Which data are reported by certified direct-reading instruments? (Variant of ATIS data)

• A. Wind direction, velocity, and altimeter
• B. Density, weather observation, and temperature
• C. Dew point, temperature, and visibility
• D. Ceiling, dew point, and density

Answer: (A)

Direct readings from certified sensors used for automated weather broadcasts are wind direction, wind speed, and the altimeter setting. The wind direction is read from a wind vane, the wind speed from an anemometer, and the altimeter setting comes from the barometer/altimeter sensor. These readings are taken directly from the instruments without needing calculation, which is why they’re the data listed for ATIS-type direct readings. Other items, like density, dew point, visibility, and ceiling, rely on calculations or separate sensing systems and are not the basic direct readings provided by the certified instruments in this context.