Difference between revisions of "HIP:wind"
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* Wind direction is recorded in degrees from true north [[http://www.ofcm.gov/fmh-1/pdf/E-CH5.pdf 5.5.1]]. | * Wind direction is recorded in degrees from true north [[http://www.ofcm.gov/fmh-1/pdf/E-CH5.pdf 5.5.1]]. | ||
* Average wind direction and speed is determined by averaging the values over a 2-minute period [[http://www.ofcm.gov/fmh-1/pdf/E-CH5.pdf 5.4]]. | * Average wind direction and speed is determined by averaging the values over a 2-minute period [[http://www.ofcm.gov/fmh-1/pdf/E-CH5.pdf 5.4]]. | ||
− | * Wind gusts are the maximum instantaneous speed in the past 10 minutes | + | * Wind gusts are the maximum instantaneous speed in the past 10 minutes [[http://www.ofcm.gov/fmh-1/pdf/E-CH5.pdf 5.5.4]]. |
== Standards == | == Standards == |
Revision as of 14:42, 3 April 2006
Colin will look into how to do damping of the direction and speed readimg.
Contents
HIPs Standards
- Instantaneous velocities are sampled every 30 seconds.
- Wind direction is recorded in degrees from true north [5.5.1].
- Average wind direction and speed is determined by averaging the values over a 2-minute period [5.4].
- Wind gusts are the maximum instantaneous speed in the past 10 minutes [5.5.4].
Standards
Federal Meteorological Handbook
- [Federal Meteorological Handbook No. 1] - Surface Weather Observations and Reports
Indiana State Climate Office
- http://shadow.agry.purdue.edu/sc.hly-faq.html#q11
- Measures once every second, averaged every 5 seconds. The 5 second averages are used in the 2-minute average.
Databases
Placement
- The international standard for anemometer height above the ground is 10 meters (33 feet) with no obstructions. [2]
Keeping Records
Sampling Standards
- Mean Wind Speed and Direction: 2-minute mean of speed and direction sampled [2]
- Wind direction is recorded in degrees from true north [1 19][2 ].
Data Sampling
Farmland
- http://shadow.agry.purdue.edu/cgi-bin/map_patrol/images/cd_zen.map?162,104
- Lists wind direction, speed, and gust.
METAR
Calculations
- The mode is consisidered the prevailing wind direction. [1 19]
- Dividing each recording into a north-south and east-west vector, averaging them, and then reassembling the vectors. [1 19]
Sampling Standards
- Mean Wind Speed and Direction: 2-minute mean of speed and direction sampled before the observation valid time sampled from high-resoluation data (minimum: 5 second instrument polling).
- Gust: Maximum 'instantaneous' wind value observed in the 10 minutes before the observation time.
External Links
- International Weather Watchers Observer Handbook
- CWOP Weather Station Siting, Performance, and Data Quality Guide
- Averaging Wind Speed and Direction
- Wind Energy Resource Atlas of the United States
- Vector vs. Scalar Averaging of Wind Data
- http://www.ndbc.noaa.gov/wndav.shtml
- http://www.windustry.org/resources/WIND%20PROSPECTING_Monitoring%20at%20Site_FEB05.pdf