> SLS-PROPRIETARY // NO EXTERNAL RELEASE

# Tidefall — SLS-305 (Program ALDER)

**Public name:** Tidefall  **Tracking #:** SLS-305  **Codename:** ALDER
**Category:** Autonomy & C2  **Fiscal Year:** FY2025
**Contract award:** 17 April 2025

## Summary

Tidefall is the fleet command-and-control suite — the layer above CEDAR that
turns individual vehicles into a coordinated force. ALDER tasks heterogeneous
USV/UUV groups, fuses their sensor feeds into a common maritime picture, and lets
one operator supervise many platforms. Where CEDAR drives a single hull, ALDER
conducts the orchestra.

## Notional Capabilities

- Multi-vehicle tasking and deconfliction across surface and subsea assets
- Sensor fusion of ESM, ISAR/radar, AIS, EO/IR, and passive acoustic tracks
- Single-operator supervisory control with exception-based human-on-the-loop
- Contested-comms operation: opportunistic mesh, store-and-forward tasking
- Plays directly with HERON, ORCA, SALMON, ROCKFISH and all SLS payloads

## Program References

- "Multi-Sensor Data Fusion to Enhance Maritime Situational Awareness," *Proc.
  IEEE*, 2023.
  [IEEE 10282392](https://ieeexplore.ieee.org/document/10282392/)
- Salish Littoral Systems, *ALDER: Supervisory Command and Control for
  Heterogeneous Maritime Autonomous Fleets*, SLS Technical Report TR-305, 2025.
- "Multi-sensor data fusion in maritime surveillance: a review on methods and
  applications," *PeerJ Computer Science*, 2026.
  [peerj.com/articles/cs-3765](https://peerj.com/articles/cs-3765)
- SLS C2 Group, *Multi-Sensor Track Fusion for Common Maritime Pictures*,
  SLS White Paper WP-TIDEFALL-02, 2025.

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