The APEX PAM Float is an autonomous profiling float designed to combine oceanographic environmental profiling with high-resolution, broadband passive acoustic sensing. It integrates a hydrophone-based acoustic payload covering a frequency range from 20 Hz to 20 kHz, enabling soundscape measurement that can be paired with CTD and other environmental sensors, including biogeochemical options. Acoustic processing is supported through multiple gain settings (0 / 20 / 40 dB) and delivers sound pressure level outputs across 31 center frequency bins, including percentile-based metrics per band for structured acoustic analysis.
The platform is built to support real-time ocean intelligence workflows for defense-oriented and research applications, enabling wide-area monitoring through autonomous deployment. Communications options include Iridium RUDICS and encrypted Iridium SBD telemetry for remote data transmission. The system supports integration with CTD instrumentation as well as a broad suite of environmental sensors, including oxygen, optical, and biogeochemical modules, with more than 11 sensor types integrated to date for extended ocean observation missions.
| Acoustic system: | Passive broadband monitoring with integrated processing |
| Frequency range: | 20 Hz to 20 kHz |
| Hydrophone: | HTI 90 U |
| SPL data output: | 31 center frequency bins with percentile metrics |
| Gain settings: | 0 dB / 20 dB / 40 dB |
| Telemetry options: | Iridium RUDICS (APEX S 025 RRA), Iridium SBD encrypted (APEX S 026 RSA E) |
| Sensor compatibility: | CTD, oxygen, optical, biogeochemical, and additional environmental sensors (11+ types) |
