SOME APPROACHES TO AUTOMATIC DRAWING METEOROLOGICAL MAPS BY COMPUTER 
Liu Qizhen, Xu Jianhua, He Yongbao 
Computer Science Department 
Fudan University 
220 Handan Road, Shanghai 200433 
China 
ABSTRACT 
In this paper some approaches to automatic drawing meteorological maps by computer are 
introduced. Meteorologists or weather analysts can get 6 kinds of thermodynamic and dynamic 
maps of atmosphere by use of these methods conveniently and immediately. 
Keywords: Cartographic, Computer Graphics, Mapping, Remote Sensing Application 
1. INTRODUCTION 
In the case of nowcasting or short-term casting, 
meteorological experts need a useful tool to draw the 
meteorological maps by use of remote sensing data, such as 
balloon air sounding data, meteorological satellite data and 
so on. We developed following 6 kinds of drawing 
projects(more than one hundred meteorological maps) for 
choosing: 
(1) Distribution maps of wind, temperature, humidity, 
pressure, rainfall and so on. 
(2) Streamline of atmosphere. 
(3) Time-height cross section and 
section. 
(4) Isogram of functional difference of thickness advection. 
(5) Isogram of vertical stability of convection. 
(6) Superimposition of graph and image. 
space-height cross 
2. DRAWING METHOD AND DRAWING RESULT 
(1) Distribution map of essential meteorological factors 
This program can draw distribution maps of temperature, 
humidity,pressure, wind direction and wind velocity, 
rainfall, number of station and other statistical data. 
At first, classify the factor data to N levels and give 
different color, character size and italic angle to the 
different level, then write the data at every stations'position 
of map. So the distribution map can display information 
distinctively. 
When we want to draw the wind distribution map, the 
program can draw wind signals by following formulas: 
T = V ;/:20 (1) 
L = (Vj - 20T)/:4 (2) 
S - (V;-20T-4L)/:2 (3) 
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where V; is the wind velocity of the i station , T,L,S is the 
number of 20m/s, 4m/s, 2m/s wind feathers, /: means the 
result of division is an integer. 
Fig.1 is the examples of distribution maps. 
(2) Cross section 
There are 2 kinds of cross section in the meteorology. One 
is the time-height cross section, another is the space-height 
cross section. For drawing the space-height cross section, 
we developed a method for searching stations in a square 
area. We also developed a rule of limited neighbor density 
to screen out suitable stations. Using the wind data of 100 
hPa pressure layer of the first chosen station, draw a wind 
signal on the 0 point of coordinate, then remove and rotate 
the wind signal to a corresponding position (Xj, Y;) by 
following formula, 
cosw sinw 0 1 00 
X'Y 1]=(XY1]* | -sinw cosw Of * | 0 10 
0 0. 1 X; Y; 1 
(4) 
where (X* V5) is the coordinate of wind signal after 
removing and rotating, (X,Y) is the coordinate of wind 
signal before removing and rotating, w is the degree of 
wind direction. 
Then draw the wind signal of 150 hPa pressure layer of the 
same station, then 200 hPa, 250 hPa, ‚1000 hPa, 
ground, layer by layer. Then draw the wind signals of the. 
second chosen station,..., station by station, until all wind 
signals of all chosen stations were drawn. 
Finally, draw the constant value curves of temperature, Osce 
or another meteorological factor on the map. 
Fig.2 shows a typical cross section map