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        + Micro Rain Radar index    
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It is a highly reliable system suitable for use in remote and extreme environments, requiring minimal maintenance and is suited for long term unattended operation.

The MRR provides information for now-casting of precipitation ie, it will detect the start of rain from ground level to high above the radar several minutes before the start of rain at ground level.

The MRR system consists of an antenna dish, radar, receiver unit and RS-232 data transmission interface.

PC based software is available for online control, data visualization, transfer and storage. The MRR can be used to calibrate other radars for better performance

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Specifications of the Vertical Pointing Complete Micro Rain RADAR (MRR-2, FM-CW Mode)

Links to previous pages
+ USA / Canada met index      

Precipitation Section
    + Precipitation index 
        + Micro Rain Radar index    
                - YOU ARE HERE

What it does

The MRR Micro Rain Radar is a compact 24.1 GHz FM-CW radar for the measurement of profiles of drop size distributions and – derived from this – rain rates, liquid water content and characteristic falling velocity resolved into 30 range gates.

Very small amounts of precipitation – below the threshold of conventional rain gauges – are detectable. Due to the large scattering volume (compared to in situ sensors) statistically stable drop size distributions can be derived within a few seconds.

The droplet number concentration in each drop-diameter bin is derived from the backscatter intensity in each corresponding frequency bin. In this procedure the relation between terminal falling velocity and drop size is exploited.

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Frequency: 24.1 GHz (24.1GHz - 24.15GHz)

Modulation: saw tooth type, modulation depends on adjusted height resolution:

for example 1.5 MHz for 100 m height steps
for example 3 MHz for 50 m height steps

Radiated Power: 50 mW

Power Consumption: 25 W @ 24 VDC

 

• Offset parabolic dish antenna, Ø 60 cm, beam width 2 °, 6 dB
• Radar front end (electromagnetic feed), Ø 8 cm x 25 cm
• Transmitter control electronic housing, 26 cm x 16 cm x 10 cm, IP65
• Receiver unit and digital signal processor unit for FFT (Fast Fourier transform) -analysis for derivation of Doppler spectra (10 s sampling time)
• Data transmission with RS232 interface for system control
• 82 ft (25 m) junction cable for data transfer and power supply of outdoor components

• Power supply 110 VAC / 24 VDC / 25 W
  User can use either mains or 24 VDC as both are available.

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Links to previous pages
+ USA / Canada met index      

Precipitation Section
    + Precipitation index     
        + Micro Rain Radar index    
                - YOU ARE HERE

_______________

_______________

Links to previous pages
+ USA / Canada met index      

Precipitation Section
    + Precipitation index     
         + Micro Rain Radar index    
              - YOU ARE HERE

_______________

_______________

The system provides profiles of droplet spectra (i.e. drop size distribution), radar reflectivity, liquid water content and rain rate (with regards to Mie-scattering), signal attenuation and density dependant fall velocity.

System Parameter:

• Sampling time: 10 s *
• Average time: adjustable, 10s to 1800s
• Number of height steps: adjustable, max.30
• Height steps:adjustable, 10m to 200 m
• Lowest measuring height: 2 height steps
• Automatic restart after power breakdown with no loss of settings
• Output of measured data (spectra, reflectivity, rain rate, liquid water content) both as instantaneous and averaged data (with selected averaging interval)

* for the data transmission of the Doppler spectra from the outdoor receiver and FFT-electronic to the indoor data acquisition PC a transfer time of 2-3 s is required. Therefore, for a 10 s sampling time only 7-8 s are used for effective measurements.

There are two pieces of software supplied with the MRR, the first is the controlling software to set the parameters of the MRR and the second is software to view the Doppler spectra and visualize the data graphically for presentation etc. Functionality can be broken down as:

• Software module for system access and control, data transfer and data storage
• Software module for on-line evaluation of Doppler spectra (measured data see above)
• Software module for graphic presentation of results and data with:
• profiles, time series, droplet spectra, statistics or 4- or 9- plot display in a single graphic format
• selectable time and height ranges
• smoothing functions
• printer output
• export capability to *tif, *eps, *wmf, bmp, txt, etc.

The MRR unit requires a PC computer with MS Windows software for the data acquisition and the derivation of the precipitation parameters.

Important note
In Biral provided quotations for MRR systems the price includes a fully compatible desktop / notebook computer, software installation, system calibration and configuration as well as test of components at Biral for complete functionality. If the MRR unit is supplied without a PC you will need to be responsible for this work and compatibility (see below for PC specifications).

WINDOWS 2000 or XP;

600 MHz, Pentium III, 64 MB, 17’’ VGA Monitor, 20.0 GB HD, CD-Writer, 1.44 Floppy, 1 serial, 1 parallel port;

The serial port must be native and not provided over a PC card or USB to serial adapter, as these tend to be unreliable or cause conflicts.

WINDOWS 2000 or XP;

600 MHz, Pentium III, 64 MB, 14,1 TFT VGA Monitor, 8,0 GB HD, ext. CD-Writer, 1.44 Floppy, 1 serial, 1 parallel port; 2 PC-Card slots, Li-Ion Accu

The serial port must be native and not provided over a PC card or USB to serial adapter, as these tend to be unreliable or cause conflicts.

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The images below are an example of the comprehensive illustration facilities provided by the graphic analysis software and include:

• Time series of liquid water content for different heights

• Contour plot of rain rate

• Statistical analysis of rain rate

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Optionally available items to enhance performance of the MRR

Optional heating of the parabolic antenna dish

The optional heating provides strong heating of the antenna dish to ensure error free operation during snow and icing conditions.

An AC / DC converter with appropriate power inputs is included for the region providing 500 Watt heating power, a 25 m cable and the non-removable heating elements which are located on the reverse side of the antenna.

Optional networking ability with RS232/RS422 to 10/100 Mbps Ethernet converter

The basic MRR unit data output is RS232 serial data. With the Ethernet converter it is possible to connect the MRR data output with the network port of the above specified PC. This opens the possibility to connect the data stream to existing local networks for on site data transfer as well as remote maintenance capability.

Please note that a RS232 to USB adapter often cannot provide sufficient performance for the data conversion for several reasons and therefore we can only recommend the conversion to Ethernet protocol.  The Ethernet converter specifications are:

Connector type:  9 way D type (female) to RJ45

Protocols: TCP/IP, UDP, Telnet, DHCP, ICMP, HTTP, SNMP, DNS

Power: 9 to 30 VDC, 200mA @ 12V

Dimensions: 73 x 121 x 27 mm

Operating Temperature: 0°C to 60°C

Weight: 0.44 lbs (0.2 kg)

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Training

Various training packages are available to suit your requirements. Please contact Biral for further details.

Installation

The MRR is delivered with an adjustable mounting adapter, which is suitable for a cylindrical mast with a maximum outer diameter of 48 mm. This diameter is common to scaffolding tubing. The mast has to be installed absolutely vertically with a maximum of one degree of error tolerance. The mast is not included in the delivery.

The MRR is of a high quality and built to have an extremely long life with little to no maintenance.

Biral and Metek have a policy to maintain a stock of replaceable items for 5 years from the date that manufacture ceases and there are no plans to cease manufacture in the foreseeable future. However if we do cease manufacture we could inform you at that time to discuss your requirements for replaceable parts / spares thus ensuring continuity of service.

Biral always offers free support by telephone, email or fax for the lifetime of our sensors regardless of the owner.

The Vertical Pointing Complete Micro-Rain-RADAR MRR-2, FM-CW Mode comes with 1 year parts and labour warranty as standard. For extended warranty please contact Biral for a quotation.

Links to previous pages
+ USA / Canada met index      

Precipitation Section
    + Precipitation index     
        + Micro Rain Radar index    
                - YOU ARE HERE

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The customer / end user is liable for the acquisition of the frequency permission and the operation of the MRR system for the region of use. Biral provides guidance to users in acquiring permission.

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If you would like to print out a formatted version (pdf) of these system details please click info pack

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