360-Degree OmniDisplay System
Lieutenant Monroe wrote this article while a student at SOAC. It was the winner of The Naval Submarine League award for class 96050. He is now Navigator/Operations Officer on USS CITY OF CORPUS CHRISTI (SSN 705).
After clearing baffles and raising the scope, the Officer of the Deck (OOD) gives the order to proceed to periscope depth. Looking forward, he concentrates on the OmniDisplay centered overhead. As the scope breaks the water, seas prove to be state 4 as predicted by sonar, but the digitally-stabilized display maintains level with the horizon. During his initial visual search, the OOD notices that the ship is JO degrees off course and corrects the helm,· the ship is now back on course. On the horizon there are two visual contacts detected: a merchant and an aircraft. The view is digitally magnified on both contacts and the system automatically begins tracking both contacts, providing observations to the fire control system transparent to the OOD as he reviews the navigation plot, with the JOOD maintaining a visual search. ESM alerts the OOD that an enemy aircraft radar has been detected, but is very weak. Deciding to take a closer look, he calls up the zoom view and magnifies the aircraft 128 times and sees that it is an enemy fighter, but is flying away with no counter detection suspected.
Just moments before going coming down from PD sonar detects a submarine. The OOD immediately goes deep and maneuvers to avoid. He looks at the sonar display, called up as a window on the OmniDisplay, and sees that the screen has become quite con. fusing with six merchants and two warships now displayed. He becomes concerned as he considers how to tactically employ the ship, as well as sort out all the data. Quickly sweeping a glance around the OmniDisplay, he sees the enemy submarine displayed on the port beam drawing aft. Having a confident picture of the tactical situation, the OOD deftly maneuvers the ship into optimal position moments before the Captain makes it to the conn.
Why is it that the OOD on a surfaced submarine stands his watch on the bridge? What benefit is so great that the OOD is separated from his watchstanders and the navigation plot, and braves the freezing winds and cold waves over the bridge windshield-it is the panoramic view. The clear 360 degree view afforded by standing watch high in the sail optimizes the most vital sensor to safely navigating a submarine on the surface. While it is obviously more thrilling for the 000 to stand watch on the bridge, all the activity pertinent to his watch is occurring below in control, making the increase in the safety of ship well worth the loss of some direct supervision over the watchstanders.
While on the surface, standing watch on the bridge is possible, but this option clearly does not exist while the ship is submerged at periscope depth. In these cases the OOD is restricted to a view with a width limited to that of the magnification of the scope and is compelled to dance with the one eyed lady while making the periodic high and low power sweeps. How then can we gain the benefit of the 360 degree panoramic view while submerged and at the same time free the OOD from the physical constraints of the periscope?
The latter part of this question has already been answered with non-penetrating periscopes with which, using high definition video cameras, the OOD can conduct a visual search from a monitor in control. This technology has already been tested on several ships and will be incorporated into future classes of submarines.
However, it is the first part of the question which I intend to answer in this paper, focusing on a completely different method of displaying information for the OOD. The technology that I propose is not, to my knowledge, under development, but instead is an idea which I feel is worth serious consideration.
Figure 1 shows the fundamental element of the system which I propose: the OmniDisplay. This is a 360 degree display which is centered in the overhead above the conn allowing the 000 a clear view of the display and of the control room. This display will give a panoramic view from the scope at periscope depth using a completely different optics system, discussed later, or can be used to display the multitude of screens that the OOD must contend with on the conn (e.g. Sonar, WLR-9, JMCIS, etc.). Figure 2 shows the view of the OOD from the conn looking forward.
The proposed scope design is comprised of three component sections and is shown in Figure 3. These sections are the Antenna Group, the Omni Group and the Zoom Group. The Antenna Group is self explanatory. The Omni Group is the primary component for use with the OmniDisplay. It uses an inverse conical mirror to focus a 360 degree image onto a flat plane for the video camera. A similar conical mirror arrangement is used to project the images on the conn OmniDisplay. However, there are some restrictions in vertical coverage and magnification would be limited to a digital zoom with reduced resolution by expanding the individual image pixels. The solution to this problem is the third group of the scope. The Zoom Group would use a servo controlled mirror and traditional optics to magnify an image, improving resolution. It also allows for viewing of objects at high elevation.
All images would be processed by a single microcomputer. Input from the Omni Group, the Zoom Group, as well as sonar, fire control, E.M., radar, JMCIS, and ships parameters would be processed into a single 360 degree display above the conn. Visual images are digitally stabilized by horizontally fixing the image on the visual horizon. The system would also automatically track visual contacts and could estimate range and angle on the bow. In contact rich environments, this would be a valuable aid and backup for the OOD. Figure 4 shows what the display may look like while submerged. Obviously no visual data may be displayed, but contacts can be visually stimulated and displayed (note the submarine and merchant ship in the figure below) based on the fire control solution, better aiding the OOD to maintain a full understanding of the tactical picture. Since the display is simply a screen with a digital image projected onto it, the system allows for windows to be placed at the users discretion, allowing a great deal of flexibility for future modifications as technology continues to develop.
The display system which I propose would have the following
Digital and optical zoom
Unified display of all contact and sensor data on the conn
Easy upgrade and/or modification
Allow for a scope with low radar cross-section
Assist the 000 in maintaining spatial orientation of the threat
Make use of COTS (commercial off-the-shelf) image processing
Submarining has at its very heart technology, but it is those who tactically employ the ships who are most essential to its success. To that end, improvements to submarines should not be merely applications of new technologies because they are available, but should directly enable the crew in better sensing and understanding the threat environment in order to best fight the ship. The display enhancements which I have proposed will assist the 000 in maintaining a clear picture of the threat environment, benefitting safety of the ship in peace time and aiding the ship’s primary mission in wartime.
Back at periscope depth and having cleared datum, the OOD overhears the Captain, who is in his stateroom, discussing the recent hostile submarine encounter with the Battle Group Commander on EHF. Control is still filled with the battle stations watchstanders as phones and coffee cups are put away. There is discussion of battle damage assessment by a P-3C who is dropping sonobuoys over the datum. Suddenly, an alien from the visual tracking system detects an incoming aircraft and zoom reveals it to be a P-3C Orion, probably the one that was just discussed. Doing a quick sweep to ensure that no other masts are raised and realizing that all comms are lined up on the scope, the OOD then continues as the Orion with its /SAR radar safely passes overhead without detecting the submarine below.