XN000022-1981-12-27 — Page 2

SUNDAY, DECEMBER 27, 1981

ROYAL OBSERVATORY AMONG THE BEST

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THE ROYAL OBSERVATORY HAS NOW SOME OF THE MOST ADVANCED METEOROLOGICAL EQUIPMENT AND ITS SERVICE COMPARES WITH THE BE: IN THE ASIAN REGION.

BUT ALONG WITH ITS INCREASED SOPHISTICATION, THE OBSERVATORY'S RESPONSIBILITIES HAVE ALSO BROADENED TO ENCOMPASS WORK THAT WEATHERMEN ONLY A FEW YEARS BACK COULD NOT POSSIBLY HAVE IMAGINED,

ITS ASSISTANT DIRECTOR FOR OPERATIONS AND METEOROLOGICAL SERVICES, MR PETER LI SAID.

+FOR INSTANCE, THE OBSERVATORY, IN ADDITION TO ITS TRADITION L' WORK OF WEATHER FORECASTING, HAS BEEN ENGAGED IN AN AIRPORT SITE PLANNING STUDY AT CHEK LAP KOK,+ ADDED MR LI, WHO HAS MORE THAN 15 YEARS EXPERIENCE IN METEOROLOGICAL OPERATIONS.

TO HELP GATHER THE NECESSARY DATA, THE OBSERVATORY HAS PURCHASED TWO DOPPLER ACOUSTIC RADAR SYSTEMS, COSTING A TOTAL OF $3 MILLION. ONE OF THEM HAS ALREADY BEEN INSTALLED AT THE SITE.

MR H.K. LAM, SENIOR SCIENTIFIC OFFICER OF THE OPERATIONS DIVISION, EXPLAINED THE FUNCTIONS OF THESE RADARS 1 +EACH RADAR HAS THREE ANTENNAE - ONE VERTICAL, THE SECOND

INCLINED TOWARDS THE NORTH AND THIRD INCLINED TOWARDS THE EAST. HIGH ENERGY SOUND PULSES ARE TRANSMITTED REGULARLY BY THESE ANTENNAE. THE RADAR DETECTS THE AMPLITUDE AND FREQUENCY SHIFT OF THE ECHOES DUE TO TEMPERATURE DISCONTINUITIES IN THE LOWER LEVELS OF T.. ATMOSPHERE.

+A MICROPROCESSOR IN THE RADAR COMPUTES THE THREE DIMENSIONAL WIND DIRECTION AND SPEED AND GIVES AN INDICATION OF THE HEIGHTS OF THE TEMPERATURE DISCONTINUITIES ON A CHART RECORDER.

+THE SYSTEM IS NOW PROVIDING VALUABLE DATA ON WIND SHEAR (CHANGES IN WIND VELOCITY AT DIFFERENT LEVELS) AND TURBULENCE WHICH ARE IMPORTANT INFORMATION FOR PILOTS DURING AIRCRAFT LANDING OR TAKE-OFF, MR LAM ADDED.

THESE RADAR ARE BASED ON A NEW GENERATION OF TECHNOLOGY WHICH HAS BEEN DEVELOPED ONLY IN THE LAST TWO OR THREE YEARS AND HAVE MANY OTHER POTENTIAL USES.

ANOTHER NEWLY-ACQUIRED METEOROLOGICAL DATA GATHERING SYSTEM WHICH TYPIFIES THE OBSERVATORY'S CONTINUOUS EFFORT TO UPGRADE

ITS SERVICES IS THE CORA UPPER AIR SOUNDING SYSTEM. INTRODUCED IN JANUARY THIS YEAR, THIS SYSTEM HAS MAJOR IMPROVEMENTS OVER THE OLD MANUAL SYSTEM IN USE SINCE 1951.

A RADIOSONDE SUSPENDED FROM A LARGE HYDROGEN-FILLED BALLOON IS RELEASED INTO THE ATMOSPHERE. THE RADIOSONDE CONSTANTLY TRANSMITS ELECTRONIC SIGNALS BEARING INFORMATION ON THE HUMIDITY, TEMPERATURE AND PRESSURE AS IT ASCENDS TO 30 000 METRES. UPPER AIR WIND SPEEDS AND DIRECTIONS ARE DETERMINED FROM THE POSITIONS OF THE RADIOSONDE WHICH IS LOCATED USING OMEGA NAVIGATIONAL SIGNALS.

/THE CORA