From: "Larry Cochrane" <cochrane@..............> Subject: New WinSDR release and wish list Date: Sun, 17 Feb 2002 15:57:49 -0800
Hi everyone,
I have a new WinSDR release available on my web site. You can download from
this page http://www.seismicnet.com/winsdr/. Here's what's new with WinSDR
version 2.0;
I added the ability to digitally filter the income data from the A/D board
that is supplied to the alarm/event triggering process. You can have WinSDR
apply a lowpass and / or highpass Butterworth filter to the data similar to
the digital filtering within WinQuake. In the Alarm Settings dialog box you
will see a group box "Digital Filter". There you can enable or disable the
lowpass and highpass filtering, set the cutoff frequency and the number of
poles for each channel. The number of poles controls the steepness, or how
quickly, the filter attenuates the data above (lowpass) or below (highpass)
the cutoff frequency. You can view the filtered data going to the event
triggering process by selecting the View / Display Filtered Data menu items.
Currently the filtering is only applied to the data used for event detection
and the data displayed in the real-time window, if the Display Filtered Data
mode is turned on. The data saved too disk in the daily record files is not
filtered, so PSN event files, and the data displayed in the replay window
and GIF images, is not filtered. The next release will allow you to filter
the replay data and GIF images but not the raw data saved to the disk. I
think this should remain unfiltered since applying the filtering does
distort the data a little.
You can see how a lowpass filter can filter out the local ground noise here
http://www.seismicnet.com/WinSDR/filter.gif. This images shows the first 4
1/2 minutes with the Display Filtered Data mode turned on and the last 5
min. with it turned off. The data is from a 1 Hz vertical geophone and the
filter was set to a 2 Hz 6 pole lowpass filter. As you can see, applying a
lowpass filter really helps remove the local ground noise.
This release also fixes several bug found by the beta testers and the Visual
C++ debugger. The debugger found a few memory leaks and some other problems
mostly related to the GIF saving process.
As usual, please let me know if you run into any problems with the new
release. Given the bugs I found using the debugger everyone should upgrade
to the new release as soon as possible.
Wish List;
If you have any features you would like to see in WinSDR please let me know.
If it's not to difficult I will try and add it to the next release. Please
send your wish list to the winsdr list so others can comment on your
suggestions.
-Larry
.
