This Open Research Institute (ORI) projects meetup on July 15, 2025, covers progress and plans across several key initiatives. The main focus is the Opulent Voice digital mode, with updates on modem development, including resolving issues with PI controllers and exploring advanced Forward Error Correction codes. Significant progress has been made on the Python-based human radio interface, with a major bug fix (COBS) and a new goal of implementing audio functionality in the web UI before broader user testing. Another major topic is the Earth-Venus-Earth (EVE) radar project, discussing bandwidth considerations (technical vs. regulatory) and plans for a test using a moon bounce. The meeting also includes updates on a photogrammetry project to analyze the surface of the DSES radio dish and a detailed report on recent FCC regulatory activities, including ORI's involvement with the Technological Advisory Council (TAC) and ARRL's push for an omnibus update to amateur radio rules.
ORI Project Updates: Opulent Voice, EVE Radar, and Regulatory Efforts
0:02:07 EVE Radar Project & Bandwidth: Thomas provides an update on the Earth-Venus-Earth (EVE) project, noting an upcoming moon radar experiment to test concepts. A key discussion point is signal bandwidth, considering the practical limits of equipment at partner sites (like DSES), regulatory restrictions for high-power transmissions, and the technical definition of the signal (spread spectrum vs. very slow frequency hopping).
0:07:27 Opulent Voice Modem Development: Matthew, rejoining the project, plans to revisit the modem's differential encoder/decoder and address any remaining issues. Future work includes adding lock detectors, improving diagnostics, and deciding on a final Forward Error Correction (FEC) scheme, with modern options like spinal codes, LDPC, and polar codes being considered to improve on the current baseline.
0:15:15 PI Controller Analysis: The team is working on a technical article for QEX magazine explaining the modem's two Costas loops (PI controllers). A discrepancy exists between the theoretical numbers in the article and the stable numbers used in the code. A collaborator, Pete, suggests the issue may stem from interactions between different clock domains.
0:18:41 Human Radio Interface Progress: The Python-based user interface for Opulent Voice has seen significant progress. A major bug related to Constant Overhead Byte Stuffing (COBS) for framing data has been solved. The next critical step is to get audio working in the web interface, which currently supports text chat and configuration.
0:20:45 User Testing and Accessibility Goals: Once audio is functional, the team plans to solicit user feedback on the software, first on a local network and later over the internet. The core design philosophy emphasizes accessibility, with goals to provide multiple ways to access information, such as audio playback of past transmissions and a future feature for live transcription.
0:26:26 Photogrammetry for Dish Analysis: Ed Frezma is making progress on a project to use photogrammetry to create a 3D mesh of the DSES radio dish surface. This will allow for an accurate RMS surface variability measurement to help diagnose a discrepancy in the antenna's expected performance. Ed is currently testing the workflow by creating a 3D model of his car using ping pong balls as markers.
0:30:29 FCC Regulatory Update: The FCC's Technological Advisory Council (TAC) is nearing the end of its charter, with ORI having contributed to recommendations on dynamic spectrum sharing. Separately, following an FCC call to "delete" obsolete rules, the ARRL is advocating for a comprehensive "omnibus" update to amateur radio rules, including the removal of remaining symbol rate limits. ORI plans to coordinate with ARRL to support these efforts.