OFFICE OF SURFACE WATER TECHNICAL MEMORANDUM 2009.08
SUBJECT: Availability of a New Feature for Loading Data to the Instantaneous Data Archive (IDA)
The purpose of this memorandum is to announce the availability of a new feature to allow the direct uploading of data to the Instantaneous Data Archive (IDA) without requiring quality-assurance checks against published daily values.
Since its launch in 2006 (Office of Surface Water Technical Memorandum No. 2006.03), the IDA database (http://ida.water.usgs.gov) has grown to include 2.5 billion unit values from over 8,500 stations in 45 Water Science Centers (WSC). Currently all of the data loaded to the IDA are quality assured and classified based on how closely the instantaneous data reproduces the published daily mean value. The current classifications are as follows:
0 - A daily mean discharge calculated from the instantaneous data on this day is 0.01 cubic feet per second or less and the published daily mean is zero.
1 - A daily mean discharge calculated from the instantaneous data on this day matches the published daily mean within 1 percent.
2 - A daily mean discharge calculated from the instantaneous data on this day matches the published daily mean from 1 to 5 percent.
3 - A daily mean discharge calculated from the instantaneous values on this day matches the published daily mean from 5 to 10 percent.
One limitation associated with this approach is that it precludes loading instantaneous data to the IDA that have not been used to publish daily mean values. An example of this limitation is data from estuaries and other tidally affected systems where daily means are not computed for non-filtered data and thus there is nothing for the IDA quality-assurance checks to run against.
To fix this limitation, a new option has been added to the IDA retrieval process to allow a WSC to bypass the quality-assurance checks and to load discharge data directly to the IDA. When used, the WSC assumes all responsibility for ensuring that the data are correct. The classification used in the IDA for such data is:
9 - The instantaneous value is considered correct by the collecting USGS Water Science Center. A published daily mean value does not exist and/or no comparison was made.
It is important to note that, currently, the IDA is still limited to discharge data (NWIS parameter code 00060). In the case of data from tidal systems, however, tidally filtered discharge is not currently supported in the IDA.
Information on the new option, to load instantaneous data to the IDA that have not been used to publish daily mean values, can be found at: http://hexe.er.usgs.gov/usgs/ida/index.html .
We appreciate the strong response to the IDA from many of the WSCs since its release and encourage all WSCs to make use of the new feature as appropriate. Also, we request that the WSCs who have yet to load data to the IDA to do so and for all the WSCs to annually load the new instantaneous values collected in the previous water year.
|Stephen F. Blanchard /signed/
Chief, Office of Surface Water
Delaware River Master
U.S. Geological Survey
National Center, MS 415
12201 Sunrise Valley Drive
Reston, VA 20192