Further information

Personal Homepage

This page last updated on 19-Jun-2023

Special offer to CSM Students: Im offering a special deal to CSM students. You can subscribe to the online version of the CREG journal (see samples) for free (normally £4) and you can subscribe to the printed edition – four quarterly issues – for £5 (normally £16). To take up this offer, please contact me.  (If your message to my Exeter address bounces, please see the information here). Additionally, for the offer to be valid, you must give an email address at exeter.ac.uk and, for the printed version, you should have a delivery postcode that begins with TR. Offer expires at the end of 2023.

No other content here yet, but you can visit my external web site at at http://site2.caves.org.uk/mcrosolv/

Research

This page last updated on 19-Jun-2023

This page lists my current research projects at the Camborne School of Mines, as well as earlier projects that I undertook at the Mines Rescue Service, and some of my personal research interests.

Scroll down for...

• Current Projects
• Earlier Projects

My Research Interests

In addition to the projects I am funded for at the moment – see Current Projects – I have a number of other personal research interests, as listed below. Notes on these topics might be added in due course (this note dated 27-Oct-2022).

• Radio antennas using high-permittivity ceramic tiles
• The use of a torus (or anapole) as a radio antenna
• Algorithms for creating conjugate gear profiles
• Ferro-electric materials for small power generators (energy harvesting)
• Virtual machines and threaded interpreters (microprocessor and compiler design)
• Properties of binary sequences (inverse sequences, single-channel Gray codes)
• Data-logging and monitoring in caves (especially as part of climate-change models - see External Activities)
• Chemical reactions between starches and sugars
• Construction of a portable time spinner ('procrastinator') and a symbol reader (An out-of-hours project - see my steampunk essay )

I also have an interest in collecting examples of "hoaxes" in physics. That is, people who disbelieve Maxwell, Einstein or Hawking, and who promote their unsubstantiated ideas counter to the principle of quod supplantandum, prius bene sciendum. I have half a dozen on my list now. Further reading: see Mateus Araújo's blog Crackpots in my Inbox

Recent Projects

INDIRES Newsletter 1 INDIRES Newsletter 2 INDIRES Newsletter 3

RFCS INDIRES Project: Information Driven Incident Response (INDIRES) Funding: RFCS Grant Agreement 748632 Grant recipient: consortium of industrial and academic partners including Camborne School of Mines Completion: June 2020 Website: indires.eu Principal team members at CSM: Mike Bedford, Prof Pat Foster, Dr David Gibson, Dr Declan Vogt Project objectives: to enable critical information to be gathered during a serious mining incident, without reliance on a mine's fixed power or communication network; and to aid personnel rescue and mine safety My main involvement: to investigate resilient forms of through-rock radio data communication using novel antenna structures and mesh networks Outcomes: Notes to be added in due course. (This note dated 4-Sept-2019) RFCS STAMS Project: Long-term stability assessment and monitoring of flooded shafts (STAMS) Funding: RFCR-CT-2015-00001 Grant recipient: consortium of industrial and academic partners, including Camborne School of Mines Completion: June 2018 Website: stams-rfcs.eu Principal team members at CSM: Mike Bedford, Prof John Coggan, Dr David Gibson, Project objectives: to develop multifunctional monitoring and inspection modules, and to design permanently installed sensors, to guarantee periodic and long-term continuous monitoring of flooded mine shafts. My main involvement: to assess the feasability of building an inductively-coupled array of sensors to function in low-cost underwater pressure-proof enclosures. Outcomes: Simple Enclosure is Waterproof to 400 Metres. Further notes to be added in due course. (This note dated 4-Sept-2019)

Earlier Projects

From 2003 to 2012 I was a Research Project Manager at the UK's Mines Rescue Service (MRSL). This table lists the research projects undertaken by MRSL and my involvement. Final Reports for all the RFCS-funded projects are available as free downloads from the European Commission's Europa Bookshop - just type the ISBN into the search box.

Project	Full Title	My contrib.	Me as listed author?	Contract	Publishing year and ISBN
PR-133	Extending the utility of underground data transmission networks and other data processing equipment	★★★	??	ECSC 7220 PR-133	2005?
UPTUN	Upgrading of existing Tunnels (UPTUN); Workpackage 3 Human response; Deliverable 3.3; Human Factors Aspects in Tunnels: Tunnel User Behaviour and Tunnel Operators	★★★	??	EU FP5 G1RD-CT-2002-766	2006?
EPCWCMS	Enhancing the performance of mine communication, warning and condition monitoring systems	★★★		RFCR-CT-2003-00003	2008	978-92-79-08172-9
WATERCHEM	Optimisation of mine water discharge by monitoring and modelling of geochemical processes and development of measures to protect aquifers and active mining areas from mine water contamination	★★		RFCR-CT-2003-00006	2008	978-92-79-08777-6
SAFETECH	Optimisation of surveillance, technical equipment and procedures to prevent workers from danger attributed to fire, hazardous or toxic gases, firedamp or climatic conditions	★		RFCR-CT-2003-00010	2008	978-92-79-08717-2
IAMTECH	Increasing the efficiency of roadway drivages through the application of advanced information, automation and maintenance technologies	★★	✔	RFCR-CT-2004-00001	2009	978-92-79-11704-6
ADEMA	Advances in exploration methods and applications	★★★	✔	RFCR-CT-2005-00001	2010	978-92-79-14549-0
RAINOW	Researching the applications of open innovative wireless technologies	★		RFCR-CT-2005-00003	2010	978-92-79-14145-4
NEMAEQ	New mechanisation and automation of longwall and drivage equipment			RFCR-CT-2006-00001	2011	978-92-79-21598-8
MINTOS	Improving Mining Transport Reliability			RFCR-CT-2007-00002	2012	978-92-79-22247-4
ADRIS	Advanced Drivage and Road-Heading Intelligent Systems	★★★	✔	RFCR-CT-2007-00002	2012	978-92-79-22226-9
MINFIREX	Minimising risk for and reducing impact of fire and explosion hazards in underground coal mining			RFCR-CT-2007-00003	2012	978-92-79-22247-4
PRESIDENCE	Prediction and Monitoring of Subsidence Hazards above Coal Mines	★★		RFCR-CT-2007-00004	2012	978-92-79-22246-7
EDAFFIC	Early detection and fighting of fires in belt conveyor			RFCR-CT-2008-00002	2013	978-92-79-25117-7
EMTECH	Mine Emergency Support Technologies	★★★	✔	RFCR-CT-2008-00003	2013	978-92-79-29320-7
EMIMSAR	Enhanced Miner-Information Interaction to Improve Maintenance and Safety with Augmented Reality Technologies and New Sensors	★★★	✔	RFCR-CT-2009-00002	2013	978-92-79-33083-4
LOWCARB	Low carbon mine site energy initiatives			RFCR-CT-2010-00004	2014	978-92-79-40328-6
MISSTER	Mine shafts : improving security and new tools for the evaluation of risks	★		RFCR-CT-2010-00014	2015	978-92-79-45342-7
COGASOUT	Development of novel technologies for predicting and combating gas outbursts and uncontrolled emissions in thick seam coal mining	★		RFCR-CT-2010-00002	2015	978-92-79-43619-2

 

External Activities

This page last updated on 19-Jun-2023

Scroll down for ResearchGate, CREG journal, BCRA Trustee, Hidden Earth, Awards and Prizes.

ResearchGate

I have a user profile at ResearchGate that includes contributions to ResearchGate's questions and answers section.

CREG Journal

The Cave Radio and Electronics Group is a Special Interest Group of the British Cave Research Association. I have been involved with it almost since its inception in 1998. I have held posts as the Group's journal editor, technical editor and treasurer. I am also (alongside my CSM colleague Mike Bedford) one of its principal authors, with around 300 contributions to the journal.

• A small selection of my contributions are listed in the Publications list of my staff profile.
• To see a full list of my CREG articles, you can use my CREG Journal search engine.
• In 1993 I won an award for my work as the editor of the CREG journal - see Awards/Prizes below.

Photo: The photo  (above or opposite, as your web browser dictates) shows Gareth Kennedy, a former lecturer at CSM, setting up wifi equipment in a disused railway tunnel at Ashbourne, in Derbyshire, to perform experiments that were part of the RFCS RAINOW project. (Photo by David Gibson).

Trustee of the British Cave Research Association

I have been closely involved with the British Cave Research Association, a UK charity, since about 1990. I have held several posts, including its research-fund administrator. From 2010 to 2022 I was the honorary secretary. I am still a trustee of the Association.

I also maintain BCRA's web site and supervise its publications operations. This extends to writing code for the sales operations on the web site, editing and laying out some of its publications and organising their printing.

From 2003 to 2013 I supervised the production of the journal Speleology, and I was the editor of many of the issues.

At the moment (20220) I am involved with BCRA's project to set up a Cave Science Centre at Poole's Cavern in Derbyshire, as part of the team providing loggers and Internet connectivity. The web site, still under development (March 2022) is at cave-science.org.uk. 

The facility is being designed to encourage undergraduates to undertake projects relating to cave science, climate and environment. The rationale is that undergraduates are sometimes disscouraged by universities from entering caves. Even with the promise of nationally-qualified cave 'minders', students have sometimes been unable to get permission to go underground in 'wild caves' to perform experiments and to undertake research as part of their degree dissertations. Some articles about the Cave Science Centre have appeared in the CREG Journal  (Search for "Cave Monitoring Centre", because the facility was initially known as that).  Also see my article Building Rugged Equipment for Use in Caves, at bcra.org.uk/cregj/?j=109

Cave research is important for several reasons – limestone aquifers are an important resource for a large part of the world’s population, and so tracing water flow (and water pollution) is important. Caves also provide a historical climate record, in speleothems, that is important in environmental research into climate change.

 

Hidden Earth

Each year, BCRA runs a national conference known as Hidden Earth. I am part of the organising team for that event.

Recently, we have experimented with a network of computers that provide timetable displays, as well as news and information. The latest iteration uses a Raspberry Pi computer at the heart of each ‘information point’, which operates a web browser, pulling information from a local web server. Read my notes on this project by searching the CREG journal for Hidden Earth Timetable Display

Awards and Prizes

I have never won anything significant, and certainly not in my professional life. The closest I can get is two of the national caving awards, administered by BCRA.

• 1996: Giles Barker Award for cave photography, for my design of a Flashgun Slave Unit  that was subsequently used by many cavers around the world.
• 1993: Tratman Award for speleological literature, for the CREG Journal.

It was some time ago now, but I also have...

• 1972: National Cycling Proficiency Certificate
• 1969: Quarter Mile Swimming Certificate

I dont think I was ever a blackboard monitor.

Recent Publications

This page lists some of my more recent publications. Unfortunately, I cannot add them to the university's list because an honorary appointment does not confer access to Symplectic. So, here are some recent notes from the CREG journal. Click on the "CREGJ" links to go to the CREG Journal web site.

Page last updated on 19-Jun-2023

Comparing Loop and Line Antennas for Cave Radio Applications – 1, CREGJ 122, pp14-16. June 2023

An induction-loop transmitter can operate at a higher current than a grounded electric dipole because the loop has a relatively low resistance when compared to the resistance between two earthed electrodes. However, the magnetic field from a loop falls off more rapidly with distance, so it is not straightforward to say that one antenna is better than the other. Several other factors, both physical and practical, come into play. In this article, David Gibson outlines how we might go about making a comparison. This is a nonmathematical article – a more complete treatment will be given in part 2 of this article.

Current Problems in Cave Radio, CREGJ 121, pp11. March 2023

Although through-rock radio is now well established, there are a number of puzzles that David Gibson asserts would benefit from further study.

The Circle of Least Confusion, CREGJ 118, pp16-17 + appendix. June 2022

David Gibson describes a term in optics and photography that is used to derive the range of distances – the depth of field – over which a subject remains in good focus. This does not, of itself, require restating here, although there are some circumstances, such as the construction of stereoscopic and stacked-focus images, where a recap is useful. Additionally, there is a modification to the standard formula that extends its use to small-format digital cameras.

Applications of Chain Codes for Position Encoders, CREGJ 117, pp16-18 + online demo. March 2022

Linear and rotary position encoders can measure position using a single-track binary sequence known as a chain code. In a follow-up to his article in CREGJ 116, David Gibson gives some further explanation of how chain codes can be used.

Underground 'Radio' Powered by Compressed Air, (Letter to the Editor), CREGJ 117, p21. March 2022

Viewing Poster-Sized Stereo Pairs, CREGJ 117, p22-24&1. March 2022
(also see update in CREGJ 119, p20)

Stereoscopic pairs are traditionally viewed using a handheld 3D viewer. But when printed in a magazine or shown on a display board, such images are difficult to view unaided, as well as being necessarily very small because the centrelines of the images must match that of the eye. For stereo pairs to have an impact, they must be larger, but a traditional method of viewing larger images requires them to be printed in false colours, thus making them impossible to appreciate without special tinted glasses. In this article, David Gibson describes a simple technique that avoids this problem and allows poster-sized full-colour photos to be viewed without any artificial aid. Significantly, this allows them to be fully-appreciated both as flat images and as stereo pairs.

Position Encoder Uses Single-Track Gray Code: Part 1, CREGJ 116, p22-24. December 2021
(also see part 2 in CREGJ 118, pp19-22, and further update in CREGJ 119, pp19)

There are many examples, in electronic equipment design, where it is necessary to measure linear or rotary position, which is often achieved using an optical or magnetic encoder. Simple encoders detect only changes in relative position; multi-track encoders can measure absolute position but, as David Gibson explains, a single-track encoder can, under the right conditions, also encode absolute position.

A Simple Class-D Single-Sideband Modulator, CREGJ 115, p10-13. September 2021
(also see part 2 in CREGJ 116, p20-21. December 2021)

David Gibson describes how the output pulses from two class-D double-sideband modulators using carrier-frequency PWM (CF-PWM) can be interleaved to create a class-D single-sideband modulation. The method, assumed to be novel, is simple enough to be implemented on a standard micro-controller, which means that it is more accessible to hobbyist designers than a DSP implementation.

Data Protocol and Coding Examples for the British Cave Science Centre, CREGJ 115, p16-20. September 2021

The British Cave Science Centre (BCSC) at Poole's Cavern in Derbyshire has been fitted with sensors and data loggers in support of a number of cave science projects. The sensors transmit their data to the Internet via a broadband telephone connection. Two data protocols are used, essentially a 'push' and a 'pull' operation, which David Gibson describes as 'Source-As-Browser' and 'Source-As-Server'. Each method has its advantages and disadvantages, which are explained in this article, that also gives examples of the code needed to handle the operations.

Update: Energy Harvesting, CREGJ 114, p10. June 2021

Further notes on energy harvesting and human-powered lighting by David Gibson.

The SSB Paradigm for Cave Radio is Outmoded - Is it Time to Move On?, CREGJ 114, p12-14. June 2021

If you want to build a cave radio that extends the art and doesnt just repeat earlier work, then David Gibson argues that SSB techniques are outmoded. Not only is DSB modulation simpler, but it offers additional opportunities - including receiving SSB signals, if that is still required. Expressly, Gibson suggests that trying to implement traditional analogue SSB methods on a DSP platform is without merit, because tailored DSP techniques (such as the CORDIC used in Graham Naylor's Système Nicola) will perform so much better.  

Cave Radio antennas, CREGJ 114, p19. June 2021

In another of our 'Fundamentals' series, David Gibson explains why we use induction loops and grounded electrodes as cave radio antennas.

Update: (1) Battery Polarity Protector, (2) Pressurised Enclosures, CREGJ 113, p12. March 2021

(1) Further to his notes on building rugged equipment, David Gibson describes a simple addition to a battery connector that prevents cells being inserted in reverse. (2) As a follow-up to his notes on building rugged equipment, David Gibson further describes the use of a pressurised enclosure to prevent moisture ingress.

Energy Harvesting with Electrets, CREGJ 113, p16. March 2021

David Gibson envisages a portable energy-harvesting device utilising a wristwatch-style automatic winder, with the mainspring driving an electrical power generator that uses an electret material. The mainspring provides a method of regulating the power transfer, not unlike the concept of 'power matching'.

Update: Regenerative Brake, CREGJ 112, p21. December 2020

In an extension of his notes on regenerative braking, David Gibson describes how to build an LED lamp that is powered by a falling weight.

The Parallel-Fed Voltage Multiplier, CREGJ 111, pp10-12,22. September 2020

Voltage doublers and the Cockcroft-Walton voltage multiplier are examples of devices that use capacitors as charge-pumps to generate a high voltage at a low power in a relatively simple circuit. The conventional voltage multiplier is series-fed, acting as a 'bucket brigade' to pass the charge from one element to the next. This is difficult to analyse, as well as being inefficient, with a law of diminishing returns applying. A better scheme is the less well-known parallel-fed device, which has several advantages. David Gibson analyses this device, arguing that it deserves to be better known, and suggests some possible cave electronics applications.

The Mystery of the Missing Energy, CREGJ 111, pp20-22. September 2020 

Whenever a capacitor is charged, energy seems to go missing. This has consequences when designing equipment that makes use of capacitor charging, such as a charge pump. David Gibson explains the phenomenon and challenges the reader to say where the supposedly missing energy might have gone.

Regenerative Brake Charges Your Caving Lamp Whilst You Abseil, CREGJ 110, pp13-16. June 2020    

A caver abseiling down a pitch will lose potential energy, which is converted into heat in his abseiling device; but what if it were converted into useable energy instead? David Gibson explains the principles behind regenerative braking and how you might use the braking energy to charge a battery. However, this is for theoretical interest only, and definitely not something to try out in practice!  

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