TSUNAMI WARNING SYSTEM Submitted by Name: Arjun Rao RUID: 126004102 Date: 04/02/2010 Course: Communication Networks 2 Instructor : Dipankar Raychaudhuri
Contents
1. Introduction………………………………………………………………………………… 2. Proposed System for Pacific Coast………………………………………………………… 3. Description of proposed system…………………………………………………………….. 4. Table of requirements……………………………………………………………………….. 5. Addressing Scheme………………………………………………………………………….. 6. Data Transmission Formats………………………………………………………………….. 7. Frame Formats……………………………………………………………………………….. 8. Routing Mechanism………………………………………………………………………….. 9. Notification System………………………………………………………………………….. 10. Protocol Stack………………………………………………………………………………. 11. Bandwidth calculations……………………………………………………………………… 12. Cost Analysis………………………………………………………………………………… 13. Possible Problems and Future work…………………………………………………………. 14. References……………………………………………………………………………………
1. INTRODUCTION
What is a Tsunami
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A tsunami is a series of water waves caused by the displacement of a large volume of a body of water, such as an ocean. Due to the immense volumes of water and energy involved, tsunamis can devastate coastal regions. A tsunami can be generated when convergent or destructive plate boundaries abruptly move and vertically displace the overlying water. Subduction zone related earthquakes generate the majority of tsunami. Tsunamis have a small amplitude (wave height) offshore, and a very long wavelength (often hundreds of kilometers long), which is why they generally pass unnoticed at sea, forming only a slight swell usually about 300 millimeters (12 in) above the normal sea surface. They grow in height when they reach shallower water, in a wave shoaling process described below. A tsunami can occur in any tidal state and even at low tide can still inundate coastal areas. Tsunamis in deep water can have a wavelength greater than 300 miles (482 kilometers) and a period of about an hour. When the ocean is 20,000 feet deep, a tsunami travels at 550 miles per hour. At this speed, the wave can compete with a jet airplane, traveling across the ocean in less than a day. Because a wave loses energy at a rate inversely related to its wavelength, tsunamis can travel at high speeds for a long period of time and lose very little energy in the process. In extreme cases, the water level can rise to more than 50 feet above sea level for tsunamis of distant origin, and over 100 feet for tsunamis generated nearby. An earthquake may generate a tsunami if the quake occurs just below a body of water, is of moderate or high magnitude and displaces a largeenough volume of water. •
Need for a Warning system
The need for a Tsunami warning system is highlighted by the damage that can be caused in the event that there is no such system. It is to provide this buffer time for evacuation so as to prevent any lives from being lost that we need a Tsunami Warning System. The characteristics of a warning system should be as follows: Rapid Alerts - The system must be able to relay the message to everyone in danger as quickly as possible. There can be less than 30 minutes between the time of detection and the arrival of the tsunami, so the warning must be distributed in substantially less time. Sending out a warning must be an automatic procedure whenever there is danger from a tsunami. Redundancy and reliability - Every area of the coast must have multiple ways of receiving the warning so that failure of one method will not leave anyone unwarned. All parts of the system should be reliable and durable to prevent failure. Clarity - The system must clearly convey what actions need to be taken. Giving clear instructions about which areas are in danger and which are safe is crucial to avoid confusion and save lives. Ambiguity in information should be avoided as far as possible. Continuous communication - The system should be able to provide the people with updates on new developments, such as when returning to the evacuated areas will be safe. 2. PROPOSED SYSTEM FOR THE PACIFIC COAST •
Features of the revamped network i.
ii. iii.
The system should be robust and extremely reliable. One of the main aspects of this project is the fact that reliability of the system is of utmost importance since the costs that could be incurred are huge. An erroneous prediction will not only result in increased costs in terms of fiscal loss, but it will also result in catastrophic human losses. The system needs to service the entire western pacific coast of the United States ranging from Washington to California. This is a length of 1293km which needs to be serviced efficiently. There will be a communication network connecting the sensor buoys to the Central Command Center. There are two provisions for this via a local area connection of fiber optic links and the second one is via satellite.
iv. The Central Command Center will process the data from the sensors, buoys, airships, satellites and seismometers and then give a reliable source of warning to the people who are most likely to be affected by the tsunami. The central command center is assumed to be located in Northern California for purposes of convenience. v. Keep alive signals are sent by the buoys, sensors and seismometers to the C entral Command Center[CCC] to ensure that the instruments are working in order and are giving satisfactory results. vi. A network of tidal gauges [water level sensors] provides the signal for immediate evacuation within 30 minutes before the tsunami hits the coast. vii.The CCC will also be responsible for maintaining the entry for the particular incoming signal and the ID of the device making that request. viii.There are multiple modes of communication for warning the people and this includes the use of mobile telephony, messaging, televisions, radio and a host of other measures to ensure the warning message is distributed to everyone concerned. ix. Redundancies have been introduced at all stages in order to ensure there is no single point of failure and to ensure that the warning message reaches everyone at any possible time. x. Wired communication is considered to be the primary modes of communication and the provision for wireless communication is made in order to act as back-up. The reason wired [fiber optic] has been chosen as primary is because it is extremely reliable in all conditions even if there are thunderstorms which may cause interference if the LOS method is used for satellite. Moreover, the fact that there is provision for both means of communications highlights the diversity of this method. Services provided
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i. ii. iii.
iv. v.
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Data from the sensors to the CCC will be provided by the buoys, airships, aero planes, tidal gauges, seismometers and satellites Rapid transmission of data from the detecting devices to the CCC with the use of high-speed fiber optic cables and satellites Not only is the warning message about the tsunami given but also detailed information to the CCC including parameters such as direction, time of arrival, speed of tsunami, images of the tsunami detection area, magnitude of earthquake causing tsunami, destruction capability of tsunami, GPS coordinates of the sensors, buoy ID and IP addresses of the sensors. Storage of all data received on a central server to act as a record for previous actions taken based on given set of data. Rapid notification system based on immediate routing of emergency message to all the people who might be affected by the tsunami.
Factors affecting cost
It must be noted that this is a high cost system since most of the technology when integrated is still in its nascent stages. Also this is a very unique system in the s ense that it is being deployed in a very adverse environment and hence in order to ensure reliability and surety of information multiple redundancies are introduced. This increases the cost but makes sure that the people are warned of the danger at the correct time. Some of the factors affecting cost are: i. ii. iii. iv. v. vi. vii.
Pressure sensors and transmitting buoys Seismometers Tidal Gauges Airships [Future Work] Fiber optic cable network for entire system Leasing satellite link Setting up Central Command Center with notification system
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High level topology design
The Tsunami Warning System consists of two main sections. The first one is the warning system and the second is the notification or alert system. The warning system is the crucial aspect of this system as the core information of the system is being obtained from this section. It consists of a number of subsystems which are sensor devices and whose function is to relay the tsunami warning to the Central Command Center which will then take the appropriate action. This appropriate action is the prerogative of the notification system which analyses the parameters obtained from the various sensor devices and relays/broadcasts it to as many people as possible if the need arises. 3. DESCRIPTION OF PROPOSED DESIGN •
Components of System
A) Warning System It consists of the following parts: a) Pressure Sensor and Transmitting Buoy b) Tidal Gauge c) Seismometer d) Airplane e) Airship [Future work] f) Satellites B) Notification System a) Central Base Station b) Cellular Phones c) Television d) Radios e) To Boat [Ham Radios] f) Sirens g) Airplane [With signs/banners] h) Tone Alert Radios
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Details
a) Pressure Sensor and Transmitting buoy
The primary mode of tsunami detection is using a underwater pressure sensor. The pressure sensor is a 0–10,000 psi model. The transducers use a very thin quartz crystal beam, electrically induced to vibrate at its lowest resonant mode. The oscillator is attached to a Bourdon tube that is open on one end to the ocean environment. This device is capable of detecting a change in the height of the sea as small as 1cm at a depth of 6000m. It takes a reading of the pressure every 5 seconds and relays it to the transmitting buoy by use of an acoustic link.
The transmitting buoy performs multiple operations. When there is no indication of a tsunami from the pressure sensor, it is continuously sending ‘keep alive’ signals to the Central Command Center [CCC] every 2 seconds. The primary connection between the transmitting buoys and the CCC is the fiber optic cable network undersea. However, as a backup means of communication, in case of failure of this link, there is also the provision of wireless transfer of data to the CCC via the telecommunications satellite. Now the pressure sensor sends the pressure readings via the acoustic link and these readings are sent to the Central Command Center. If the readings indicate that there might be a tsunami, then the following actions are taking place: 1) A signal is sent using Line of Sight [LOS] propagation to the satellite telling it to take images of the area surrounding the particular buoy and beam these to the CCC. This is because satellite images can also indicate the presence of a tsunami based on the undulations of the waves on the water surface. This technique could have also been used in the tsunami of 2004. 2) The signal is also beamed to the overhead airplanes whose indication is provided by the CCC. The airplanes are given the information that there is an impending tsunami of a certain disaster level detected around the current buoy and that this information must be relayed to the CCC when it flies overhead. 3) In case the provision for the airships is present, then there is intercommunication between the airship and the buoy to provide the Doppler readings for the region in consideration. It should be noted that the transmitting buoy is connected to the fiber optic cable network directly with a fiber optic link that is going towards the seabed. This is not in danger of being cut by boats and ships as they are
advised to move at a certain minimum distance away from these buoys. To prevent cable damage due to shark bites, this connecting cable is enmeshed in a titanium ring mesh which is immune to shark bites thereby preventing the integrity of the cable. It should be noted that the fiber optic cables that carry the information to the mainland are divided into two backbone networks. One backbone services the outer 6 buoys, 3 seismometers and 12 water level sensors while the other backbone services the inner 6 buoys, 2 seismometers and the remaining 12 water level sensors. The reason two sets of cables are used to transfer the information is because there is no single point of failure and even if one cable does break, the probability that the other cable breaks as well is very low and hence the warning will always be transmitted to the mainland.
The arrangement of these transmitting buoys and pressure sensors is crucial to the accurate detection of a possible tsunami. Since the design is required for the west coast, which lies in the seismic active “Pacific Ring of Fire” belt, these pressure sensors must be placed in the appropriate region. Hence, in order to cover the entire length of the coast, 12 buoys are used arranged in two semi-circular arrangements of 6 buoys each. One set of buoys is kept close to the coast at distances of ~100-200 miles since this is the extent of the earthquake prone region. Another set of buoys is kept about ~3000 miles from the coast in order to detect the deep-sea earthquakes which may cause tsunamis. An arrangement of these buoys is as shown in the figure. The reason the semi-circular arrangement is chosen because at any point of time if a tsunami occurs, at least 2 buoys will be in the path of the incoming tsunami. Hence if one buoy / pressure sensor fails, the data can always be obtained from the other buoy thereby not providing any single point of failure.
b) Tidal Gauges
These are provided as a final means of alerting the coast about the impending tsunami. There are 24 tidal gauges in the network arranged in two rows of 12 gauges each, at distances of 100 m and 500 m respectively. The operation of these tidal gauges is on the principle of “Drawback”. Drawback is a phenomenon that occurs about 15 - 30 minutes before the tsunami strikes land. Due to the increase in levels of the sea near the epicenter of the earthquake, the water level near the coast recedes to accommodate for this sudden increase in water levels. As a result, the water level decreases near the coast, thereby enabling the tidal gauges to prompt the CCC about this decrease being due to an impending tsunami. In normal tides, the water does not recede so far behind and hence this recession can only be due to a tsunami. This occurs only just before a tsunami strikes and thus can be used to evacuate the boats that are near the coast and the people who are immediately around the coast without any delay. These tidal gauges are connected to the land with the help of the same fiber optic cable network that is used to connect the transmitting buoys thereby saving the cost of establishing a new network.
c) Seismometers
They are the sensors used to detect the occurrence of the undersea earthquakes. More than 90% of the tsunamis are caused by undersea earthquakes. Hence, if an earthquake is detected with a suitable increase in pressure levels under the sea, then it is sufficient indication of a possible tsunami. There are 5 seismometers in the same grid as the buoys and pressure sensors distributed as 3 in the outer ring and 2 in the inner ring. Seismometers can detect earthquakes at distances of 2800-4200 km which is sufficient for our region of consideration. It has been observed that if the magnitude of the earthquake is found to be more than 7.5 on the Richter scale then it is sufficient to produce a destructive tsunami. These seismometers are also present on the sa me fiber optic network which serves as the backbone for all communications between the sensors and the CCC. Hence, all readings of the seismometers are directly relayed to the CCC. d) Airplane
The planes which are set to fly over the buoys that detect the tsunami such that their flight plan includes flying over the CCC as well are taken into consideration. Once the buoy detects a possible tsunami, it will beam out a message to the overhead plane using LOS, given the knowledge that the plane is scheduled to fly overhead. When the plane flies overhead, it will send out a beacon indicating its presence, and the buoy will then transmit the data that needs to be sent to the CCC, to the plane. When the plane flies overhead the CCC, it will transmit the message to the CCC using LOS again or it sends it to the satellite which will beam it to the CCC. This method may seem trivial but it adds the redundancy required to ensure there is not complete failure in the communication network built. e) Satellites
Satellites provide the final link in the communication between the sensors and the CCC. In case, the fiber optic cable network fails, then the satellite is the connecting block essential to carry the tsunami warnings to the CC C. Even when the fiber optic cable is working, in the event of a possible tsunami, the satellite takes images of the region and transmits it to the CCC for processing. The satellites used can be PanAmSat or IntelSat, which are available for telecommunications purposes. Images are a very effective method of determining the presence of a change in water levels due to tsunamis and are used widely today.
B) Notification System a) Central Command Center [CCC]
It is the main point of contact for all the sensors present on the Tsunami warning system network. It is located on the land and for the purposes of convenience of establishing warning communications in case of a tsunami, its position has been strategically selected to be in Northern California. This is centrally located on the west coast and it is easier to web out the communications message. The processing capability of this Central Command Center has to be massive and reliable because it is receiving huge amounts of data over time from t he sensors. Also, it might receive contradictory/ambiguous data from the multiple sensor networks and hence it needs to intelligently decipher the veracity of the data procured and take a decision based on that. It will consist of a central database to store data received. It will also have multiple routers based on the routing of alarm messages. Thus, once a decision is reached, the tsunami notification message is routed on the multiple networks [TV, Radio, Cellular network] and through conventional means [Sirens, Airplanes, Boats]. b) Cellular Phones • • • •
infrastructure already in place may not work if towers are damaged, such as in an earthquake automatic dialers cannot reach everyone who has a phone in the available time email messages are not likely to be received in the available time
c) Television, Radios • • •
infrastructure already in place will work best during the day and evening more information can be conveyed, such as pictures
d) Sirens • • • • •
can be heard up to half a mile away operate under self-sufficient power can be activated remotely (by radio frequency) or locally emit prerecorded alert message or siren most useful for warning people who are outdoors
e) Tone Alert Radios • • •
activated by radio frequencies (do not need to be already on to broadcast alert) short wave tone alert radios can be activated from a much further distance can emit prerecorded voice messages, sirens, live voice messages
4. TABLE OF REQUIREMENTS Feature of Network Buoy to CCC
Reliability
B/W
BER
Speed
Security
Range
High
Med
Low
Very High
High
Large
High
Med
Low
Ext. High
High
Medium
Low
Med
High
High
Med
Low
Medium
Low
Med
Sensors to CCC Buoy to Satellite Seismometer to CCC Buoy to Airplane
Dela y Low
Conn. Est. Yes
LOS
Small
Very Low
Yes
No
High
Large
Med
No
Yes
Very High
High
Large
Low
Yes
No
High
High
Mediu m
Med
No
Yes
No
5. ADDRESSING SCHEME
IP Addressing The addressing scheme will be based on IP addresses since it is a global standard of communication. Moreover, the addressing scheme is not complicated since the sensor networks are all independent and do not need to communicate with each other. They just need to communicate with the CCC. The addressing scheme decided is of the following type: •
1) Row 1 of Transmitting buoys (6 buoys) [Towards land] 192.168.1.11 to 192.168.1.16 2) Row 2 of Transmitting buoys (6 buoys) [Towards sea] 192.168.1.21 to 192.168.1.26 3) Row 1 of Seismometers (2 nos.) [Towards land] 192.170.1.11 to 192.170.1.12 4) Row 2 of Seismometers (3 nos.) [Towards sea] 192.170.1.21 to 192.170.1.23 5) Row 1 of Water Level Sensors [Towards Land] 200.125.1.1 to 200.125.1.12 6) Row 2 of Water Level Sensors [Towards sea] 200.125.2.1 to 200.125.2.12 •
Naming Scheme
1) Row 1 of Transmitting buoys (6 buoys) [Towards land] A1-A6 2) Row 2 of Transmitting buoys (6 buoys) [Towards sea] B1-B6 3) Row 1 of Seismometers (2 nos.) [Towards land] C1-C2 4) Row 2 of Seismometers (3 nos.) [Towards sea] D1-D3 5) Row 1 of Water Level Sensors [Towards Land] E1-E12 6) Row 2 of Water Level Sensors [Towards sea] F1-F12
6. DATA TRANSMISSION FORMATS 1. Tsunami Warning Message [4 bits] • • • •
00 => Keep Alive 01 => Sensor Faulty 10 => Buoy Faulty 11 => Tsunami Alert
2. Level of Tsunami Alert [4 bits] • • • •
00 => No Tsunami 01 => Level 1 Tsunami [ Wave Height = 1m – 4m] 10 => Level 2 Tsunami [ Wave Height = 4m – 12m] 11 => Level 3 Tsunami [ Wave Height = 12m – 100m]
3. IP Address [32 bits] •
As shown above
4. Buoy ID [8 bits] •
As shown above
5. Time of detection [16 bits] •
Military time e.g. 1900
6. Flag: Start of Frame identifier [8 bits] •
11000011
7. Coordinates of Central command Center [24 bits] •
E.g. 23(degrees) 63(minutes) N/W/S/E
8. Magnitude of Earthquake [8 bits] Richter Scale Magnitude e.g. 8.0 • 7. FRAME FORMATS 1. Buoy to Central Command Center
2. Buoy to Airplane
3. Seismometer to Central Command Center
4. Buoy to Satellite
5. Water Level Sensors to Central Command Center
6. Keep Alive Message [Seismometer/Buoy to Central Command Center]
8. ROUTING MECHANISM
The routing scheme used in this system is Static Routing. This is the most basic kind of routing technique because the source and destination addresses are fixed. In the Tsunami Warning System, it should be noted that none of the sensors need to communicate with each other. All the sensors need to communicate with the Central Command Center and vice versa. Hence all that is required is a mechanism to forward the message packet from the sensor to the Central Command Center and any sort of acknowledgment/ message from the CCC to the sensor. In case the sensor fails, it will not send keep alive messages which will be deciphered by the CCC and no more message exchange will take place between the dead sensor and the CCC. •
Keep Alive Messages
The Keep Alive signals will be used to determine whether the system is in working condition. This signal will be exchanged among the sensors and CCC every 2 seconds. In case of failure of a node, no Keep Alive signal will be sent from that node. This signal is continuously monitored by the routers. Failure of 5 Keep Alive signals to arrive will cause the sensor to be declared dead. An emergency signal will then be generated at the CCC announcing failure of the sensor and that action must be taken to rectify the error. The emergency signal will have a header specifying type of emergency. However failure of CCC can also occur after an earthquake or higher priority emergency. Hence failure of CCC will be taken to be equivalent to a serious emergency. CCC
failure due to technical reasons is not expected to occur often and hence such a scenario of a false alarm will not occur often. The message sent after a high priority emergency will be sent from the site of the CCC itself. 9. NOTIFICATION SYSTEM
Once the Tsunami warning reaches the land, it is the prerogative of the C entral Command Center to distribute it to the people who may be affected. The networks that will be used for this purpose have been described above. However, the exact warning message that will be transmitted is as shown below: 1. From the CCC to the Mobile networks • • • • • • • •
Time of detection [16 bits] Tsunami warning [4 bits] Location of earthquake [24 bits] Magnitude of Earthquake [8 bits] Expected disaster level of tsunami [4 bits] Range of devastation [16 bits] Time of expected arrival of tsunami [16 bits] Mobile networks that should broadcast message [32] where 32 is the length of IP address and n is the number of Mobile networks that need to be notified.
2. from CCC to TV Networks • • • • • • • • •
Time of detection [16 bits] Tsunami warning [4 bits] Location of earthquake [24 bits] Magnitude of Earthquake [8 bits] Expected disaster level of tsunami [8 bits] Range of devastation [16 bits] Time of expected arrival of tsunami [16 bits] Satellite images of affected region [ 10 MB]{10 images of 1MB each} Mobile networks that should broadcast message [32]
3. From CCC to Radio networks • • • • • • • •
Time of detection [16 bits] Tsunami warning [4 bits] Location of earthquake [ 24 bits] Magnitude of Earthquake [8 bits] Expected disaster level of tsunami [8 bits] Range of devastation [ 16 bits] Time of expected arrival of tsunami [16 bits] Mobile networks that should broadcast message[ 32]
4. from CCC to Tone Alert Radios • • • • •
Time of detection [16 bits] Tsunami warning [4 bits] Location of earthquake [24 bits] Magnitude of Earthquake [8 bits] Expected disaster level of tsunami [8 bits]
• • •
o
Range of devastation [16 bits] Time of expected arrival of tsunami [16 bits] Tone Alert Radios that should be notified [ 32 ]
How will notification take place?
When the tsunami warning is received by the CCC and it is corroborated by all the sensor networks in place, then it is time for the emergency message to be sent out. Since I am using the pre-existing networks in place, it is only required to send the warning message across to these backbone networks and then make sure that that they will convey the message across their networks without any delay. For example, the CCC will send all the parameters described above to all the TV networks along the Pacific coast, and only those TV networks that service regions that lie in the range of the devastation will broadcast the evacuation message. The TV broadcast stations / cell phone network base stations / radio stations will all be stored in the CCC so that the correct addresses can be selected, when the emergency message is being transmitted. This means that the CCC will send the message intelligently only to those broadcast stations along the west coast who lie in the danger zone. One method to send the message to these pre-established networks is to establish a coaxial cable line across the length of the coast and branch them to the individual broadcast stations of the mobile/TV/Radio networks[ which lie within 1000 miles of the coastline since 500 miles is the maximum recorded inland distance at which the tsunami affected]. The cost of setting up this coaxial cable line is estimated to cost about $0.5 million based on the length of the coast, cost of the coaxial cable and the number of broadcast stations that exist along the west coast. This is a leased line connection and it will only come in use in the event that a tsunami occurs. This is perfectly reliable means of communicating the message but it entails the cost of setting up a new network that will be used only occasionally. Another method to send the message is to use the Internet. The internet is an already existing network in place and makes use of twisted pair/coaxial cable/fiber optic cables. The main point is that the network is ready to be used. A point of consideration is that the CCC should have the contact IP’s/ contact addresses of all the broadcast stations [TV / Radio / Cell phone] stored in a database so that once the sensors give the warning, the CCC automatically will notify these networks over the internet. The cost of this network is negligible, with data security being an issue. However, if required a Virtual Private Network can be established between the CCC and the broadcast stations in order to ensure data protection. A trusted method of notification is the Siren and Tone Alert Radio. When the person in charge of the tone alert radio is notified of the emergency, he/she will activate the nearest located siren to warn the people close to the coast. There can be a distribution of sirens along the west coast such that there is one siren for every 20kms. Hence, we will need about 60 sirens for the length of the west coast. After the message has been sent to the major networks, the person in charge should recognize this as an emergency message and carry out standard procedures in case of an emergency. For e.g., if it is a TV network then current broadcast of existing channels should be stalled and the emergency message sent should be displayed on the network so that if people are watching T V then they immediately get the message. Similarly, in case of cell phone networks, a text message/automated call should be made to all subscribers notifying them of the impending disaster.
10. PROTOCOL STACK •
At Buoy
•
At CCC
•
At Seismometer
•
At Airplane
•
At notification systems
11. BANDWIDTH CALCULATIONS 1) For Backbone 1 [Fiber Optic Link] [Multimode fiber at 850nm]
6 Buoys to CCC [Keep Alive sent every 2 seconds] (80 * 6)/2 = 240 bps 3 Seismometers to CCC [Keep Alive sent every 2 seconds] (80*3)/2 = 120 bps 12 Sensors to CCC[ Keep Alive sent every second] (80*12) = 960 bps Total Bandwidth for Backbone 1 = 1320 bps = 1.32 kbps •
•
•
2) For Backbone 2 [Fiber Optic Link] [Multimode fiber at 850nm]
6 Buoys to CCC [Keep Alive sent every 2 seconds] (80 * 6)/2 = 240 bps 2 Seismometers to CCC [Keep Alive sent every 2 seconds] (80*2)/2 = 80 bps 12 Sensors to CCC[ Keep Alive sent every second] (80*12) = 960 bps Total Bandwidth for Backbone 2 = 1280 bps = 1.28 kbps •
•
•
3) For Satellite Link [At frequency of 11.6GHz (Frequency of PanAmSat)]
Emergency message to click images once tsunami is detected (88/0.1) = 880 bps Total Bandwidth for Satellite Link = 880bps •
4) For Buoy to Airplane [At frequency 8.9 GHz (Frequency at which airlines on West coast of USA have reception capability)]
Emergency message to be given to Central Command Center (96b/0.1) = 960 bps Total Bandwidth for Airplane Link = 960bps •
5) For Notification system [Co-axial cable] •
Since at a particular time coaxial cable can carry emergency message to every TV, cellular and radio tower on the west coast hence we consider maximum data transferred. Based on the information that the CCC will
transmit the information to 10 cellular, 10 T V and 10 radio towers whose coverage area will cover the entire west coast. The assumption is that the main providers are contacted and then they will forward the message on their complete network wherever they are located on the west coast. (30*(482)) = 1446bps [no picture message] (10*(10MB) / (3*60)) = 0.55Mbps [Picture Message] Total bandwidth of co-axial cable = 564.6 kbps 12. COST ANALYSIS •
Fiber Optic Cable Network
1) Length of Fiber optic cable for backbone (1, 2) 1500km+1500km=3000km 2) Connection of buoys to backbones [Cable length] and [Titanium mesh] 12 * 3km=36km 3) Total fiber optic cable length=3036km Cost of Fiber optic cable/km= $ Total Cost=$ 3036 * 2000 + $10000 = $ 6,082,000 •
Satellite Link
1) PanAmSat/IntelSat Yearly cost = $ 500,000 •
Transmitting buoy
1) Cost of 12 transmitting buoy modules [includes buoy, pressure sensor and acoustic link price] 12 * $250,000 = $ 3,000,000 2) Cost of maintaining 12 buoys 12 * $125,000 = $ 1,500,000 Seismometers •
1) Cost of 5 undersea seismometers 5 * $25000 = $125,000 Water Level Sensors 1) Cost of 24 water level sensors 24 * $3000 = $72,000 •
Notification System 1) Coaxial Cable extends from north to south [1200 kms] with branching occurring at the base stations [radio/TV/cellular] {considered to be an additional 1000km} 1300 * 387.5 = $ 503,750 2) Sirens 60 * $10000 = $600,000 Total Cost of System [Installation Cost]: $ 10,882,750[$ 10.882 Million] Maintainence Cost of System: $1,500,000+$500,000+$500000=$2,500,000 [$2.5 Million] / yr •
13. POSSIBLE PROBLEMS AND FUTURE WORK •
•
One of the major problems with this network is ambiguity of information. Multiple redundancies have been introduced to combat highly possible link failures. However, in the event they all run perfectly fine, and they give contradicting information then it is upto the discretion of the Central Command center to come up with an accurate prediction otherwise it could result in millions of dollars or millions of lives being lost. The German Aerospace Agency is researching the use of Zeppelins/Airships for Tsunami detection. It uses the concept of Doppler and Near Space Tsunami Radar [NESTRAD] and is effective over large distances. If the cost of the airship and the cost of fuel can be reduced in the future, this is a possible alternative to the usage of buoys since in idle periods it can be used to gather weather/ climatic information. 14. REFERENCES
Books and Papers:
1. Wireline Quality Underwater Wireless Communication Using High Speed Acoustic Modems- Xiaolong Yu, Ph.D. Linkquest Inc 2. Squeezing Performance From Your Ssb: Tips For Long-Distance Radios From Pacific Fishing, May 1997, By Terry Johnson, University Of Alaska Sea Grant, Marine Advisory Program 3. Study On New Low Cost Ocean Bottom Cabled Seismometers- Toshihiko Kanazawa, Hisashi Utada, Shinichi Sakai, Osamu Sano Hajime Shiobara, Masanao Shinohara, Yuichi Moiita, Tomoaki Yamada 4. Undersea Fiber Optic Networks: Past, Present, And Future by Frank W. Kerfoot, Member, Ieee, And William C. Marra 5. An Oceanographic Buoy With Interactive Satellite Communications by J.N. Shaumeyer, Carl C. Gaither Iii, Peter H. Young, John M. Borden, Erik Mollo-Christensen, And David Provost 6. Tsunami Detection Systems For International Requirements R. A. Lawson Science Applications International Corporation 7. An Integrated Approach To Improving Tsunami Warning And Mitigation by F. I. Gonzalez, E. N. Bernard, H. B. Milburn, V. V. Titov, H. 0. Mofjeld, M. C. Eble, J. C. Newman, R. A. Kamphaus, C. L. Hadden 8. Technology Developments In Real-Time Tsunami Measuring, Monitoring And Forecasting by Christian Meinig, Scott E. Stalin, Alex I. Nakamura, Frank González 9. Concept Design Of A Near-Space Radar For Tsunami Detection by Michele Galletti, Gerhard Krieger, Thomas Börner, Nicolas Marquart, Johannes Schultz-Stellenfleth Dlr – German Aerospace Agency Microwaves And Radar Institute 10. Tsunami Detectability Using Open-Ocean Bottom pressure Fluctuations by Adam Zielinski, Senior Member, IEEE, And Narendra K. Saxena 11. A Proposal Of Tsunami Warning System Using Area Mail Disaster Information Service On Mobile Phones by Yasuaki Teshirogi, Jun Sawamoto, Norihisa Segawa, Eiji Sugino 12. Waiting And Waiting For The Next Killer Wave- Philip E. Ross 13. U.S. Deep-Sea Tsunameter Network Fully Operational by Douglas Maxwell, Shannon Mcarthur, William Hansen, Richard Bouchard, Ian Sears, Jack Higgs And Mark Webster 14. Real Time Data Communication Through Indian Satellites For Buoys Operating In Indian Ocean Region And The Expansion Of Indian Moored Buoy Network by K. Premkumar 15. Computer Networks – A Systems Approach by Larry L. Peterson , Bruce S. Davie