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# htmlentities() run on access: Sat 09-Sep-2023 16:34:32 +01:00. Delete this line to re-run it. # stats: $rawquot_replaced=0, $squo_replaced=0, $dquo_replaced=0, $containsBadChars=1 # format auto-updated on access: Sat 09-Sep-2023 16:34:32 +01:00 #sandbox: Journal 123 has gone to press and is due for publication in September 2023 CREG Journal 123 (0-24) This issue has a cover date of September 2023 and was published on 12th September 2023. Front Cover (1) The main river in Dan-yr-Ogof. After sufficiently heavy rainfall these cascades become impassable and the low canal beyond fills to the roof. This is close to Pot Sump where Stuart France is tracking the water level continuously, as described in his article on Page 16 of this issue. Photo: Contents (2) List of contents and masthead information. Ice Cave Photography using a Smartphone - a Hands-on Guide (3-6) , of Glacial Adventure in Iceland, provides practical guidance on how to obtain impressive photos in glacial ice caves using only a smartphone. The Ongoing Saga of the LORAN-C and eLORAN Terrestrial Navigation Systems (7-8) Despite most of the world's LF-based LORAN-C transmitters having been decommissioned some time ago, a resurgence of the technology, in the form of the enhanced eLORAN, is looking ever more likely. Since LORAN is both a source of interference to cave radios and, on the other hand, perhaps a method of underground navigation, this could be of interest to cavers. reports. Letters to the Editor (8) HF Underground - WormAnt, Building Blocks (9) Implementing a touchscreen solution for your next project, by . NSS Communications and Electronics Section Meeting 2023 (10-11) The National Speleological Society annual convention provided the venue for the customary meeting of the Communications and Electronics Section. reports on a well-attended and interesting meeting. Reciprocity in Cave Radio Antennas (12-14) Reciprocity is a property of passive electrical networks and electromagnetic fields. It is sometimes loosely cited as being why a radio antenna can be used interchangeably as a transmitter or receiver; but what does that actually mean? demonstrates that although cave radio antennas obey reciprocity laws, we have to be careful what we mean by reciprocity. We Hear (15) Roundup of news and events: brings us the latest to impact the world of cave radio and electronics. Cave Exploration with Bouncing Robots, Muon Technology: Navigation by Cosmic Rays, Malaysian Smartphone Cave Photography. Cave River Level Telemetry at Dan-yr-Ogof (16-20) describes a system that combines two telephone technologies to measure and transmit regular cave river water level readings over a long, fixed single-wire telephone cable to surface data logging equipment and subsequently to the cloud. Field Equations in Conducting Media (20) When studying the fields from a small dipole antenna (electric or magnetic) in a conducting medium, it is sometimes helpful to use complete field expressions rather than the simpler quasi-static approximations. It is not always easy to find these in a textbook, so has set them out here, as a useful reference. The Cave Surveying Group's Spring 2023 Meet-up (21) provides the low-down on the Cave Surveying Group's latest get-together in the Yorkshire Dales. As well as discussing some of the latest technology for regular surveying and the acquisition of 3D scans, attendees were able to see some of this gear in operation, and witness the impressive results obtained. Turning 3D Models into Cave Maps (22-24) 3D scanning technology promises to fulfil the dream of creating accurate computer models of caves. has experimented with the use lidar sensors in recent iPhone models, as reported in (Arkko, 2021). While the scanning itself still has many challenges, there is also a more fundamental question: what is it that one can do with a 3D model? In this article, Jari describes his experiences of using the models to produce plan-view and cross-section maps.