ULFLOG  ...  ( the data collection module ... see ...  ref #1 ).
1) user-friendly,  reliable and able to automatically re-start 
   after a power outage. 
2) runs on any standard  IBM compatible computer ... EGA/VGA color 
   monitor  preferred 
3) data viewing : live, delayed and summarized month-to-date
4) process and save data with a logical, automated file-naming system.
5) user selection of any, or all data channels.
6) user selection of how much data will be saved  ...  including both 
   the amount of signal-processing and user-adjustable and intelligent 
   amplitude-thresholds
7) data  format that is readable by standard spread-sheet  programs
8) companion viewing modules to view and analyze the collected data..
9) automated system log-file ... with optional user inputs about unusual 
   activities
10)automated collection and processing of transient events
11)remote, live telephone access.

Software will be posted on my ftp site as requested.

ULF VIEW  ...  ( the viewing module ).
1) views raw ULFLOG data
2) fourier analysis of raw data.


ULF PLOT ... ( the monthly summary viewing module).
1) displays the monthly digital data summaries
2) displays the impulse files
3) places solar and lunar positions on display


ELOPE  ... ( the statistical analysis package ).
1) full access to historic events ... (www data sources)
2) analysis ... one fault at a time.
3) correlation to non USGS data


The basic data-sampling-rate is 120 Hz.  Adjacent sampling pairs are 
added to achieve an effective sampling rate of 60 Hz. 60 Hz was chosen 
to eliminate 'aliasing'  between the sampling rate and the 60 Hz power 
line frequency and to produce a response function that minimizes 
sensitivity to power-line pickup, which is a common problem in ULF 
sensing systems.

ULFLOG  uses a  "non-standard" (ref #4) digital-filtering algorithm that 
might be called decimation  by  octaves" (DBO).  This algorithm resolves 
input  data into nine octave bands, including  0.1 to 0.2, 0.2 to 0.4, 
0.4 to 0.8 Hz  etc). It has several advantages over the traditional Fast 
Fourier Transform (FFT), specifically::

1) it does not suffer from the severe windowing problems inherent in the 
FFT.  Windowing requires that signals near the beginning and end of the 
block be reduced to zero, while signals at the center of the block are 
artificially enlarged.  Thus, some significant transients may be 
entirely missed in an FFT.

2) The low frequency limits of an FFT algorithm are determined by the 
size of the block analyzed.  DBO extends the analysis to arbitrarily 
long  times and low frequencies without consuming huge amounts of  RAM 
or placing a serious burden on the processor.

3) DBO provides optimal time resolution for each octave.  With  the FFT, 
the time resolution at all frequencies is determined by the lowest 
data-acquisition frequency.  With DBO, transient response to high 
frequencies is not dragged down by the need to process low frequency 
data.

4) DBO uses less memory and is much faster.

A disadvantage of the DBO algorithm is that it cannot support non-octave 
data processing.  Because this is a well known and desirable feature, 
the  FFT is included as part of ULFVIEW.
Several types of antennas have been tried. The best consists of a 3 foot 
permalloy-core,  rod antenna.  An alternative is to use a bundle of 
construction steel with a copper winding.  
Air core antennas are not used.





We want to offer these programs as our  ...  SHAREWARE ...contribution 
to the ULF precursor study.  We suggest a shareware fee of $99 for the 
set of  three  programs. All software,  users manuals and hardware descriptions
 are available ... by FTP ... from 
this site.  Hard copy manuals are also available.  

For insurance reasons we cannot sell any hardware..

(1) ULFLOG,  ULFVIEW and ULFPLOT are copyright protected programs.
       Commercial use of the share-ware version is prohibited.
       Contact : Ben Parks 
                 2381 Wild Goose Canyon Road
                 Placerville,  Calif. 95667.
                 (530)-626-8889 ... or baparks@jps.net

(4) the Filter Algorithm is described in the ULFLOG users manual.