Proceedings of the Symposium on Tactical Meteorology and Oceanography: Support for Strike Warfare and Ship Self-Defense (1996)

The Symposium on Tactical Meteorology and Oceanography: Support for Strike Warfare and Ship Self-Defense was held by the National Research Council's Ocean Studies Board on September 11-14, 1995, at the U.S. Naval Air Station in Fallon, Nevada. Jointly supported by the Office of the Oceanographer of the Navy and the Office of Naval Research, the symposium emphasized the role of meteorology and oceanography in strike warfare and ship self-defense. Within the Navy, the term METOC is used extensively to refer to meteorology and oceanography. This term appears frequently throughout this report, especially during discussions of these disciplines and their relationship to strike warfare and ship self-defense, or the relevant research community.

Meteorological conditions are the dominant environmental factor affecting strike warfare and ship self-defense; however, ocean effects within the marine boundary layer also are significant. The offensive and defensive systems aboard Naval aircraft assigned to strike missions can be adversely affected by visibility, temperature, humidity, and atmospheric refractivity. Similarly, ship self-defense sensors and weapon systems may be adversely influenced by visibility, winds, and atmospheric refractivity. To take advantage of the maximum capability of these weapon systems and achieve mission success, it is paramount that naval forces be able to adapt to and exploit METOC effects.

The symposium brought together members of the U.S. Navy (fleet operators, meteorologists, and oceanographers) and scientists, technologists, and managers from naval warfare centers and defense programs to discuss means to:

• address timely operational problems, fleet mission needs, and other areas in which METOC research and development solutions need to be developed;

• enhance communication and interchange among the basic and applied research communities, as well as with naval forces engaged in strike warfare and ship self-defense; and

• enable an extended group of researchers to become familiar with challenging naval issues that are uniquely or strongly applicable to the strike warfare and ship self-defense METOC regime.

This report is intended to summarize the discussions that took place during the symposium. All of the comments and suggestions included in this report represent the opinions of the symposium attendees, and do not necessarily reflect the views of the Ocean Studies Board or the National Research Council.

Strike warfare and ship self-defense were addressed in two separate consecutive sessions. Each session began with a summary of the mechanics, tenets, and basic tactics of operations aboard Navy ships and aircraft. Next, participants were organized into working groups that focused on three issues related to exploiting the METOC environment: (1) environmental models, (2) atmospheric effects, and (3) sensors and weapon systems.

The Environmental Models Working Group raised many issues, ranging from the data collection and assimilation needed to initialize and verify models, to the user-friendly nature of the output data and communication capabilities required to ensure their timely receipt and use. The most critical METOC parameters influencing strike warfare and ship self-defense are cloud cover, winds, precipitation type and amount, sea-surface and air temperature, sea state, and currents (e.g., infrared-seeking instruments are critically dependent on "point-specific" temperature contrast and visibility). In addition, operational planning requires forecasts for the target area, including routes to and from the area, 24 hours prior to a launch. Not only are present METOC models unable to predict hazardous weather along a track route, they fail to provide sufficient horizontal and vertical resolution or accuracy for effective operational planning.

Weather modeling and optical turbulence research, with the ability to accommodate both seasonal changes and diurnal stability events, are key requirements for METOC. The Navy's Electro-Optical Tactical Decision Aid (EOTDA) supports visual and infrared-range predictions using the Thermal Contrast Model (TCM).

Development of high-resolution nested models for the Naval Operational Regional Atmospheric Prediction System (NORAPS) and high-resolution shipboard atmospheric models with boundary-layer capabilities would represent valuable technological achievements. The capability of these new models to perform data and model uncertainty assessments would be a critical link in their development. The Environmental Models Working Group also strongly advocated the reporting of confidence levels for near- and long-term modeling results. Other specific points raised by members of the Environmental Models Working Group during the symposium include:

• the need to run models onboard ships at sea, due to limitations on communications speeds;

• the need for models to better account for small-scale processes affecting coastal atmospheric conditions;

• the need for more rapid assimilation of observational data;

• the advantages and disadvantages of ensemble forecasting techniques;

• the value of toggle-switched modeling techniques;

• the need for the fleet to understand the practical limits on forecast precision; and

• the need for better awareness on the part of modelers of the operational significance of various environmental factors.

The Atmospheric Effects Working Group discussed numerous factors that could improve the capabilities of tactical METOC. Improved techniques were suggested for data assimilation, sensor-to-model integration, and product dissemination. It was also noted that improved airborne unmanned autonomous vehicles (UAVs) and satellite remote sensors (e.g., lidar, radiometer, and satellite imagery data geographically linked to the NAVSTAR global positioning system [GPS]) would significantly enhance existing tactical METOC capabilities. In addition, the working group discussed atmospheric effects in the context of improving atmospheric models and sensors. There is a need to improve the fleet's ability to perform METOC analyses, based almost exclusively on remotely sensed data.

An improvement in the observation and measurement of such variables as clouds, refractivity, and visibility, to the degree that improvements support small-scale environmental models, also is desired. Efforts must be made to exploit space-based collection of atmospheric and oceanic data. It is imperative that greater use be made of all available data for briefing and debriefing. Fusion and assimilation of conventional environmental data with unconventional data, such as from the GPS, should lead to improved modeling. To tactically exploit the sea-skimming cruise missile environment for ship self-defense, models will have to be tuned specifically to allow for characterization of the complex, coupled ocean-atmosphere environment near the surface layer. Other specific points raised by members of the Atmospheric Effects Working Group during the symposium include:

• the need to better understand geographic variance of atmospheric parameters;

• the need for better sensor-to-model integration and data dissemination;

• the relative merits of in-situ versus remotely sensed data and data collection strategies;

• the overall need for improved environmental observations; and

• the need to improve upon the Navy's present ability to forecast atmospheric conditions (e.g., cloud formations) that may limit the fleets ability to detect a threat or conduct successful strike operations.

The performance of strike and ship self-defense systems depends on a variety of factors sensitive to METOC conditions, especially radio frequency (RF) transmission and refractivity. Guidance systems are affected by target appearance (temperature differences), cloud ceilings, visibility, and wind, whereas self-defense and strike operations are affected by RF refractivity, EO and infrared (IR) transmission, sea-surface characterization, and high-resolution atmospheric

profiles. The working group indicated that, to address these problems successfully, special attention must be given to the proper role of remote versus in situ technologies (e.g., unattended ground sensors), satellite observations, and ship sensors (e.g., SPY-1 radar) in data collection. Priority should be placed on research that focuses on integrated sensor management systems, mesoscale METOC characterization, improved operator awareness, and the ability to distinguish actual sensor clutter from the effects of sea state.

The working group also indicated that modeling and database concerns must be addressed throughout the acquisition process, particularly during the evaluation of cost considerations and during testing. In addition, operational planning requires forecasts for the target area, including routes to and from the area, 24 hours prior to the launch and evaluation phases. The working group also called for acceleration of the development of shipboard atmospheric modeling capabilities and the integration of accurate METOC data into fire control systems. Other specific points raised by members of the Sensor and Weapons Systems Working Group during the symposium include:

• the limitations on relevant METOC technology transfer to and from the civilian sector, arising from inherent differences in military and civilian applications;

• the need for increased proficiency at observing and predicting environmental conditions, with particular emphasis on 3 zones: 100 km from shore, 100 km inland, and within a radius of 100 km around the ship;

• the need to continue to explore new mechanisms for collecting relevant environmental data (e.g., ship-mounted sensor arrays, ground-base sensor systems, sensors dropped from tactical aircraft); and

• the need for greater understanding on part of the METOC user community of the limitations imposed by the physics of the system on future improvements in fleet capabilities.