Transcript الشريحة 1 - Royal Netherlands Meteorological Institute

Egyptian Meteorological Authority (EMA)
Koubry ELQuobba EMA , Cairo , Egypt , P. BOX :
11784
Vaisala GPS
station
Fax : 00202 226852789
[email protected]
Abstract
Egyptian Meteorological Authority ( EMA ) will begin
a new development technology for Upper air ground stations at jun
2010 by adding new sounding system SR2K2 MODEM with radio sond M2K2-DC from France and new technology for
communication of network of the stations .
also EMA have 6 upper air stations which used the sounding system of Digicora iii with Radiotidotite RT 20A ( Vaisala )
from fenland .
So since 2007 we started to use new development technology with the GPS wind finding system (Vaisala) , for three upper air
stations in (Matrouh at 2007 , Asswan at 2008 and Helwann at 2009 ) to using Digicoraiii with Radiotidotite RT 20A
and GPS wind finding system.
In this paper We will compare between the different of observations from RDF and GPS system.
Also , we will use DigicoraIII dual-mode GPS/RDF wind finding and Modem GPS data Comparison flights executed in Asswan ,
Marsa Matrouh and Helwan stations , during 2007 to 2010 by the EMA .
Global Positioning
System (GPS)
GPS
Signal
Path
There are two system in upper air stations
1-Upper Air sounding system SR2K2 Modem
consists in collecting P,T,U, and wind finding data measured and transmitted from a Radiosonde M2K2-DC
during its flight through upper atmosphere layers which used M2K2-DC (Dual Core) GPSonde that
is already widespread in the operational SYNOP upper-air network of major and National Met.
Services.
M2K2 GPSonde successfully participated to the latest WMO inter-comparison of High-Quality
Radiosondes, Designation of High-Quality Radiosonde is fully applicable to MODEM’s M2K2
GPSonde
2-The DigiCORA® Sounding System MW31 with the Radiotheodolite RT20A and GPS wind finding
( Vaisala ) contains :-
A-Radiotheodolite RT20 system
Radiotheodolite windfinding is best suited for situations where the balloon elevations remain above
about 16°, so we using the stations of Radiotheodolites in the summer season .
B-GPS wind finding system
portable system with small antennas for 403 MHz telemetry and GPS wind finding RS92-SGP
Radiosonde for GPS wind Technology, Major Features All-digital code-correlating GPS
Radiosonde Higher level of PTU measurement performance Continuously available, highly
accurate wind data code correlating GPS .
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max height by m
Max height of wind for Matroh station
from (dec2007 to feb2008) GPS
35000
30000
25000
20000
15000
10000
5000
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
no of observations
Dec2007
Jan2008
Feb2008
We compare between the two upper air systems vaisala and Modem :In the fig (1), (2) and (3) we used system of Modem of upper air sounding system in the 14 jun 2010 we
used Modem system and in the fig (4),(5) and (6) the day of 14 jul 2010 we used Vaisala system this data for Marsa
matroh , Asswan, and Helwan stations .
In the fig (7) it the statistics for data of max height of wind speed from( Dec 2007 to Feb 2008 ) with using vaisala
upper
air sounding system we found the data of wind speed and direction for all observations reach to about (30-20) kms .
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Asswan station in Egypt it is one of The Upper-air Network (GUAN) which consists of stations selected from the Global
Observing System of the World Weather Watch. Criteria for choice of sites included homogeneity, a history of high quality
observations .
The data flow for the GUAN begins with national centers that collect and submit the data to the international system.
The data collected by the network of GUAN stations are transmitted on the GTS in the form of upper-air reports (TEMP and
CLIMAT TEMP).
International centers perform quality control on the data, prepare data products for users, and archive it for future users.
Some of these international centers prepare routine reports on the performance of the system.
Summary Of GUAN for Asswan Station
Range time
WMO
STATION
OBS LVLS
00Z 12Z AVGPRS >100 >50 >10 TEMPS DPDS WINDS
(2007 /8 ) 62414
ASSWAN, EGYPT
30
1780
30
0
52.9
27
27
0
1075
630
1157 ( Air upper air st.)
(2008 /8)
62414
ASSWAN, EGYPT
28
2097
28
0
26.2
27
26
0
1129
693
1410 ( vaisala upper air st.)
62414
ASSWAN, EGYPT
29
2541
29
0
16.8
28
28
4
1225
770
1817 ( vaisala upper air st.)
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(2009 /9)
(2009/11-4) 62414
ASSWAN, EGYPT
179 16893 179
0
23.3
(2010 /4) 62414
ASSWAN, EGYPT
30
0
22.6
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2914
30
171 166 4
30
27
1
8215
5071 11446 ( vaisala RDF&GPS upper air)
1344 820
2064 ( vaisala RDF upper air st.)
We found that seine using Air sounding system we used 500 kg of Metrological balloon which burst at latitude less than 30 km and
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fill with Hydrogen gas by using Sagim system so we found that the number of significant levels for temperature , dew point and wind in
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Air system is less than when used Vaisala system for GPs and RDF system .
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