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# format auto-updated on access: Fri 25-Feb-2022 21:14:53 +00:00

# sandbox: Journal 117 has gone to press and is due for mailing to subscribers by 5 March 2022
CREG Journal 117 (0-24)
This issue has a cover date of March 2022 and was published on 1 March 2022. 

 

Please note: The paper version of issue 118 incorrectly refers readers here for the appendix to the article The Circle of Least Confusion. For that item, see journal 118.

 

Please note: Pages 1 and 24 form a stereo pair, which can only be viewed correctly if p24 is on your screen to the left of p1. To achieve that, the article on p22 can be downloaded by itself and has p24 and p1 in the correct sequence. Front Cover (1) Examples of Poster-Sized Stereo Pairs. Photos: Daniel Chailloux, Michael Perryman. For download see article on page 22. Contents (2) List of contents and masthead information. News and Notes (2) Spring 2022 Field Meeting, Rob Gill. Robocrane: Supporting Lunar Lava Tube Robotic Explorers (3-5) Exploration of lunar lava tubes is a challenging task. One of the main problems that exploring robots will face is the lack of solar light to charge their batteries, and the lack of a direct line-of-sight to establish a communication link. As Manuel Arias, Fermín Navarro and Fernando Aguado Agelet report, Robocrane is a system that tackles both challenges by deploying a charger and a communication relay inside the pit through a skylight. The crane is also capable of deploying the exploring robots inside the pit, simplifying their design. We Hear (6) Roundup of news and events: Mike Bedford brings us the latest to impact the world of cave radio and electronics. A Dentist's Approach to Caving Projects?, Introducing the Thrunite TH30, The Internet of Underground Things. Photographic Enhancement of Cave Paintings using DStretch (7-10) Jon Harman introduces DStretch, his tool for enhancing photos of rock art using the technique of decorrelation stretch. He illustrates its use with examples of cave paintings from Baja California which show impressive results. Building Blocks (11) The noble art of soldering, by Tony Haigh. BuecherNet at Fort Stanton Cave, New Mexico (12-15) A network of wireless data transceivers is being established to transmit water and air sensor data from the Snowy River passage in Fort Stanton Cave to the surface. Lithium thionyl chloride batteries were selected for long life, though these introduced further challenges. John T. M. Lyles describes the technology, the production build and the current state of implementation. Applications of Chain Codes for Position Encoders (16-18) 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. An online demonstration program accompanies this article at bcra.org.uk/cregj/more/j117 Cyclic Binaries / Chain codes – Demo for CREGJ 117 (webpage) This online demonstration program by David Gibson accompanies the above article. Modifying the DH18DSL Hammer Drill for Ease-of-use in the Cave Environment (19-21) By modifying it to accept modular external batteries while retaining the ability to use the original batteries, and delivering a load-bearing, power-carrying connector, several caving benefits are on offer for this popular hammer drill. Alexander Ried provides a practical guide which also applies to several other drills. Letter to the Editor (21) Underground 'Radio' Powered by Compressed Air, David Gibson Viewing Poster-Sized Stereo Pairs (22-24,1) 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. Examples are shown on the covers of this Journal and in the online file bcra.org.uk/cregj/more/j117/3d.html.

 

Please note: i) The final page of this article is the front cover, page 1. ii) To view the stereo pair on p24 and p1 correctly online, you must instruct your browser's PDF plug-in to display the pages in 'two-page view'. How to do this will depend on your browser and, if it is not obvious how to achieve that, try looking for a menu icon (☰).