N221-023 TITLE: Miniaturized Sonobuoy High-Data-Rate Tether

OUSD (R&E) MODERNIZATION PRIORITY: Autonomy

TECHNOLOGY AREA(S): Air Platforms

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop innovative miniaturized data tether deployment modules for use in a variety of sonobuoys for antisubmarine warfare (ASW).

DESCRIPTION: NATO A-size buoys have been produced in large quantities over many decades. The standardization of the A-size bare buoy form factor has supported a tremendous economy of scale to reduce unit production costs and has driven designs of compatible platform launchers and stores management, as well as logistics support. The advent of new sonobuoys requiring improved sensors requires miniaturization of components in the sonobuoys to allow for more space for sensor arrays. Additionally, deep and long-life sonobuoys have unique size and capacity constraints due to additional tether length and/or larger power supplies. With advances in miniaturization technologies, the Navy seeks new and innovative data tether deployment modules for use in multiple sonobuoys.

This SBIR topic addresses the need for new data tether modules to provide a strengthened, full-duplex communications datalink between the surface unit and the suspended payload. Following air launch and water entry, the data tether deploys the payload to a programmed depth and then suspends the payload for the duration of operations. The data tether module functionality includes: (a) the upper and lower mechanical, data, and power interfaces with the sonobuoy surface and payload units; (b) tether deployment; (c) full-duplex communications; (d) suspension of payload unit static and dynamic loads while providing for requisite acoustic isolation; and (e) packaging as an extractable sonobuoy module. Power for any interface electronics would come from either or both the surface and payload units.

The performance objectives address two miniaturized data tether deployment modules.

Module #1 Performance Objectives:

• deployed tether length threshold: a fixed, to-be-specified length ranging from 1,000 ft�12,000 ft (304.8 m�3,687.6 m); objective: command selectable with up to four to-be-specified lengths ranging from 1,000 ft�16,000 ft (304.8- m�4,876.8 m)
• static tensile load threshold: 5 lb (2. 27 kg); objective: 10 lb (4. 54 kg)
• full-duplex data rate threshold: up to 100 kb/s; objective: up to 1. 5 Gb/s
• diameter: threshold < 4.5 in. (11.43 cm)
• cylindrical stack height: threshold 8 in. (20.32 cm); objective 6 in. (15.24 cm)
• power consumption threshold: < 1. 5 W; objective: < 0. 5 W
• operational life threshold: 14 days; objective 180 days
• ability to be ruggedized and packaged to withstand the shock, vibration, pressure, temperature, humidity, electrical power conditions, etc., encountered in a system built for long-term, nonclimate- controlled storage, and for airborne use
• reliably deployed in sea-state conditions 0 through 5 (international scale) with 90% two-dimensional current profile meantime between equipment failure threshold: 90 days; objective: 180 days
• full-rate production cost: threshold < $1,000; objective < $500 (based on 1000 units)

Module #2 Performance Objectives:

• deployed tether length threshold: a fixed, to-be-specified length ranging from 90 ft�1,500 ft (27.43 m�457.2 m); objective: command selectable with up to four to-be-specified lengths ranging from 90 ft�1,500 ft (27.43 m�457.2 m)
• static tensile load threshold: 4 lb (1.81 kg); objective: 8 lb (3.63 kg)
• full-duplex data rate threshold: up to 100 kb/s; objective: up to 1. 5 Gb/s
• diameter: threshold < 3.5 in. (8.89 cm); objective: < 4.5 in. (11.43 cm)
• cylindrical stack height: threshold < 2 in. (5.08 cm); objective < 1.5 in. (3.81 cm)
• power consumption threshold: < 1.5 W; objective: < 0.5 W
• operational life threshold: 6 hr; objective 8 hr
• ability to be ruggedized and packaged to withstand the shock, vibration, pressure, temperature, humidity, electrical power conditions, etc., encountered in a system built for long-term nonclimate- controlled storage, and for airborne use
• reliably deployed in sea-state conditions 0 through 5 (international scale) with 90% two-dimensional current profile meantime between equipment failure threshold: 4 hr; objective: 8 hr
• full-rate production cost: threshold < $500; objective < $250 (based on 1,000 units)

Technology Innovation will include a sonobuoy high-data-rate tether deployment module that meets the performance objects and metrics below. Currently, there does not exist a small diameter fiber optic tether capable of supporting a deep sonobuoy deployment. Fiber optics have reduced volume per foot compared to existing sonobuoy tethers that will enable the development of a deep sonobuoy high-data-rate deployment module. In addition, fiber optics support a significantly higher data rate from the deep sensor to the surface. Successful sonobuoy high-data-tether deployment module development will result in a deep sonobuoy capability. Specific technology innovation is a small high-data-rate fiber deployment module with a high-strength member supporting deep depth. Details of this innovation include, but are not limited to:

1. High strength tether that is > 3 mi long and has the ability to support the weight of sensors at the bottom of the tether for up to six months.
2. High-strength tether diameter must be small enough to fit into the fiber-optic deployment module with a size of 4.5 in. (11.43 cm) in diameter and 6 in. (15.24 cm) in height. This further complicates the ability of the tether meeting the high strength necessary for a deep-deployed sonobuoy.
3. The tether needs to double as the communication link from depth to the surface. The use of fiber optics as the tether results in transmission of acoustic detection using a high-digital-data rate from depth to the surface that is required by this topic. Copper wire is not capable of providing the high-data rates required.
4. Module #2 requires a much smaller high-data-rate fiber-optic deployment module. This is due to the limited space in future tactical sonobuoys as a result of increased sensor space requirements, and for use in miniature sonobuoys (mBuoys). Miniature sonobuoys provide aircraft the capability to carry twice as many sonobuoys. Module #2 has the same innovations and challenges described in 1-3 above, but with a greatly reduced depth. The remaining innovations ? (a) small module, (b) high strength tether, and (c) small-diameter fiber optic ? are the same as above.

PHASE I: Develop, design, and demonstrate the feasibility of a viable and robust miniaturized data tether deployment module solutions consisting of a tether deployment canister packaged with the requisite length of tether and interface electronics, as required to pass uplink and downlink communications, to receive power from the upper and lower sonobuoy components, and with a compliant suspension, to isolate a notional acoustic payload from surface dynamics. Identify technological and reliability challenges of the design approach and propose viable risk mitigation strategies. The Phase I effort will include prototype plans to be developed under Phase II.

PHASE II: Design, fabricate, and deliver miniaturized data tether deployment module prototypes based on the design from Phase I. Test and fully characterize the system prototype. The interface electronics to the sonobuoy upper and lower units need not meet the miniature packaging requirements to allow use of discrete assemblies, in anticipation of tight integration of these interfaces with the sonobuoy�s upper and lower units during Phase III.

PHASE III DUAL USE APPLICATIONS: Integrate the technologies into a logistically supportable sonobuoy package that is compatible with air carriage and air drop for existing and future Navy launch platforms.

The small size, low cost, and standardized form factor of mBuoys will expand market potential enabling new applications and greater use of sensors for ocean and climate research, marine mammal surveys, economic exclusion zone monitoring, and customs and border protection.

REFERENCES:

1. Holler, R. A., Horbach, A. W., & McEachern, J. F. (2008). The ears of air ASW: a history of US Navy sonobuoys. Navmar Applied Sciences Corporation. Warminster, PA, 2008. https://www.worldcat.org/title/ears-of-air-asw-a-history-of-us-navy-sonobuoys/oclc/720627294.
2. Military Analysis Network. (1998, December 12). AN/SSQ-53 directional frequency analysis and recording sonobuoy. Federation of American Scientists. https://www.fas.org/man/dod-101/sys/ship/weaps/an-ssq-53.htm.
3. Military Analysis Network. (2000, April 23). AN/SSQ-62B/C/D/e directional command activated sonobuoy system (DICASS) Sonobuoy. Federation of American Scientists. https://fas.org/man/dod-101/sys/ship/weaps/an-ssq-62.htm.

KEYWORDS: Miniaturized; Tether; Sensors; Antisubmarine Warfare; ASW; Acoustics; Airborne