sandbox: Journal 135 has gone to press and is due for publication in September 2026
CREG Journal 135 (0-24)
This issue has a cover date of September 2026 and was published on 1 September 2026.

Front Cover (1)
Carol Lawrence taking photos with a smartphone in Gaping Gill, Yorkshire. Photo: <span class="author">Dave Ryall</span>

Contents (2)
List of contents and masthead information.

News and Notes (2)
Style Guide and Submissions Guidelines, CREG Field Meeting, Hidden Earth 2026, Editorial Team.

CREG Field Meeting: Spring 2026, Derbyshire (3-4)
CREG held its recent field meeting in Castleton in the Peak District national park. <span class="author">Mike Bedford</span> reports on the demonstrations and presentations.

Wearable Mobile Mapping System for Cave Surveying - Part 2 (5-7)
Previously, <span class="author">Janusz Be&#807;dkowski</span>, <span class="author">Micha&lstrok; Pe&lstrok;ka</span> and <span class="author">Tomasz Paw&lstrok;owski</span> introduced the MANDEYE-MR - a lidar-based wearable mobile mapping system for cave surveying composed of two rigidly assembled 3D lidars. Here, they illustrate the benefits offered by this device by presenting the results of a surveying exercise in a Polish cave.

Real-time Data Analysis from Cave Sensors - Part 1 (8-12)
<span class="author">Luca Tringali</span>, <span class="author">Alexander Debenjak</span>, <span class="author">Tecla Tripari</span>, <span class="author">Caterina Bearzotti</span> and <span class="author">Giacomo Canciani</span>, of Gruppo Speleologico Talpe del Carso - J.K. Kra&scaron;ki Krti, describe the data storage and analysis tools that have been adopted for their open-source real-time cave dataloggers with telemetry. An SQLite database is used to store data, and SQL queries are used to run different statistics to understand data reliability and trends&colon; daily average, linear regression and correlation coefficients. The procedures and queries described here are generic enough to be easily adapted to any other data source.

PIXIE: A Low-cost Open-source In-situ Fluorometer - Part 1 (13-16)
<span class="author">David Eason</span> introduces the open-source PIXIE project&semi; a lower-cost open-source in situ submersible fluorometer. PIXIE provides four independent channels to detect multiple fluorescing agents in water flow paths near-simultaneously. Such an instrument provides a semi-professional tool for carrying out hydrographical, high-resolution flow-path mapping and analysis.

Interference Cancellation - Some Analogue Techniques from the Last Century (17-19)
Although we might be expected to desire to use digital signal processing in any new radio design, there might still be something to learn by studying older analogue processing techniques developed in the 1970s and 1980s. A number of these were described in the magazine Wireless World and the original articles are still available online. <span class="author">David Gibson</span> reviews some of the techniques, one of which is distinctly novel.

John Rabson (20)
Former editor and long-time contributor to the CREG Journal, John Rabson died recently. <span class="author">Rob Gill</span> looks back at some aspects of John's life.

Mobile Phones for Underground Photography (21-24)
Several serious cave photographers remain committed to dedicated cameras, most probably a DSLR. But, as <span class="author">Dave Ryall</span> reveals, dramatic results can be obtained using a smartphone. Here, he provides a beginner's guide to smartphone cave photography.