This work is the result of curiosity and interest in technology. At first, it was an accidental discovery in 2001. This led to the desire, to learn more about ELF-signals. For that, it was necessary, to develope an inexpensive and widely available receiving-technology. The result is an ELF receiver technology, which includes hardware and software. It is designed with standard parts, which are low in prices and easy to get. Any standard PC with an USB connector and a sound card can be used for detection and analysing.
My research and development was operated part-time and now covers more than 10 years. With writing of these theses in the first version, I started in October 2008.
Table of Contents
1. Introduction
1.1 Sources of low-frequency magnetic fields
1.2 Wavelengths
1.3 Magnetic field strength
1.3.1 Field around a long electrical conductor
1.3.2 Field of the magnetic dipole
1.3.3 Field strength
1.4 Example of ELF-signals
1.5 The aim of this work
2. ELF-Signal measuring technology
2.1 Hardware to acquire ELF-Signals
2.1.1 Sensors
2.1.1.1 Use of Hall-Sensors
2.1.1.2 SQUIDs (Josephson-Effekt)
2.1.1.3 Air coils
2.1.1.3.1 Inductivity of the sensor coil
2.1.1.3.2 Linearization
2.1.1.3.2.1 Linearization with an parallel resistance
2.1.1.3.2.2 Linearization with an integrator
2.1.1.4 Ground rods
2.1.2 Analog low pass filter 6th order
2.1.2.1 Types of low pass filters
2.1.2.2 Development of Butterworth-low-pass filters in general
2.1.2.3 Designing a Butterworth low-pass filter of 6th order
2.1.2.4 Measurement results
2.1.3 Concepts for digitization of the signal
2.1.3.1 Using the sound board of a personal computer
2.1.3.2 Using the USB-Interface
2.1.3.3 Digitising and preparation of the signal
2.1.3.3.1 Sampling
2.1.3.3.2 Quantization
2.1.3.3.3 Coding
2.1.3.3.4 USB-Interface
2.1.3.3.4.1 Requirements to transfer the data into the computer
2.1.3.3.4.2 The USB-Processor
2.1.4 Power supply
2.1.5 The complete device
2.1.5.1 Sensor selector, linearizer and measurement range
2.1.5.2 Filter
2.1.5.3 Power Supply, Analog-Digital-Converting and USB-Interface
2.1.5.3.1 Software for the microcontroller which works as ADC
2.2 Software for acquiring and analyzing ELF-Signals
2.2.1 Software for acquiring ELF-Signals
2.2.1.1 The ELF-Recorder
2.2.2 Software for analyzing ELF-signals
2.2.2.1 Sample rate and frequency shifting
3. Measurements in practise
3.1 Place of receiving and installation
3.2 Recording
3.3 Causality
3.4 Bearing
4. Analysis of acquired ELF-signals
4.1 ELF immission in residential areas
4.1.1 Signals with limited local spread
4.1.1.1 Whistle
4.1.1.2 Cow
4.1.1.3 Foghorn
4.1.1.4 Owl
4.1.1.5 Locomotive
4.1.1.6 Voice
4.1.1.7 Dot matrix printers
4.1.1.8 Pan flute
4.1.1.9 Key shift
4.1.1.10 Telex
4.1.2 Signals with width local spread
4.1.2.1 Goose-Signal
4.1.2.1.1 Goose - Time signal
4.1.2.1.2 Goose – Occurance and spreading
4.1.2.1.3 Summary about the Goose-signal
4.1.2.2 Heartbeat-Signal
4.1.2.2.1 Measuring of the signal parameter
4.1.2.2.2 Regional occurrences of the Heartbeat-Signal
4.1.3 Measurements in the village "Horm" (Part of Hürtgenwald)
4.2 ELF emissions outside of residential areas
4.3 Lignite mining areas as ELF-emitters
4.4 Windmills as ELF-emitters
4.5 Household appliances as ELF-emitters
4.5.1 ELF-signal of a dishwasher
4.5.2 ELF-signal of a washing machine
4.5.3 ELF-Signal of a electrical clock
4.5.4 Typical field strengths of household appliances at mains frequency
4.5.5 Consequences from the measurements with the household devices
4.6 Other signals
4.6.1 Irregular frequency curves ("squeak signal")
4.6.2 Spontaneous onset of lines
5. Artifical ELF-Signals
5.1 Estimation of the magnetic field strength (formerly flux density)
5.2 Estimation of source properties
5.2.1 Measuring setup
5.2.2 Measuring-Setup with conductor loop
5.2.3 Measurement with ground spike
5.3 Comparison with "naturally" occurring signals
6. Considerations and hypotheses regarding the signal-origin
6.1 Anthropogenic sources
6.1.1 Appliances
6.1.2 Industrial equipment / railroad
6.1.3 High frequency waves
6.2 Natural sources
7. The effect of ELF-signals
7.1 Effect of ELF-Signals in electronic circuits
7.1.1 Influence through magnetic alternating frequencies
7.1.2 Shielding
7.2 Influence of ELF-Signals in the nature
7.3 Influence of ELF-Signals on human biology
7.3.1 Hormonal balance
7.3.2 Biorhytm
7.3.3 Immune system
7.3.4 Nervous system, behavior, psyche
7.3.5 Effect models
7.3.5.1 Body current density
7.3.5.2 Calcium
7.3.5.3 Cell membrane
7.3.5.4 Cyclotron resonance model
7.3.5.5 Direct neural effects
8. Closing remarks
Objectives and Research Focus
This work aims to prove the existence of ELF signals (0 Hz < f < 25 Hz), examine their composition and structure, and investigate their origins. It addresses the research question of whether these signals are of anthropogenic or natural origin and provides a technological framework for their detection and analysis.
- Detection and verification of ELF signals below the power supply frequency.
- Development of inexpensive, standardized hardware and software for signal acquisition.
- Analysis of signal patterns and the investigation of potential sources.
- Exploration of the influence of ELF signals on electronic circuits and biological systems.
- Proposing hypotheses regarding the origins of the observed signals.
Excerpt from the Book
1.4 Example of ELF-signals
In Figure 1.6, the frequency spectrum of a recorded ELF-signal is shown as example. It was recorded at the late afternoon of the 4th March 2007, in the kitchen of the author's house in Alsdorf-Mariadorf near Aachen. The recording time was 3 hours.
On the abscissa is plotted the time. On the ordinate is the frequency. The color represents the intensity. Dark colors represents low amplitude. Red and yellow represents high amplitude.
In the chart (figure 1.6), one can see clearly a line at 16,7 Hz, which comes probably from the power-supply of the railway. In the box on the right side, structures and intermittent signals can be seen.
Summary of Chapters
1. Introduction: Introduces the frequency range and the objective of identifying and cataloging ELF signals.
2. ELF-Signal measuring technology: Describes the hardware (sensors, filters, ADC) and software developed to acquire and analyze ELF signals.
3. Measurements in practise: Discusses the methodology for receiving signals, the recording process, and techniques for bearing the signal sources.
4. Analysis of acquired ELF-signals: Provides an in-depth cataloging and analysis of various signals found in different environments.
5. Artifical ELF-Signals: Explains the generation of artificial signals to estimate intensity and waveform characteristics.
6. Considerations and hypotheses regarding the signal-origin: Examines potential anthropogenic and natural sources for the recorded ELF signals.
7. The effect of ELF-signals: Explores the impact of these signals on electronic circuits and human biology, including various effect models.
8. Closing remarks: Summarizes the findings and highlights potential future research directions.
Keywords
ELF signals, Extremely Low Frequency, magnetic field strength, sensor technology, induction, spectrum analysis, anthropogenic sources, signal acquisition, hardware, software, 16.7 Hz railway line, pulse modulation, oscillation, geomagnetic field.
Frequently Asked Questions
What is the core focus of this work?
The work focuses on the recording, analysis, and cataloging of magnetic oscillations in the Extremely Low Frequency (ELF) range, specifically between 0 Hz and 25 Hz.
What are the primary thematic areas?
The main themes include sensor technology for weak magnetic fields, signal processing and digitization, the categorization of recorded ELF signals, and the investigation of their physical origins and potential impacts.
What is the primary objective of the research?
The primary goal is to prove the existence of ELF signals within the specified range, determine their structure, and identify their sources.
Which scientific methods are utilized?
The research uses physical principles of induction, telecommunications technology for digitization, and software-based spectral analysis (FFT) to identify signal patterns.
What topics are covered in the main section?
The main section details the construction of custom ELF-receivers, the analysis of specific signals like the "Goose" or "Heartbeat" signals, and comparisons between natural and artificial sources.
Which keywords characterize the work?
Key terms include ELF signals, induction, signal analysis, anthropogenic sources, and frequency spectrum.
How is the "Goose-signal" distinguished from other signals?
The Goose-signal is characterized by a specific header followed by pulses, and it exhibits a high degree of intensity and synchronous propagation over long distances, unlike locally restricted signals.
What is the purpose of the artificial signal generation described in chapter 5?
Artificial signals were generated to calibrate and estimate the magnetic field strength of the naturally occurring signals and to better understand their waveforms in the time domain.
- Quote paper
- Franz Peter Zantis (Author), 2015, Recording and Analysis of Extremely Low Frequency Signals in our Environment, Munich, GRIN Verlag, https://www.grin.com/document/338798
