MIL-STD-3009 is a military standard primary for flight displays and mission avionics controls and displays subsystem for aircraft, and since the cockpit environment has similar lighting conditions encountered by outdoor workers, MIL-STD-3009 is the ideal standard for mobile computers.
MIL-STD-3009 provides a realistic and easy to replicate method of measurement to determine critical factors such as display reflectance and contrast ratio. The measured display performance references have been shown to correlate closely with perceived qualities. A contrast ratio of >3.0:1 is specified as the minimum acceptable level under high ambient illumination (sunlight) conditions. A display with high ambient contrast ratio above 3.0:1 is considered optimal for outdoor viewability.