URSI Session "Large Scale Science Projects: Europe – Africa Connects"The 11th IEEE AFRICON conference, September 9 – 12, 2013, Mauritius

ndjuric@uns.ac.rshttp://semont.ftn.uns.ac.rs

Ministry of Education, Science and Technological Development

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Nikola DjuricFaculty of Technical Sciences, University of Novi Sad

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

2/15

Content

The concept of the SEMONT monitoring system. The broadband monitoring approach. The monitoring bands. The EM field register. The exposure assessment approach. The SEMONT system utilization. Internet web portal. Conclusion.

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

3/15

The SEMONT system concept

Serbian electromagnetic field monitoring network – SEMONT.

GSM network

Internet

Urban area

CCS

User

Sensor

GSM base stationSource of EM field

Radio and TV broadcasting

Power lines

Fig. 1. System implementation over the area of interest.

Concept

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

4/15

Broadband monitoring approach

Provide information on the overall EM field level, without considering which sources are active over the area.

Fig. 2. The broadband isotropic EM field monitoring.

GSM network

Internet

Internet portal

User

Sensor

Source of the EM field

Ex(t)

Ez(t)

)()()()( 222 tEtEtEtE zyx

Ey(t)

Radio and TV broadcasting

GSM base station

Wi-Fi systems

Broadband

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

5/15

The monitoring bands

The SEMONT sensor nodes performs broadband monitoring in multiband frequency ranges.

Fig. 3. The monitoring bands.

GSM network

Internet

Internet portal

User

Sensor

10 Hz – 5 kHz

EGSM 900 EGSM 1800 UMTS 2100

Low frequency bandpass

High frequency bandpass

Sensor

100 kHz – 6 GHz

Bands

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

6/15

The EM field register (1/2)

The SEMONT system employ broadband measurements in combination with continuous monitoring, offering a history overview of field fluctuation during a period of time.

Fig. 4. The broadband isotropic EM field monitoring.

GSM network

Internet

CCS

User

Sensor

24h

E[V/m]

0h

Time

Short interval of conventional measurement

Source of EM field

History overview

Field register

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

7/15

The EM field register (2/2)

The SEMONT system is intended for remote, the 24 hours a day monitoring, utilizing sensor nodes with considerable internal memory, solar panel and rechargeable batteries.

Table. 1. Memory and monitoring period of the sensor.

Sampling interval Monitoring duration

30 sec 5 days

1 min 10 days

2 min 20 days

6 min 60 days

15 min 169 days

Field register

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

8/15

The exposure assessment approach (1/3)

Generally, the conventional measurement requires an extrapolation to the maximum power of source, since the “worst case” method is the only way to gain information on the exposure level that can be present in some area.

Fig. 5. Example of extrapolation of EM field level.

Gathering results over GSM network

Internet

User

Sensor

24h

E[V/m]

0h

Time

Source of EM field

CCS

Measurement in one moment

Extrapolated field level

Daily fluctuation

Exposure

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

9/15

The exposure assessment approach (2/3)

The continuous measurements overcame the problem of missing the period of the most intensive radiation of sources. The SEMONT monitoring is performed during the 24-hours period.

Fig. 6. Daily limits of the global exposure ration (GER) assessment.

GSM network

Daily limits of GER

Sensor

Internet

User

24h

GER

0

Upper GER level

Lower GER level

Source of EM field

CCS

Exposure

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

10/15

The exposure assessment approach (3/3)

Exploiting an approach of continuous monitoring, the SEMONT system assesses the GER and calculates lower and upper limits of daily exposure, according to the Serbian prescribed limits and ICNIRP recommendations.

For high-frequency electric field:

For the low-frequency magnetic field:

where real exposure will be in the range

2

min

2

max

ref

mup

ref

mlow E

EGERand

E

EGER

minmax ref

mup

ref

mlow B

BGERand

B

BGER

.low real upGER GER GER

Exposure

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

11/15

The SEMONT system utilization (1/2)

The low-frequency application – overhead power lines are well known sources of the low frequency magnetic and electric field.

Fig. 7. Monitoring field near overhead power lines.

GSM network

Internet

CCS

User24h

B[T]

0h

Time

Overhead power lines

History of field level

Utilization

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

12/15

The SEMONT system utilization (2/2)

The high-frequency application – the EM fields register simplifies procedure of the first and periodic testing of the radiation sources, as well as licensing the installation of new sources.

Fig. 8. Testing of the radiation sources.

GSM network

Internet

CCS

User24h

E[V/m]

0h

Time

New base station

History of field level

Utilization

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

13/15

Internet web portal (1/2)

Fig. 9. Presentation of the measurement results.

1:n

1:n

Sensor 1 Sensor 2 ...

Location 1 Location 2 ...

Measurement 1 Measurement 2 ...

Basic data for the particular sensor node

Internet

Web portal

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

14/15

Internet web portal (2/2)

Web portal

Fig. 9. Presentation of the measurement results.

The Concept of the SEMONT Monitoring System and its Influence on the EM Pollution Protection

Concept

Broadband

Bands

Field register

Exposure

Utilization

Web portal

Conclusion

15/15

Conclusion

The SEMONT system introduces an approach of wireless sensor network utilization for a daily supervision of overall and cumulative EM field level.

The SEMONT system is able to offer respectable answers regarding the public concerns on actual and long-term exposure to EM radiation.

The system provides information on the overall EM field level at any instant of time, without considering which EM sources are present and active over the observed area.

It is convenient if it is necessary to inform the general population, without technical knowledge on EM field sources.

The SEMONT system could be a significant support for the local authorities in their efforts to perform systematic care considering health effects of non-ionizing radiation.

Conclusion