AWS

1. “Automatic weather station their working
principle and importance”
Course name- Master Seminar
Course No.- AGM-591
Session - 2018-19
Presented by
KHILESH KUMAR SAHU
Dept. of Agrometeorology

2. Automated Observing Sysyetms
Automatic Weather Station(AWS)is a modern electronic integrated system
using software and hardware in which meteorological and other data sensed
by various sensors is acquired automatically with or without physical
attendance from remote or desired site.
An AWS has multifunctional ability of
acuiring,registering,recording,storing,transmi
ting,processing,presenting the various data in
the form of analog, digital or graphic output.
It consists of
Data Logger – The main function of data is to
read and and record automatically the output
from the various sensors. data is
automatically recorded at the exact interval or
time of day or every minute, hours a day for
any weather parameter.
Sensors – Detects various weather
parameters
Telemetry(Optional) – Enable to transfer the
data
Solar Panel – To charge the battery

3. Types of AWS
Real-time AWS
 It records the observations
and sends observations to a
remote network on a real-
time basis, either regularly
or upon request by the user.
 This type of station is used
for ordinary synoptic
meteorological analysis and
monitoring of critical
warning states such as
storms and river or tide
levels.
Off-line AWS
 It records observations on
storage devices & not able to
send to a remote network.
 This type of station is used
for climatological analysis or
as an auxiliary facility to
manual observations.
 Deployed in regions where
no communication lines are
available in order to reduce
observer workload.

4.  Real-time continuous measuring of parameters day-
time and night-time
 More accurate and reliable
 Automatic data archiving and collection of data in a
greater volume
 Higher resolution
 Adjustable sampling interval for different parameters
 Free from reading errors
 Standardization of observations (both time and quality)
 Automatic message generation and transmission
 Access of archived data locally or remotely
Importance of AWS

5. Different type of sensors
Sensor Parameter
Thermometer Temperature
Cup Anemometer with interrupter Wind speed
Wind Vane Wind direction
Capacitive sensor Humidity
Barometer(tranducer) Atmospheric pressure
Ceilometer Cloud height
Tipping bucket Rainfall
Ultrasonic Snow Depth Sensor Depth of snow
Pyranometer Solar radiation

6. Communication Unit
Telephone/Fax line
Satellite Communication
AWS based on GPRS network
AWS
Satellite
Receiving
Station

7. Data Logger
It is the heart of AWS which acts as
interlink between sensors, power
supply and communication system.
It receives data from various
meteorological sensors and store the
values within itself and sends it to the
communication port for transmission.
Power Supply
 The main power source for an AWS
is usually one or more solar panels
connected in parallel with a regulator
and one or more rechargeable
batteries.
 As a rule of thumb, solar output is
at its optimum for only 5 hours each
day.
 In the Northern Hemisphere the
solar panel would be mounted facing
south and vice versa for the Southern
Hemisphere.
 The angle of the panel differs from
place to place but it should never be
mounted with an angle of 5 deg as
dust build up will dramatically
decrease the panel's output.

8. Mast
The standard mast heights used with AWS are 2, 3, 10 and 30m.
The 2m mast (head height) is used for the measurement of
parameters that effect a human subject.
 The 3m mast (crop top) is used for the measurement of
parameters that effect crops (such as wheat, sugar cane etc).
 The 10m mast is used for the measurement of parameters
(wind speed & direction) without interference from objects such
as trees, buildings or other obstructions.
 The 30m mast is used for the measurement of parameters over
stratified distances for the purposes of data modelling and
boundray layer study. A common application is to take
measurements of wind, humidity and temperature at 30, 10, and
2 meters.

9. Disadvantages
Automated observations have also some disadvantages as
follows:
 Limited represented area of 3-5 km of sensor site.
 It is not possible to observe all parameters automatically.
e.g. Cloud coverage and types
 Ongoing periodic maintenance
 Periodic test and calibration
 Well trained technicians and specialists
 High cost of instrumentation and operation

10. CONCLUSION
• AWS is a software which is simple and easy to use.
• It requires no specific programming skill and user can use
it to read and collect the data by simply making use of is
user id.
• In addition to this data is saved in a format which is easy
to understand and read such as HTML,MS Excel, word,
PDF etc.
• Due to its wide range of profitability by AWS even the
private companies from India and abroad are showing
intrest in this field such as Indiamart ,Ecotech etc.