Visibility Siting Requirements Human Factors Analyses

Objective: Two human performance metrics, Object Discrimination Analysis and Object Discrimination and Line of Sight (LOS) Angle of Incidence, were used to assess the impact of tower height on air traffic control tower specialist distance perception.

Technical Approach: the tower visibility analysis tool (http://www.hf.faa.gov/visibility) was used to assess the human performance metrics1.  

Air Traffic Control Tower: New Tower
Light Level: Sunlight Clouds
Ground Turbulence: Medium
Target Object: Dodge Caravan, target orientation: Front View
Observer Eye Height: 0
Vertical Elevation Change Between Observer and Key Point (feet): 0
Ground Elevation at Tower (MSL): 0
Ground Elevation at Key Point (MSL): 0
Tower to Key Point Distance: 0 (feet)	0 (km)
Visibility Range: 10(Miles)	16.09 (km)

1.	Object Discrimination Analysis Results

Criteria	Threshold	Tower Results	Pass/Fail	
probability(detection)	95.5%	0%	Fail	
probability(recognition)	11.5%	0%	Fail	

2.	Line of Sight (LOS) Angle of Incidence

Threshold	Tower Results	Pass/Fail	
0.8 degrees or 48 minutes	NaNdegrees	<Field17>