Feasibility Study of Space to Underwater Optical Communications ScyLight - Optical Communication Technologies

  • Status
    Ongoing
  • Status date
    2025-04-22
  • Activity Code
    7C.096
Objectives

The aim of this programme is to investigate the feasibility of high data rate communications from satellite to autonomous underwater vehicles (AUVs) via laser communication. This requirement is in response to the increasing number of AUV and underwater devices being deployed and the requirement for greater capacity information transfer underwater.

Currently available underwater communications via acoustic and RF technologies are suited to long range, low data rate and short-range, high data rate respectively. Additionally, both acoustic and RF technologies do not offer communication channels through the air-water interface. By exploring the opportunities offered by optical communications technology there is potential for long range, high data rate communications through the air-water interface, exploiting to the relatively low attenuation of blue-green light through both the atmosphere and water.

Challenges

The key challenge of the project is overcoming the technical challenges posed by the environment through which the optical link must pass. Water is a highly scattering medium that cannot be avoided in this scenario, a significant amount of signal loss and dispersion will occur through water and must be overcome.

Challenges are also posed by the size, weight and power constraints that will be imposed on a system due to the constraints of both AUVs and satellites.
 

Benefits

AUVs are being increasingly used by commercial, military and scientific sectors, their ability to operate autonomously allows access to extreme environments that were previously inaccessible with manned and remote-controlled vehicles The concept of space to underwater laser communications offers an opportunity to enable communication with AUVs while maintaining their autonomous nature. Laser communications can transmit through the air water interface removing the need for either support vessels or for an AUV to surface to have access to communications when submerged.

Features

The components and technologies required to achieve a space to underwater optical communications link will be explored throughout the project.

System Architecture

The project outcome is a technology readiness level 2 (TRL2) baseline technical solution for achieving space to underwater communications using laser communications. This solution will include the following:

  • Combined impact of the underwater and atmospheric channel behaviours,

  • Technologies including lasers and detectors,

  • Link budget, aperture sizes and power levels,

  • System scenarios and,

  • Waveform and modulation formats.

Recommendations for future development of the solution will be generated based on the identified limitations with the aim to process the technology to higher TRL in the future.

Plan

The feasibility study runs between March 2025 and November 2025, during which four main technical areas will be explored:

  1. Identification AUV use cases and review of current communication methods,

  2. Generation of technical requirements for space to underwater communications

  3. Feasibility study and trade off analysis of potential technical solutions

  4. Evaluation of identified technical solutions

Two key milestones will occur during the feasibility study, the first is scheduled for June 2025 and will occur when technical areas 1 and 2 of the feasibility study are complete. The second milestone will occur upon the completion of the entire study.

Current status

The project is progressing well with the team finalising the first of the four main technical areas. Four uses cases for space to underwater communications on AUVs and the scenarios within which they would operate have been identified, these are:

  • Long Range Oceanographic Surveys,

  • Subsea Infrastructure Monitoring,

  • Mine Counter Measures and,

  • Maritime Search and Rescue Operations.

Additionally, a review of current communication methods employed by AUVs, and state of the art communication technologies has been conducted. Next steps include establishing a set of technical requirements and exploring their feasibility.

Prime Contractor