Workload Transition Implications for Individual and Team Performance (1993) / Chapter Skim
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7 Geographic Orientation
7 Geographic Orientation
Pages 171-197
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From page 171... ...
This chapter focuses on some of the general factors involved in the development of the team commander's model of the world and how those factors affect his geographic orientation and workload. Although each of the factors mentioned above mediates a tank commander's battlefield success, his ability to maintain geographic orientation (i.e., awareness of one's location in the world)
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From page 172... ...
For tank commanders or helicopter crews, geographic orientation refers to their knowledge of the environment through which they are moving and to the relationship between where they are, where they should be, and where they are going. Since the visual scene is continuously changing, geographic orientation is a dynamic process.
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From page 173... ...
The earth's gravitational field determines a locally unique upright that is orthogonal to an approximately flat surface. When, as observers, we are constrained to this surface, we possess: (1)
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From page 174... ...
Thus, earth latitude/ longitude coordinates would provide a very poor reference system for locating features on the surface of Mars, and position relative to streets in New York yields poor localization for places in Trenton. The third type of reference frame is an object-centered frame, in which locations and directions are defined relative to fixed landmarks (e.g., mountaintop, valley, outlook tower)
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From page 175... ...
The navigator attempts to maintain congruence between his position and orientation in a world frame specified by a physical or cognitive map (see Tolman, 1948, for a discussion of cognitive maps) and what he can see in his ego frame (e.g., his forward field of view)
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From page 176... ...
This forward mental rotation is used to compare a mental image with the perspective forward field of view. Evidence for the reality of these mental rotations can also be found in studies by Aretz (1988~; Cooper and Shepard (19731; Shepard and Metzler (1971~; Eley (1988~; Evans and Pesdick (1980~; Harwood (19891; Hintzman et al.
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From page 177... ...
As a consequence of invoking the rotation heuristic, people tend to remember figures as being more rotated in memory such that their primary axes are oriented so as to be similar to the principle axes of the reference frame (Braine, 1978~. Since vertical and horizontal are natural axes for describing both figure and frame in sensation, perception, and language, these are the most likely candidates for rotation (Rock, 1974~.
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From page 178... ...
For example, during a recent field study, emergency medical services (EMS) helicopter pilots were asked to draw maps of their service areas.
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From page 179... ...
Whether or not these biases exert significant influence on the absolute recognition procedure employed in a navigational task is unclear. For example, would a tank commander or a locomotive conductor become confused if the viewed curvature of a mountain is greater than the simplified (i.e., straightened)
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From page 180... ...
Timing While orientation in space is an important issue addressed by the concept of frame of reference, the equally important issue of orientation in time is not. Many aspects of the tank commander's duties involve timing: arriving at initial battle position on schedule, crossing way points on time, and
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From page 181... ...
Although most commanders wear watches, continuous monitoring is not possible because other tasks require their attention. Thus, temporal orientation involves more than whether or not the tank commander has a watch.
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From page 182... ...
Depending on how time estimation is distorted, landmarks may be expected too early, yielding a premature sense of lostness, or too late, creating the possibility that a landmark would be overlooked if it was passed before it was expected. Mental Models of Navigational Tasks Since there are many ways to solve a complex problem, the solutions most likely to occur to a researcher are those that arise from the traditional assumptions of his or her own culture.
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From page 183... ...
Hence, the model he proposed consists of components derived from research in the area of visual perception and spatial cognition, coupled with information gained by consultation with operational pilots. The components of the model are presented in Figure 7.1, which provides an integrated framework for the information that preceded this section and can be used to integrate the tank commander's task for the consideration of workload transition.
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From page 184... ...
The automobile driver and fixed-wing aircraft pilot can usually follow their selected route with little regard for surrounding terrain features, in marked contrast to the tank driver and rotorcraft pilot (during low-level flight) , who must use surrounding terrain features to identify the route to be followed.
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From page 185... ...
During a mission, helicopter or tank crews view features in the external scene and compare them to a paper map or their mental images. They must mentally transform the stylized images on two-dimensional maps into mental images, which represent a perspective view of the object, which is rotated into alignment with the forward field of view, for comparison with the
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From page 186... ...
At this point, the crew must take action to reestablish their position. A helicopter pilot might gain altitude or a tank commander drive to the top of a hill to find a distinctive landmark.
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From page 187... ...
. During premission planning, helicopter or tank crews plot their route on the map, identify critical choice points, and select additional features that they will use to verify their position.
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From page 188... ...
In a tank, the commander is responsible for navigation, passing verbal steering commands to the driver; particularly when the tank is buttoned up because the driver's field of view is too restricted to maintain geographic orientation. Helicopter or tank crews use or mix a number of different frames of reference when exchanging information among themselves or transmitting to another vehicle: (1)
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From page 189... ...
Helicopter pilots and tank commanders during premission planning use both object and container reference systems. On a map, which is usually oriented north-up, distinctive objects (terrain features)
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From page 190... ...
In developing a mental model of the mission area, the tank commander might mentally rotate the north-up map into a track-up perspective to visualize the route and to brief the platoon commanders. In communicating the plan to battalion headquarters, it is likely to be expressed in polar coordinates with reference to a north-up map, so the plan can be correlated with that of other teams.
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From page 191... ...
Transition From Rear Staging Position to Initial Fighting Position The accuracy with which a tank commander must know his team's position during the move to the initial point depends on the proximity of other friendly and enemy positions and the degree to which a precise transition to the initial fighting position is critical to mission success. That is, if the team is trying to stay masked during the transition, then required accuracy could be very high; if surrounded by enemy forces, maintaining a route designed to maintain cover is critically important.
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From page 192... ...
If artillery or close air support is needed, the tank commander, through his fire support officer, would determine where and how much artillery or close air support is required, in relation to their current position. Again, this requires a translation between a world view (artillery and close air support)
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From page 193... ...
Low-cost electronic chart display systems coupled with global positioning satellite (GPS) receivers are being developed to determine and display the exact position of a vehicle superimposed on a map, a task currently performed by the tank commander using paper maps, at a considerable cost in time and cognitive effort.
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From page 194... ...
Also, electronic maps must depict the sort of features tank commanders and helicopter pilots actually use for geographic orientation, represented in a form that is most compatible with the way the feature will appear in the forward scene. By reducing the workload associated with navigation, all of the features should allow the tank commander more resources to deal with
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From page 195... ...
Santa Monica, California: Human Factors Society. 1991 The design of electronic map displays.
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From page 196... ...
Hart, S.G. 1978 Subjective time estimation as an index of workload.
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From page 197... ...
GEOGRAPHIC ORIENTATION 197 Wickens, C.D. 1989a Attention and skilled performance.
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