ISRO Center (Govt of India)

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MINI Boundary Layer Mast (MBLM) ~ cost = 25 lakhs

Earth’s atmosphere is an ocean of air, hundreds of kilometers thick, which protects life from the sun’s intense heat and dangerous radiation. The behavior of the atmosphere is quite complex. In fact, every day we all make decisions which are somehow influenced by the weather.

Weather and climate are global phenomena. Winds, solar radiation and various activities that take place on the earth affect the weather and cause long term changes in the climate. So studies related to weather and climate are of utmost importance.

This demands a number of observational centers and a strong database. Indian Space Research Organization (ISRO) has taken up this challenging task. ISRO has set up a large number of automatic weather stations (AWS) across the country.

PRWONAM (Prediction of Regional Weather with Observational Meso-Network and Atmospheric Modeling) is a unique project of ISRO under which 28 stations of Mini Boundary Layer Mast (MBLM) are proposed to be established.

1. To transfer MBLM data to R & D room without cable and pen drive.

The basic intention of this project is to reduce human effort with the help of technology. The sensors attached to the MBLM tower gives the data at 1 sec frequency. The data logger records the readings which are taken in a pen drive at the same resolution. Due to memory limiting capacity of the pen drive, it has to be replaced by an empty pen drive every week, to avoid loss of data. To reduce the effort in collecting the data every week, the students aim to establish a wireless connection that can directly send the data every second to the R & D center.

The Concept:

To transfer MBLM data to R & D room without cable and pen drive.

Conventional data lines or cord cables have been replaced and wireless technology has been extensively used in recent times. The latest addition in wireless communications has been ZIGBEE. Similar to Wi-Fi or any other wireless communication methods, zigbee also uses radio waves for the transmission of data. But what gives ZIGBEE its edge over others is its range, data transfer rate and reliability. Max-stream technologies have designed two convenient modules called XBee and XBee Pro. Both of these operate at 2.4 GHz frequency range.

However, it is the range which is the main difference between the two. The normal XBee module provides a line of sight range of ~ 100 m whereas XBee Pro can transfer data up to 1 mile efficiently. Xbee uses 802.15.4 protocol. These XBee modules posses unique properties like PAN id and Destination address that make the communication link reliable. These XBee modules can be interfaced with a pc using usb interfaces that interface the XBee module to a pc using USB 2.0. Therefore these XBee modules can be used to establish an uninterrupted link between the site and the base station (our college in our case).

Non – Interference to the presently operating system:

The MBLM records data every second and an average of 4 min is sent to Bangalore via a GSM module. Since even GSM uses radio waves for communication, a question of interference may arise. However, that is not an issue in this case since GSM modules operate at a frequency of 900 – 1800 MHz and the frequency of ZIGBEE is much higher (~2.4 GHz frequency band). Thus the interference of signals is completely ruled out.

Any Modification to Data Logger?:

Modification to Data Logger
Since the readings from the sensors are being written into the pen drive with the help of a data logger, a question arises if any modification is required in the data logger for establishing the wireless connection. The answer to this is NO. The implementation of this wireless set up will be completely external, with no disturbance to the existing modules. Our wireless module will be attached externally through the usb port. A splitter will be placed, which will split the single port in the data logger to 2 ports. In one of them, the pen drive will be placed and the wireless setup will be placed in the other port. To get a better idea, a picture of the splitter is attached below.

Reliability & prevention of Data loss :

A major concern for implementing this project is the reliability of transmission and prevention of loss of data. XBee Pro provides a line of sight range of 1.5 km with reliable data transmission. However, our requirement is only that of about 300 to 400 m (distance between the college and the tower). Hence data transmission is highly reliable.

Since we are placing a splitter and retaining the pen drive at the site, the data will also be written into the pen drive along with being transmitted wirelessly. Hence, in case of large data losses through wireless communication, the data of the past week can still be retrieved in case of an emergency. Hence the loss of data is also not a major concern.

Conclusion:

Therefore, using ZIGBEE communication for the transmission of data is a feasible solution, which can help us to receive every second data and process it simultaneously with the help of some software.

Data mining using MBLM data:

This algorithm has been developed by the B. Tech. students of VBIT for the usage of the research scientists. The requirements of the scientists were explained to the students which demanded immediate access of the particular data (specific data and time) to the scientists. Every second data needed to be averaged over different time intervals as per the requirement of the problem. The students took it up as a live project and developed the software which could even be used for direct graphical representation.