LAP3000 1290 MHz WINDPROFILER/RASS

Specification
parameter value
Owner KNMI
Manufacturer Vaisala (formerly Radian)
Radar Type: Pulsed Doppler
Antenna 2.7 x 2.7 m2 micropatch phased array
Beam Elevation 90° and 74.5°
Peak Power 500 W
Frequency 1290 MHz
Time Synchronisation network time-server
Beam Width
Measuring Range: High Mode: 500 - 5500 m, Low Mode: 150 - 2000 m, RASS: 150 - 1800 m
Range Resolution: High Mode: 400 m, Low Mode: 100 m, RASS: 100 m.
Sampling Interval: High Mode: 200 m, Low Mode: 60 m, RASS: 60 m.
Software: LAPXM 2.4.1.0
   

Description:

(to be included)

Processing:

The routine operational acquisition program consists of measuring in wind mode for 55 min. and in RASS mode for 5 min. each hour resp. In wind mode one cycle consists of 10 measurements each: 5 in low mode and 5 in high mode. Low and high mode measurements are interleaved and the beam position sequence is LV-HV-LE-HE-LS-HS-LN-HN-LW-HW where L=Low Mode, H=High Mode, V=Vertical, E=East, S=South, N=North and W=West resp. The azimuth angle of the oblique beams is E=112°, S=202°, N=22°, and W=292° resp. One cycle takes approximately 5 min. of measuring and processing time. The Doppler spectra are processed in real-time and the first three moments of the strongest peak of each spectrum are calculated. The velocity of the strongest peaks are used to compute an hourly consensus averaged wind speed, direction and temperature. A quality analysis based on the Weber-Wuertz algorithm is applied to the consensus averaged winds and temperatures.

Products:

(to be included)

History:

The LAP3000 windprofiler was installed in Cabauw in July 1994. The profiler is located approximately 300 m. south of the 213 m high meteorological tower. Since the installation the profiler has been operated continuously. However in the early years of operation data acquistion was frequently interrupted due to problems with software and storage on optical disk. Since the system is connected to the network of the KNMI early 2000 a high reliability of the measurements is achieved. In spring 2000 cup-anemometers have been installed in the tower. Reflections of the cup-anemometers sometimes disturb the wind measurements of the profiler between 300 and 400 agl. Also in spring and autumn occasionally during night time, but mainly in the first few hours after sunset, song bird migration can disturb the measurements.

Contact:

Henk Klein Baltink
KNMI
PO Box 201
3730 AE De Bilt
the Netherlands
Telephone: +31 30 2206476

References:

  • Carter D.A., K.S. Gage, et al.,"Developments in UHF lower troposperic wind profiling at NOAA's Aeronomy Laboratory", Radio Science, 1995, Vol. 30, No. 4., 977-1001
  • Rogers R.R., W.L. Ecklund, D.A. Carter, et al, "Research Applications of a Boundary-Layer Wind Profiler", Bulletin of the American Meteorological Society, 1993, Vol. 74, No. 4, 567-580
  • Angevine W.M., S.K. Avery, W.L. Ecklund, D.A. Carter,"Fluxes of heat and momentum measured with a boundary-layer wind profiler radar-radio acoustic sounding system", Journal of Applied Meteorology, 1993, Vol. 32, pp. 73-80.
  • Weber B.L., D.B. Wuertz, D.C. Welsh, et al.,"Quality Control for Profiler Measurements of Winds and RASS Temperatures", Journal of Atmospheric and Oceanic Technology, 1993, Vol. 10, No. 4, 452-464.

Image:

profiler

General information

Cabauw 40 year

Instruments

Publications

CESAR Consortium

CESAR Database