The APEX PAM Float is an autonomous profiling drifter 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 continuous soundscape measurement alongside physical and biogeochemical ocean data collection. 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 already compatible 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) |
