scholarly journals Improving Wind Profiler–Measured Winds Using Coplanar Spectral Averaging

2004 ◽  
Vol 21 (11) ◽  
pp. 1671-1678 ◽  
Author(s):  
Robert Schafer ◽  
Susan K. Avery ◽  
Kenneth S. Gage ◽  
Paul E. Johnston ◽  
D. A. Carter

Abstract A method is presented that increases the detectability of weak clear-air signals by averaging Doppler spectra from coplanar wind profiler beams. The method, called coplanar spectral averaging (CSA), is applied to both simulated wind profiler spectra and to 1 yr of archived spectra from a UHF profiler at Christmas Island (1 October 1999–30 September 2000). A collocated 50-MHz wind profiler provides a truth for evaluating the CSA technique. In the absence of precipitation, it was found that CSA, when combined with a fuzzy logic quality control, increases the height coverage of the 1-hourly averaged UHF profiler winds by over 600 m (two range gates). CSA also increased the number of good wind estimates at each observation range by about 10%–25% over the standard consensus method.

1994 ◽  
Vol 12 (8) ◽  
pp. 711-724 ◽  
Author(s):  
P. A. Miller ◽  
M. F. Barth ◽  
D. W. van de Kamp ◽  
T. W. Schlatter ◽  
B. L. Weber ◽  
...  

Abstract. The National Oceanic and Atmospheric Administration (NOAA) has completed the installation of a 30-site demonstration network of wind-profiling radars in the central United States. The network is being used to demonstrate and assess the utility of wind profiler technology in a quasi-operational environment, and to help define operational requirements for possible future national networks. This paper describes two automated quality control methods designed to remove erroneous winds from the hourly network data. Case study examples and statistical evaluation of the performance of each method are also presented.


2012 ◽  
Vol 29 (12) ◽  
pp. 1731-1743 ◽  
Author(s):  
Robert E. Barbré

Abstract This paper presents the process used by the Marshall Space Flight Center Natural Environments Branch (EV44) to quality control (QC) data from the Kennedy Space Center’s 50-MHz Doppler radar wind profiler (DRWP) for use in vehicle wind loads and steering commands. The database has been built to mitigate limitations of using the currently archived databases from weather balloons. The DRWP database contains wind measurements from approximately 2.7- to 18.6-km altitude at roughly 5-min intervals for the August 1997–December 2009 period of record, and the extensive QC process was designed to remove spurious data from various forms of atmospheric and nonatmospheric artifacts. The QC process is largely based on DRWP literature, but two new algorithms have been developed to remove data contaminated by convection and excessive first-guess propagations from the median filter/first-guess algorithm. In addition to describing the automated and manual QC process in detail, this paper describes the extent of the data retained. Roughly 58% of all possible wind observations exist in the database, with approximately 100 times as many complete profile sets existing relative to the EV44 balloon databases. This increased sample of near-continuous wind profile measurements may help increase launch availability by reducing the uncertainty of wind changes during launch countdown.


2008 ◽  
Vol 26 (9) ◽  
pp. 2597-2612 ◽  
Author(s):  
C. Gaffard ◽  
J. Nash ◽  
E. Walker ◽  
T. J. Hewison ◽  
J. Jones ◽  
...  

Abstract. Ground based remote sensing systems for future observation operations will allow continuous monitoring of the lower troposphere at temporal resolutions much better than every 30 min. Observations which may be considered spurious from an individual instrument can be validated or eliminated when considered in conjunction with measurements from other instruments observing at the same location. Thus, improved quality control of atmospheric profiles from microwave radiometers and wind profilers should be sought by considering the measurements from different systems together rather than individually. In future test bed deployments for future operational observing systems, this should be aided by observations from laser ceilometers and cloud radars. Observations of changes in atmospheric profiles at high temporal resolution in the lower troposphere are presented from a 12 channel microwave radiometer and 1290 MHz UHF wind profiler deployed in southern England during the CSIP field experiment in July/August 2005. The observations chosen were from days when thunderstorms occurred in southern England. Rapid changes near the surface in dry layers are considered, both when rain/hail may be falling from above and where the dry air is associated with cold pools behind organised thunderstorms. Also, short term variations in atmospheric profiles and vertical stability are presented on a day with occasional low cloud, when thunderstorms triggered 50 km down wind of the observing site Improved quality control of the individual remote sensing systems need to be implemented, examining the basic quality of the underlying observations as well as the final outputs, and so for instance eliminating ground clutter as far as possible from the basic Doppler spectra measurements of the wind profiler. In this study, this was performed manually. The potential of incorporating these types of instruments in future upper air observational networks leads to the challenge to improve the observing systems and also to exploit measurements at high temporal resolution in numerical weather prediction. These examples are intended to inform potential operational users of the changes in atmospheric structure that can be observed with the new types of observing system.


Author(s):  
SHING I. CHANG ◽  
CRAIG A. ALSTATT

Parameter design has been an effective technique for quality improvement. One of the goals of parameter design for a manufacturing process is to manipulate process parameters to produce an acceptable quality level for the desired quality characteristic. This research explores the concept of implementing parameter design for a turning process using fuzzy logic as an alternative approach for parameter design and quality control. A fuzzy logic controller (FLC) is proposed to manipulate process parameters to find the proper setting for the desired part quality. In this research, we focus on a turning process with surface finish as the desired quality characteristic. The proposed FLC manipulates the most influential parameter, feed rate, while holding other parameters constant to find the proper setting of the parameters necessary for the level of surface finish required by the part. The proposed FLC is found to be an effective method for implementing parameter design for a turning process. In addition, the FLC is shown to be a robust tool through its ability to handle two types of material and two different tool geometries.


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