPE SEA-SCAPE UPSIDE-DOWN
                I see the need for the following for the default plot
                of traces vs distance


                X-axis          Y-axis
                Distance        Time increaing up
                Distance        Time increasing down (reflection profiles)
                Time            Ray parameter increasing down

                I know how to do this, but what to call this


-------------
At present I am happy with time series with equally spaced DT.
I do not see a need for a general plot of xy and especially not xyz

I also implemented the FFT internally so that the time series is
not overwritten so that
        p1
        fft
        psp
        p1
is possible withouot a reread

I may only implement a WRITESP AM or WRITESP PH so that I will nto have to suppo
rt SAC complex spectra files.


