As of 20 December 2001

• Location
  All weather sensors are mounted on top of a building at JSC. Wind, humidity, pressure, and temperature measurements are mounted on a 30 foot pole. These sensors are approximately 172 feet (52 meters) above sea level. Tipping bucket rain gauge is mounted on the roof below the pole.
  Sensor siting may cause readings to be non-representative. For example, temperature measurements on clear, cold nights with light winds will likely be higher than surrounding observations at ground level due to temperature inversion effects. Be sure to check surrounding stations for a spatial validity check.

• Model HMP45C Temperature and and Relative Humidity Probe
  • Temperature sensor
    • range: -40C to +60C
    • accuracy: +/- 0.5C from -40C to +60C (0.2C at 20C)
  • Humidity sensor
    • range: 0 to 100%
    • accuracy at 20C: +/- 2% at 0 to 90% RH, +/- 3% 90 to 100% RH
• CS105 Barometric Pressure Sensor
  • pressure range: 600mb to 1060mb
  • total error: +/- 2mb 0C to 40C (0.5mb at 20C)
• RG2500 Tipping Bucket Precipitation Gauge
  • accuracy: +/- 1% for 1 to 3 inches per hour
  • accuacy: +/- 3% for 0 to 6 inches per hour
  • calibration: 0.01 inches per tip
  • reset to zero at 0600 central time (as of 12/20/01)
• RMY05103 Wind Monitor
  • 4 blade propeller anemometer
    • range: 0-134 mph
    • accuracy: +/- 0.6 mph
    • starting threshold: 2.2 mph
    • gust survival: 220 mph
    • distance constant: 8.9ft (63% recovery)
  • Wind vane potentiometer
    • accuracy: +/- 3 degrees
    • starting threshold: at 10 degree displacement 2.0 mph
• Data Sampling
  • Raw sensor data: once every 10-30 seconds
  • Altimeter: instantaneous sample
  • Temperature: instantaneous sample
  • RH: instantaneous sample
  • Wind Speed Averaging period: two minutes
  • Wind Direction: instantaneous (software limitation of CR500 datalogger)
  • Gust: highest instantaneous speed measurement in past two minutes
  • Message file: web files updated about every 2 times per hour

• Disclaimer
  SMG makes no claim to ownership, quality, timeliness, presence, and reliability of the JSC weather data. All accuracy claims mentioned above are from the sensor manufacturers. Maintenance, environmental, and other factors will likely affect the accuracy of the data. SMG does not own the sensors. SMG is a user of the data and provides these experimental measurements as a public service. Data from the sensors should not be relied upon for the protection of life and property. Maintenance, both hardware and software, is provided by a NASA contractor. Please read the NWS disclaimer concerning distribution of data to the Internet.

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