EPIRB Telemetry: Encoded Beacon Maritime Distress Signals by The Knotzept Research Institute

Abstract
This album is a high-fidelity sonic simulation of maritime EPIRB (Emergency Position-Indicating Radio Beacon) data transmissions, employing radiofrequency synthesis and analog modular processing. By leveraging advanced techniques such as ring modulation, frequency shifting, and phase encoding, the album reconstructs the spectral and temporal characteristics of EPIRB bursts in the 406 MHz COSPAS-SARSAT band. The result is a precise auditory representation of digital distress signals, modulated and transmitted under simulated satellite reception conditions. Additionally, the transmission incorporates encryption methods used to secure distress data, simulating the real-world protection of sensitive information transmitted during emergencies. The encryption processes mirror the cryptographic algorithms used to safeguard the integrity of beacon signals, preventing unauthorized tampering. This secure transmission is then processed by global control centers, which monitor the status of EPIRB beacons and assist in emergency response.

Signal Generation and Modulation Techniques

1.1 Carrier Synthesis and Pulse Emission
Low-frequency precision oscillators (LFOs) replicate the EPIRB duty cycle (50s to 25s burst interval).
Subharmonic carrier synthesis ensures spectral stability akin to real SAR transmitter emissions.
Controlled noise shaping simulates atmospheric absorption and Doppler shift variations.

1.2 Modulation Architecture

Ring Modulation (RM): Employed to generate nonlinear harmonic components that resemble binary phase shift keying (BPSK) waveforms, used in beacon data encoding.
Frequency Shifting (FS): Dynamic spectral transposition models real-world frequency deviations observed in LEOSAR/MEOSAR processing.
Biphase-L Keying (BPSK Simulation): Approximate emulation of Manchester-encoded distress data packets.
Transmission Environment Simulation

2.1 Propagation Model
High-Q bandpass filtering mimics satellite ground segment receiver selectivity.
Multipath interference synthesis recreates transmission distortions due to ionospheric dispersion and tropospheric scattering.
Simulated thermal noise floor variations align with real-world signal attenuation patterns.

2.2 Spectral Processing and Interference Modeling
Narrowband frequency oscillation simulates natural EPIRB frequency drift within ±2 kHz, induced by oscillator instability.
Short-time delay feedback processing approximates the echo characteristics of satellite retransmission.
Aliasing artifacts and spectral alias removal mimic MEOSAR processing errors under high noise conditions.

Structural Design and Temporal Composition

3.1 Temporal Burst Arrangement
Each track is a self-contained transmission burst, mimicking serialized beacon activations.
Time-domain variations correspond to different EPIRB encoding protocols (Standard Location Protocol vs. Serialized Location Protocol).
Micropulse reverb and phase inversion processing enhance the perception of distress signal harmonics.

3.2 Data Encapsulation in Sound Design
Tracks follow an intentional spectral and amplitude patterning, mirroring the beacon activation sequence in a search-and-rescue scenario.
Intermittent noise gating represents real-world beacon self-test and activation diagnostics.
Filtered pulse transients replicate real-time signal acquisition by SAR satellites.

Encryption and Control Centers

4.1 Signal Encryption
Real-world EPIRB signals are protected by encryption to prevent interception and ensure the integrity of the transmitted data. The album emulates the cryptographic processes used, incorporating encryption schemes that secure the beacon’s distress message. This process includes the application of key-based cryptography to encode location data, ensuring that only authorized stations can decipher and respond to the distress signal.

4.2 Control Center Simulation
After the signal is transmitted, it is received and decoded by regional control centers, such as those in the COSPAS-SARSAT network. These centers monitor the status of EPIRB beacons and direct search-and-rescue efforts by interpreting encrypted messages. In this simulation, the encoded data is passed through a virtual control center, emulating the analysis of real-time distress signals by emergency response teams. The control centers’ role is critical in verifying the authenticity of the transmission and coordinating the appropriate response.


Conclusion
This album serves as both an artistic interpretation and a technical exploration of EPIRB signal behavior in emergency scenarios. By translating raw radiofrequency transmission data into an auditory medium, it offers an immersive experience that reflects the spectral, temporal, and structural properties of actual SAR distress signals. Through precise modulation techniques, analog processing methodologies, and the inclusion of encryption and control center simulations, it bridges the gap between electromagnetic telemetry, cryptography, and experimental sound design.

Institutional unit dedicated to the advanced exploration of frequencies, synthesis, and arrangement techniques, driving innovation in electronic sound. Combining classic and cutting-edge technology, it develops new approaches to frequency manipulation, spectral processing, and sound design, pushing the boundaries of sonic experimentation.

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