In a previous article, was asking to the MacCommunity to create a technical software to use in the VLF/ULF research (please see: MAC-SOFTWARE FOR VLF/UL article in

A Master in this field research, Michael Mideke, did answer back immediately, proposing his point of view. Anyone involved in the field is kindly requested to propose his ideas about this software project.


Article: UMGI

Author: Michael Mideke


I like your ideas. UMGI (Universal Mac Geophysics Instrument) makes perfect sense. But how to get there from here? The design problems involved are all very far beyond my knowledge and ability, yet if this tool existed I could learn to use it and I would use it. As you suggest, I can list functions that I believe would be useful and also bring up other ideas that might be helpful in moving toward implementation.

Your proposal for an instrument responding to pre-set noise (or signal) thresholds could be usefully expanded, not only to take samples of a specific duration at selected intervals (which I think you have described) but also to trigger recording when selected types of signals appear - a whistler detector for instance could initiate recording for perhaps 2 minutes, resetting with each new whistler.

Another valuable feature would allow recording and analysis of the amplitude and phase characteristics of one or more manmade VLF signals for detection of SIDS and Trimpi events.

I would also suggest the inclusion of some sort of sferic counter. Every sferic is a lightning stroke and lightning activity seems closely keyed to global climate factors...

I saw real time sonogram/spectrograms at Stanford, on a big slow phosphor screen - years ago. No doubt a modern Mac could do the same job and more and this would be a wonderful educational, analytical and artistic tool.

As mentioned below, the software should be able to integrate data from multiple sources, subtracting random local noise.

Ideally we should be able to plug anything into the UMGI- a solar ultraviolet sensor, an earth current pickup, VHF meteor scatter receiver, cosmic ray detector, ionospheric sounder, rhyometer.... Which is to say that however many dedicated inputs may be designed in there also should be available channels that the user can tailor to his or her interest of the moment without having to be either an electrical engineer or a software designer. The Mac environment already demonstrates this potential - it is only a question of developing desired applications.

As noted under "Standard Instruments," UGMI should incorporate calibration tools and routines for each feature requiring the use of external hardware.

The manmade noise question -

Perhaps the first application for the instrument we are imagining should be to make detailed and systematic analysis of many actual urban residential radio noise environments at VLF -ULF frequencies. Adaptive comb filters can only deal with the actual powergrid signals, while in addition we have all kinds of devices whose radiation is broad, unstable and not necessarily in phase with the power grid- arcs and sparks, SCRs...and vehicles. So important questions are: What does the noise environment really look like and how far can the best filtration go in reducing it? The few reports I have heard suggest that adaptive comb filters work pretty well when confronted by a single rural powerline with not too many things running on it, not so good when surrounded by lines and power users. I'm sure good information exists. Ev Paschal and Mike Dorman have both designed filters reputed to be effective.

Moving down to the ELF -ULF range I believe we're forced to magnetic sensors and thus subject to magnetic interference - magnetic fields from motors, moving vehicles, any ferrous metal in motion. Also mechanical vibration - anything that moves the sensor in the geomagnetic field.

John Lauerman must have a practical understanding of those problems by now.

An ultimate solution to VLF-ULF noise already at hand?

Given an UMGI network generating universally compatible simultaneous data, localized random noise can simply be subtracted in software by comparing the data from two or more stations and dropping everything not heard by each or all. This assumes that some of the desired data can be recorded along with the noise at each or most stations. If the recording stations are not too far apart the data should still provide a good picture of "local" conditions. The ability to perform this operation would be an extremely valuable feature of the software.

The development process -

Begin with a wish list. What features would people already involved in this field as amateurs or professional researchers like to see embodied in the Universal Instrument?

Use the wish list as a guide to search out information. Which of the desired features already exist in a form that can be directly utilized? Which exist in the PC environment? Which exist as functional devices or programs which might be modified or improved to suit our needs?

Then design can begin. You need some very smart and knowledgeable people in the areas of software design and data processing. What are the minimum specifications of a computer capable of supporting the desired functions. If it turns out to be a G-4 are we still interested? Hopefully what happens is that a very useful tool is developed which works even with older laptops and simply works faster and does more things better on more powerful machines. Great emphasis should be given to creating a system which can evolve in parallel with computer developments.


Michael Mideke