RAWS/AWS* Tech Note

Fire and Aviation Management Staff       	 	   RAWS/AWS* TechNote-2000-03
Watershed and Air Management Staff

Date: 	07 November 2000

System: 	RAWS/AWS

Subject: 	Time of Measure (observation) vs Transmit Time for Remote Automated Weather Stations 

Purpose: 	Communicate and explain the official (NWCG’s Fire Danger Working Team) standard for time of measure corresponding to time of transmit for remote automated weather stations transmitting data to the GOES satellite.

Contact: 	Kolleen Shelley 	208-476-8362		kshelley@fs.fed.us
	Linnea Keating	208-476-8312		lkeating@fs.fed.us
	Buddy Adams		208-387-5475		Buddy_Adams@blm.nifc.gov

Info:	A memo containing the following direction regarding time of measure and time of transmit for NFDRS RAWS stations was issued by the Fire Danger Working Team on February 1, 2000.  This memo was distributed to all vendors of RAWS equipment currently supplying GOES transmitters to the Wildland Fire Community.  Owners of weather stations should assure that their station complies with this standard.

********************************

“It has come to the attention of the National Wildfire Coordinating Group’s Fire Danger Working Team that there is potential confusion on the timing of weather station measurements and transmission when using the Geostationary Operational Environmental Satellite (GOES).  The following standard applies to GOES telemetered automatic weather stations owned and operated by wildland fire agencies that support fire prevention, preparedness, suppression and fire use activities. 

GOES telemetered station sensor update readings will coincide with the assigned transmission time.  The instantaneous readings must be taken within the 5 minutes up to and including the transmit time.  Futher, if 10 minute averages are taken, the sensor average readings must be taken within the 15 minutes prior to the assigned GOES transmission time.  Example: if a station transmits to GOES at 45 minutes past the hour, the sensor instantaneous readings must be taken between 40 and 45 minutes past the hour and the averaged readings must be taken between 30 and 45 minutes past the hour.

The intent of this standard is to provide the wildland fire community with the most near real time data as possible.  This is in no way intended to limit the capability of your product for more frequent sampling intervals; in fact, we encourage the flexibility in measurement and transmission capabilities.  This standard is only meant to apply to measurements transmitted via the GOES satellite.  

In the event you offer “preprogrammed” and/or programs with the data collection portion of the processes “predefined”; the purchaser will need to provide you with the assigned GOES transmission time for the program to be within this standard.

We hope this clarifies any discrepancies in directions you may have received from the wildland fire community regarding this matter.  Should you have any questions, please don’t hesitate to contact Gary Curcio, Chair Fire Danger Working Team.”

For more information on the activities of the NWCG’s Fire Danger Working Team, please visit www.nwcg.gov, click on working teams and select the appropriate link.