Wind Profiler Quality Control
Algorithms and Software
Wind profiling radars are valuable tools to measure winds as a
function of altitude. Traditionally data these devices have been
quality-controlled by determining a consensus of the moment values
over a period of 30 minutes to an hour before using those moments
to calculate horizontal winds. In the context of RAP's aviation
weather projects, the need arose for more rapid update of the wind
values and the concommitant need for quality control not based on
long term consensus.
Human experts have long been used to perform quality control on
specific cases of spectral data for detailed analysis. RAP's approach
in building the NCAR Improved Moments Algorithm (NIMA)
was to use a combination of mathematical analysis, image processing
techniques, and fuzzy logic to try and mimic the human experts skill
in analyzing these spectra. In addition, NIMA provides a confidence
in its calculated moments. These confidence values can be used by
subsequent algorithms in the processing chain.
Further quality control can be provided at the level of the winds
calculation. The NCAR Winds and Confidence Algorithm (NWCA)
utilizes the NIMA moments and confidence values to produce windspeed
and direction measurements. The assumptions used by the model used
to make these calculations are explicitly tested in order to estimate
the confidence in the resulting winds.
The NIMA algorithm has been applied to data from a variety of
wind profilers, primarily 915 MHz boundary layer radars, but also
1290 MHz (DWD Lindenberg) and 50 MHz (Ensco) radars. Experimentally
it has also been used on scanning radar spectral data and lidar
data. The NIMA/NWCA software has been in use operationally since
1998 as part of the Juneau
here to view the MST10 Radar Conference poster, May 2003
A detailed chronology of NIMA/NWCA
Method of moment estimation and feature extraction for devices which
measure spectra as a function of range or time.
- U.S. Letters Patent No. 5,940,523, issued August 31, 1999.
- U.S. Letters Patent No. 6,307,500, issued October 23, 2001.
- Cornman, L.B., Goodrich, R.K., Morse, C.S., and Ecklund, W.L.,
1998: "A Fuzzy Logic Method For Improved Moment Estimation From
Doppler Spectra", J. Atmospheric and Oceanic Technology,
15, p 1287-1305.
- Cohn, S.A., R.K. Goodrich, C.S. Morse, E. Karplus, S. Mueller,
L.B. Cornman, and R.A. Weekley, 2001: "Radial velocity and wind
measurements with NIMA: Comparisons with human estimation and
aircraft measurements", J. Applied Meteorology, 40,
- Goodrich,R.K, C.S.Morse, L.B.Cornman, S.A.Cohn, 2002: "A Horizontal
Wind and Wind Confidence Algorithm for Doppler Wind Profilers",
J. Atmospheric and Oceanic Technology, 19, p 257-273.
- Morse, C. S., R. K. Goodrich, and L.B. Cornman, 2002: "The NIMA
Method for Improved Moment Estimation from Doppler Spectra", J.
Atmospheric and Oceanic Technology, 19, p 274-295.
Contact us for information
concerning no-cost license agreements to obtain NIMA for research
and educational purposes.
Contact: Cory Morse