Concept:
+ EASILY UNDERSTOOD CONCEPTUAL BASIS:

Ring

Above is a summary matrix of the pros and cons of Ring Heliodon methodology. The best method varies with each user and each situation.


This heliodon is easiest to understand in that it replicates the real-life experience of the sun moving through the sky from east to west across a given site. Therefore, conceptually it is best when trying to understand the general pattern of sun and shadow movement across a site.

Accuracy:
- LIMITED DEVICE ACCURACY:
Due to the divergent nature of a point source of light (ie. the sun lamp), the further a model is from the light source, the more accurate the casting of shadows. The design of this device places the sun lamp very close to the model. As a result the accuracy of the shadow casting is compromised, particularly toward the edges of the pool of light projected onto the table surface. The shadows are most accurate at the exact center of the light beam on a direct axis from the lamp center to the position at which it points on the table surface. For the greatest accuracy it is best to take the model outdoors into actual sunlight with a sun peg sundial on a clear sunny day. This will place the "sun lamp" approximately 93 million miles away from the model.

Operational Complexity:
+ SIMPLE OPERATION: The device is self-contained and fairly straightforward to use.

Model Complexity:
+ SIMPLE MODEL CONSTRUCTION AND ADJUSTMENT:
The model sits on a flat surface with the sun lamp being the only thing in motion. Therefore loosely constructed study models may be used on this device. This allows some quick, simple changes to be made to the model during testing (within the restrictions of facility rules limiting model construction within the space).

Model Size:
- SMALL MODEL SIZE:
The device manufacturer suggests a zone of reasonable accuracy for models that are no larger than 12" long by 12" wide by 6" high. Within this zone, accuracy is greatest at the center of the light beam and diminishes toward the edges. This directly influences the scale of models that can be studied on this device. Some issues of scale can be overcome by studying only a sub-portion of a larger model that is placed within the devices zone of accuracy.

Mobility:
+ MOBILITY OF DEVICE:
The device is movable within the Heliodon testing facility.

Weather Dependency:
+ WEATHER INDEPENDENCE:
Use of this method is not dependant upon Muncie weather.

Availability:
- MANAGED USER AVAILABILITY:
Use of this method is restricted by the schedule and policies of the CERES heliodon facility.