Pengantar Kontrol Kebisingan 2008( JILID I)

PENGANTAR KONTROL KEBISINGAN oleh Muhammad Dirhamsyah Jurusan Teknik Mesin Universitas Syiah Kuala 2008

Dasar Kontrol Kebisingan

Suara

Kebisingan

Terminologi Suara

Tekanan dan Energi Suara SPL = 20 log10 ( Prms/ Pref ), dB

SPW @ SWL = 10 log10 (W/Wref ), dB

Parameter Dasar Suara

Propagasi Suara

Tekanan Suara

Tekanan Suara

Tekanan Bunyi

Konversi Tekanan Bunyi (dB dan Pascal)

Aplikasi Tekanan Bunyi

dB dan Pascal

Persepsi Perubahan Peringkat Bunyi dalam dB

Persepsi dB dan Pascal secara grafik

Penggunaan tabel

Contoh sederhana

Jenis sumber suara

Anechoic dan Reverberant Enclosures

Ruang bertekanan (Pressure field)

Ruang Suara (Sound Field)

Indek Direktivitas (Directivity Index)

Penambahan Tekanan Suara di dinding

Dua sumber suara

Penambahan peringkat dB

Pengurangan Tingkat Kebisingan

Pengurangan Tingkat Kebisingan

Penambahan nilai dB

Kesimpulan • Tingkat tekanan suara dalam dB senilai 2 * 10‐5 Pascal

• Batasan kemampuan pendengara manusia sebesar 130dB

• Penambahan dan pengurangan nilai dB dapat menggunakan tabel atau rumus.

Analisa Frekuensi dan Panjang gelombang

Batasan Frekuensi dari beberapa sumber bunyi

Batasan Audibel (audible range)

Analisa Statistik

Analisa Statistik (2)

Panjang Gelombang

Panjang Gelombang dan Frekuensi

Difraksi Suara

Difraksi Suara

Refleksi Suara

Analisis Frekuensi

Bentuk gelombang dan frekuensi

Jenis suara dan sinyal kebisingan

Filter

Filter Bandpass dan Bandwidth

Jenis Filter dan skala frekuensi

Filter oktaf 

Filter oktaf 

1/1 dan 1/3

Spektogram

Persepsi Suara

Frekuensi Suara

Kawasan Audiotori

Persepsi suara

Kontur ~~ 40dB dan Beban‐A

Kontur ~~ untuk tone semula

Kurva Beban Frekuensi

Kalibrasi dan Pembebanan

Penggunaan Beban frekuensi

Analisis Serial

Analisis Paralel

Analyzer

Spektogram dan overall levels

(2)

Contoh analisis Wavelet (a) Time domain signal of two sine waves wave s with varying amplitude

(b) Fast Fourier transform of the signal

(c) Wavelet transform of the same signal

Kebisingan Trafik

Contoh Kebisingan Trafik Peringkat kebisingan trafik tergantung pada tiga faktor : (1)Volume trafik, (2)Kecepatan, (3)Jumlah kenderaan.

Katagori jalan Katagori  jalan dan jenis dan  jenis kenderaan

Aliran trafik dan peringkat suara

Aliran trafik dan aspek sosial

Akustik Bangunan

Sumber kebisingan Sumber kebisingan yang meningkat dalam bangunan: - Tetangga - Trafik - Industri Aplikasi akustik bangunan semakin meningkat dalam skop untuk mengatasi kontrol kebisingan dan gangguan bising dalam segala jenis bangunan.

Akustik bangunan Akustik bangunan – bangunan  – merupakan fenomena akustik dengan ruang tertutup seperti halnya ruangan atau bangunan. Ganggunan akustik yang terjadi berupa

•Refleksi •Penyerapan •Waktu gema •Waktu peredaman dan lain‐lain.

Refleksi suara • Sound can be reflected in a similar way to light

•

angle of incidence of  incidence = angle of reflection of  reflection

• Reflecting object must be at least the same size as the wavelength

Refleksi Penundaan panjang • In larger halls, ‘ray tracing’ can identify problematic echoes

• Echo = a reflection which arrives more than 50 ms after the direct sound

• Reflections can be prevented by covering the surfaces concerned with absorbent material or by making them into diffusing surfaces by means of a of  a convex shape.

Penyerapan suara Main types of absorbers: of  absorbers: Porous materials • consist materials such as fiberboard, mineral wools, insulation blankets, etc. • convert sound energy into heat. • more efficient at high than low frequencies • can be used in the form of space of  space absorbers • possible with the underside reflecting while the top is absorbent; can prevent long delayed sound at the same time, providing more reflection of sound of  sound to certain parts of the of  the audience.

Penyerapan Suara Membrane or panel absorbers

• good absorption characteristics in low frequency range (50 – (50  – 500 Hz)

• the approximate resonant frequency, f  f = f  = 60 / (md)1/2 Where m = mass of the of  the panel (kg/m2) d = depth of the of  the air space in m

Perilaku suara – suara  – Penyerapan suara Helmholtz atau cavity resonators Container dengan leher kecil terbuka dan ikut bergerak oleh resonansi udara dalam cavity udara  f  =

dmana

cr 

2 π  

⎡ ⎤ 2 π   ⎢ (2 l + π  r  )V  ⎥ ⎣ ⎦

c = kecepatan suara di udara r = radius leher l = panjang leher V = volume cavity

V 

l  2r 

Waktu gema (Reverberation Time) Sabine’s formula T  =

0 . 16 V   A

Dimana T = waktu gema, detik V= volume ruang, m3 A= penyerapan ruang, m2 Dan 0.16 merupakan suatau empirik konstan, detik/m Waktu gema, T60 adalah lamanya suara hilang sebesar 60 dB(A).

Reverberation Time Sabine’s formula Jika luas permukaan = S, maka rata‐rata koefisien penyerapan (average absorption coefficient), ά ά =  A S

Maka, T  =

0 .16V  S α 

Penyerapan bunyi Pada banyak  jenis menggunakan rumus, α 

=

1 S

contoh

∑S

yang

digunakan

i α  i

i

Jika permukaan ruang digunakan dengan contoh yang berbeda, maka,  N 

∑ α 

=

S

i α  i

i =1  N 

∑ i =1

S

i

Material Penyerap Bunyi • Dua metoda untuk mengukur koefisien penyerapan : • Metoda ruang gema (Reverberation chamber) • Metoda tabung impedansi (Impedance tube) • Metoda Reverberation chamber (ISO R354‐1985, ASTM C423‐1984 and AS 1045‐1988) Koefisien

ruang, R  =

S

α 

1 − α 

Teknik Pengujian Akustik Impedance Tube Karakteristik akustik dari panel diperoleh dengan menggunakan metoda impedance tube berdasarkan ISO 10534 (II).

Metoda Reverberation Chamber Sα  =

55.25V  ⎡ 1 c

(S '−S ) ⎤

⎢ − ⎥(m ) ⎣T 60 S '−T '60 ⎦ 2

S’ = Luas permukaan total termasuk luas sampel T’60= Waktu gema Reverberation tanpa sampel T60 = Waktu gema (Reverberation) (Reverberation) dengan sampel S = Luas permukaan sampel V = volume ruang α = Koefisien penyerapan Sabine (absorption

Metoda Reverberation Chamber

Pengukuran Reverberation Time Dalam ruang gema (reverberation room): Lp, dB 60 dB

T60

t

Pada ruang normal (dengan ‐ high background noise): Lp, dB

60 dB

Background noise

t T

Pengukuran Reverberation Time • •

Pengukuran dapat digunakan dengan metoda dibawah.

• •

Perekaman di konversikan ke pengukuran tekanan bunyi dalam dB.

Sebuah mikrofon dihubungkan ke  frequency analyser   frequency  analyser  yang terhubung pada perekaman suara (level recorder  ). level  recorder ). Peralatan berbasiskan microprocessor‐based modern dapat menghasilkan grafik yang dapat langsung mengukur waktu gema (reverberation time). Sound source Frequency analyser Level recorder microphone

Jenis Reverberation Time pada Ruang 3RD OCTAVE BANDWIDTH CENTRE FREQ. (Hz)

REVERBERATION TIME (s)

100

1.55

125

1.60

160

1.45

200

1.30

250

1.20

315

1.05

400

1.05

500

1.00

630

1.10

800

1.00

1000

0.90

1250

1.05

1600

1.05

2000

1.05

2500

1.00

3150

0.95

Bangunan Akustik Apa yang harus diukur?  Suara latar

(Background Noise)  Waktu gema

(Reverberation Time)  Penyerapan Suara

(Sound Absorption)  Isolasi suara

“Airborne” “Airborne” dan impak (airborne and Impact sound insulation)

Airborne dan Impact Indek Pengurangan Suara (Sound Reduction Index) atau kehilangan transmisi suara (Sound Transmission Loss) W4

Room 1 W1

W3 W2 Room 2 Dissipated as heat

Prinsip transmisi suara melalui dinding : W3 dan W4 merepresentasikan transmisi flanking sound ke komponen dari struktur; W3 yang selalunya di radiasikan ke ruang 2, W4 yang tidak termasuk.

Airborne dan Impact Sound insulation Indek Reduksi Suara (Sound Reduction Index) atau Kehilangan Transmisi suara (Sound Transmission Loss) Koefisien transmisi suara, τ τ  

=

W 2 W 1

Indek reduksi suara, R

 R = 10 log

1 τ  

dB

Pengukuran Reduksi Suara • Metoda untuk mengukur insulasi dinyatakan secara standar nasional dan internasional. • Metoda yang umumnya digunakan untuk mencari insulasi suara airborne adalah metoda dua‐ruang (the two‐room method).

 R =  L1 −  L 2 + 10 log

S  A

dB

L1 = Peringkat tekanan suara (sound pressure level) pada sumber suara dalam ruang (dB) L2 = Peringkat tekanan suara pada ruang penerima (dB) S = Luas spesimen pengujian A = Luas penyerapan suara ekivalen

Methoda dua ruang – ruang  – Uji Lab.

Membandingkan hasil dengan keperluan – keperluan  – Isolasi suara Single Figure Indices • ISO 717‐1982 menggambarkan suatu metoda yang mempunyai gambaran tunggal dari airborne dan kurva insulasi impak suara yang di ukur berdasarkan ISO 140.

• Indek Reduksi Pembebanan Puncak suara “Weighted   Apparent Sound   Apparent  Sound Reduction Reduction Index, R’ w 

Membandingkan hasil dengan keperluan – keperluan  – Isolasi suara • Weighted Normalized  Weighted  Normalized Impact  Impact Sound  Sound Pressure Pressure Level, L’ n,w 

Survey Akustik Bangunan

Insulation – Insulation  – Standar Akustik Bangunan Raw insulation, D

French standard NF NF S 31-057

 Normalise  Normalised d insulatio insulation, n, DnT  Normalise  Normalised d insulation insulation in dBA, dBA, DnAT Raw insulation D = L1-L2

International Standard ISO 140-4

 Norm  Normali alised sed acoust acoustic ic insulati insulation on Dn =  Normalised  Normalised acoustic acoustic insulation Dn,T= Dn,T= Weighted Weighted normalised normalised acoustic acoustic insulation Dn,w

International standard ISO 717-1

Weighted Weighted normalised normalised acoustic acoustic insulation Dn,T,w Sound reduction index R

International standard ISO 140-3 (NF EN 140-3)

Apparent sound reduction index R’

International standard ISO 140-4 (NF EN 140-4)

Weighted sound reduction index RW

International Standard ISO 717-1 (NF EN 717-1)

Apparent weighted sound reduction index R’w

Bunyi Impact Impact Impact normalised normalised sound pressure pressure level level LnT Impact Impact normali normalised sed sound pressure pressure level level in dBA LnAT

Impact Impact normalised normalised sound pressure pressure level level Ln Impact Impact normalised normalised sound pressure pressure level level L’n

French standard NF S 31057

International standard ISO 140-6 et ISO 140-7

Impact Impact standardised standardised sound sound pressure level L’nT

Impact normalised normalised weighted sound sound pressure level Ln,w Impact normalised normalised weighted sound sound pressure level L’n,w Impact standard weighted sound pressure level L’nT,w

International standard ISO 717-2

Kebisingan Peralatan Equipment noise normalised level LeT

French standard  NF S 31-057

Absorption Absorption coefficient ∝s

International standard ISO 354 (NF EN 20354)

Weighted absorption index ∝w

International standard ISO 11654 (NF EN 11654)

 APPLICATIONS OF BUILDING OF  BUILDING  ACOUSTICS

• Impact test • Glazing test • Absorption test

IMPACT TEST  IMPACT  TEST  Tapping Machine

Chadwick Roof 

Microphone Rotating Boom

Speaker

Overall Set‐up of the of  the Impact Test

IMPACT TEST  IMPACT  TEST – – METHODOLOGY  • Main purpose : to find a single‐number quantity used for defining the impact sound insulation of a of  a roof structure roof  structure as stipulated in ISO 717‐2 Standard Procedures.

• Weighted Normalised Weighted  Normalised Impact Sound  Impact  Sound Pressure Pressure Level  denoted by the symbol, L’n,w

CALIBRATION

BACKGROUND NOISE LEVEL MEASUREMENT

CALCULATION OF L’n,w

REVERBERATION TIME OF RECEIVING ROOM MEASUREMENT

SOUND PRESSURE LEVEL INSIDE THE TEST ROOM MEASUREMENT

IMPACT TEST  IMPACT  TEST  ‐ RESULTS of  interest • In general within the frequency range of interest (From 100Hz up to 3150Hz) the difference between the received sound pressure levels from the impact test and the background noise levels are above 20dB. Normal alis ised ed Impa Impact  ct  • The calculated Weighted  Norm Sound Pressure Sound  Pressure Level , L n′ ,W = 48dB.

GLAZING TEST  4.41m

5.30m 5.48m

RECEIVING ROOM

6.28m

Opening for Acoustic Testing 1m2

Acoustic Door

TRANSMITTING ROOM Microphone 6.5m 6.0m Speaker 5.5m

GLAZING TEST 

TRANSMITTING ROOM

Glazing Test Sample

RECEIVING ROOM

Cross section of the of  the acoustic test rooms

GLAZING TEST 

Sample view from the transmitting room.

 ABSORPTION TEST   ABSORPTION  TEST  • Location : Acoustic Laboratory, UKM • Reverberation room capacity volume = 171 m3 : 10 m2 wall panel • Sample test

5.50 m

5.48m

4.41 m

6.28m 6. 32m 5.30 m

Opening for Acoustic Testing 1m2

4.58 m

5.33 m Acoustic Door

 ABSORPTION TEST   ABSORPTION  TEST 

microphone

speake r Test sample

Cross section of the of  the reverberation room

 ABSORPTION TEST   ABSORPTION  TEST 

Reverberation room

 ABSORPTION TEST   ABSORPTION  TEST  ‐ RESULTS • For the wall panel sample,  Alpha Sabine , α = 0.65

 ABSORPTION TEST   ABSORPTION  TEST  ‐ RESULTS

Korelasi dengan Vibrasi

Pengukuran Getaran Many installations in modern building, eg. Lifts and washing machine, produce both noise and vibration. Noise measurements must therefore be complemented by vibration measurements.

• Vibration Isolation Measurements

Pengukuran Getaran • Measuring the Loss Factor of a of  a Partition the Loss Factor, η calculated from , f = f  = centre frequency of the of  the 1/3 octave band T = corresponding reverberation time

Rantai Pengukuran

Analisa Frekuensi

Analisa Frekuensi

Spektrum Frekuensi

Spektrum Frekuensi

Representasi Data

Skala Linear dan Logaritmik

Skala Linear dan Logaritmik

Skala Frekuensi Linear dan Logaritmik

Filter Bandpass dan Bandwidth

Filter Bandpass dan Bandwidth

Jenis Filter

Filter Bandwidth konstan

Filter Persentasi Bandwidth Konstan

Skala Frekuensi

Pemilihan Bandwidth

Analisa Frekuensi

Skala Amplitudo

Skala dB

Transmisi Getaran

Kondisi aktual getaran

Parameter Vibtrasi

Pemilihan parameter

Detektor / purata

Purata Waktu

Analisis sistem vs sinyal

Akselerometer

Verifikasi eksperimen

Pengujian‐pengujian

Pengujian‐pengujian

Pengujian‐pengujian

Pengujian‐pengujian

Pengujian‐pengujian

Pengujian‐pengujian

Pengujian‐pengujian

Pengujian‐pengujian

Pengujian‐pengujian

Pengujian‐pengujian

Pengujian‐pengujian

Pengujian‐pengujian

Pengujian‐pengujian

Bantalan (Bearing – (Bearing  – outer)

Lingkungan

Melbourne Airport's Environmental Management System (EMS)

was accredited to world's best practice practice standard, ISO 14001 in in June 2004 - making it the first airport in Australia to receive this internationally-recognis internationally-recognised ed accreditation.

Airport Noise Management There are four main mechanisms that are used to manage and minimise the noise effects effects generated generated by aircraft aircraft approaching approaching or departing departing from Melbourne Airport. • Control of Airspace Airservices Australia is responsible for management and control of the flight paths used by aircraft approaching and departing from Melbourne Airport. • Monitoring of Noise Complaints Noise complaints are received by Airservices on its 24-hour number 1300-302240. • Noise Abatement Committee The Committee's role is to review the impact of aircraft noise exposure on the surrounding community and in a consultative manner, make recommendations to minimise minimise the effect of aircraft aircraft noise. noise. The Committee Committee meets on a quarterly quarterly basis. • Land use Controls The controls are mainly concerned with the development of residential land and are administered by the local council's statutory planning departments.

Trafik Jalan dan Rel

Trafik Udara

Studi

Pemantauan Kondisi Pemesinan

Pemantauan Kondisi Mesin • Sinyal kerusakan di tampilkan pada spektogram adalah implusif 

• Prosedur perawatan perlu di

NC MillingMachine

laksanakan agar lebih efisien

CNC Lathe

Lathe Machine  G  e  a r  B   o x 

Small-Drilling Machine

Contoh analisis sinyal dengan gangguan impak (a) Terjadi impuls yang mengganggu sinyal sinus

(b) Hasil dengan Fast Fourier Transform

(c) Menggunakan wavelet transform

Evaluasi Performansi Mesin

Evaluasi

Experiment setup

Raw material Drilling operation

Drilling performance

Sumber bunyi pada kenderaan

Sistem Pemantauan Dini Tsunami

PETA RENCANA SISTEM INA‐BUOY PENGEMBANGAN & KEREKAYASAAN PRODUCTS

2006

2007

2008

2009

SURFACE BUOY

RE ENGINEERED

INDIGINEOUS

IMPROVED VEHICLE

NEW CONCEPT, MULTI PURPOSE

OCEAN BOTTOM UNIT

SIMPLE STRUCTURE

SIMPLE DESIGN, IMPROVE MATERIAL

NEW APPROACH TO HOUSE PAYLOAD AND DEPLOYMENT

NEW CONCEPT, MULTI PURPOSE SCENTIFIC PLATFORM

ACOUSTIC LINK

SINGLE CHANNEL OMNI DIRECTIONAL

DUAL CHANNEL, REPEATER LINK, DIRECTIONAL

DUAL CHANNEL MULTI ACCESS

FULL REDUNDANT, MULTI ACCESS, HI RELIABILITY LINK

SATELLITE LINK , WIRELESS LINK

SINGLE CHANNEL

TWO SYSTEM, HALF FULL REDUNDANT

ONE SYSTEM, FULL REDUNDANT , MOBILE

INTEGRATED SYSTEM, FULL REDUNDANT, HIGH MOBILITY

SENSORY SYSTEM & PROCESSING

PRESURE SENSOR SINGLE PROCESSING

MULTIPLE SENSORS DUAL PROCESSING

TSUNAMI AND OTHER SCIENTIFIC DUAL PROCESSING

INTELLIGENT SENSORY SYSTEM NETWORK, INTELLIGENT PROCESSING

READ DOWN STATION

SIMPLE RECEPTION & DISPLAY & MONITORING

MULTI DISPLAY , MULTI SERVERS, NETWORK READY

MULTI DISPLAY, SOFT SWITCHABLE MONITORING, NETWORK CAPABLE

INTERNATIONALLY CAPABLE MONITORING, FULL NETWORK CAPABLE DATA BUOY CENTER

DATA NETWORKING

NA

BPPT LAN, AUTHORIZE AND PUBLIC ACCESS

NATIONAL & REGIONAL NETWORK DATA POSTING AND ACCESS

INTERNATIONAL INTERNETWORKING, INDONESIA DATA BUOY CENTER

SYSTEM REQUIREMENTS SYSTEM REQUIREMENT

PERFORMANCE PARTICULARS

systems meet a number of data stream requirements that are essential to an operational tsunami forecast system:

Characteristic

Specification

Reliability and and data return ratio: Maximum de deployment de depth: Minimum deployment duration: Operating Condition Conditions: s:

Greater than 80% 6000 m Greater than 1 year Beaufort 9 (survive Beaufort 11) Greater than 2 years Greater than 4 yrs

1. Measurement: 2. Accuracy: 3. Sampling: 4. Processing: 5. Delivery:

tsunami amplitude time series 0.5 cm or less 1 min or less 2 min or less 5 min or less

Maintenance interval, buoy: Maintenance interval, tsunameter Sampling interval, internal record: 15 sec Sampling interval, event reports: 15 and 60 sec Sampling interval, tidal reports: 15 min Measurement sensitivity: Less than 1 mm in 6000 m; 2 10–7 Tsunami data report trigger Automatically by tsunami detection algorithm; on demand by warning center request Reporting delay: Less than 3 min Maximum status report interval: Less than 6 hrs

Surface Buoy, Generasi‐1 Krakatau INMARSAT SATCOM METEO SENSOR FLASH LAMP RADAR REFLECTOR INSTRUMENTATION BAY • ACOUSTIC MODEM • INMARSAT T‐BOX • PROCESSING UNIT • AWS DATA LOGGER • BATTERY ACOUSTIC TRANSDUCER

Ocean Bottom Unit (OBU) Acoustic modem Releaser Battery

CPU Pressure sensor

Nylon Rope 1”, 220 m long, Sachel 1 ”, ” Nylon Rope 1”, 220 m long, Sachel 1 ”, ” Nylon Rope 1”, 220 m long, Sachel 1 ”, ” Nylon Rope 1”, 220 m long, Sachel 1 ”, ” Nylon Rope 1”, 220 m long

MOORING CONFIGURATION INDONESIA TEWS

Surface Buoy

Ring ¾”, Sachel ¾ Ring ¾”, Sachel ¾ Ring ¾”, Sachel ¾ Ring ¾”, Sachel ¾

Sachel Sachel 1 ”, Ring Ring ¾”, Sachel Sachel ¾ ” Floaters Bentos, 4 balls @25kg buoyancy Sachel Sachel ¾ ”, Ring ¾”, ¾”, Sachel Sachel 1” Nylon Rope 1”, 220 220 m long, Sachel 1 ”, Ring ¾”, Sachel ¾ ” Nylon Rope 1”, 220 220 m long, Sachel 1 ”, Ring ¾”, Sachel ¾ ” Nylon Rope 1”, 170 m long

Sachel Sachel 1.5”, 1.5”, Ring ¾” PWB Chain ½”, 10m long Sachel Sachel Crosby Crosby ½” Swivel Eye + Eye 5/8”, 5 t Sachel Sachel Crosby Crosby ½”

Sachel Sachel 1 ”, Ring ¾”, ¾”, Sachel Sachel ¾ ”

Floaters Bentos, 8 balls @25kg buoyancy Steel Wire, ½”, 250 m long

Sachel Sachel ¾ ”, Ring Ring ¾”, ¾”, Sach Sachel el ¾ ” Swivel Eye+ Eye,

Sachel Sachel ½”, Ring Ring ¾”, Sachel Sachel ½”

Sachel Sachel ¾ ”, Ring Ring ¾”, ¾”, Sach Sachel el ¾ ”

Floaters Bentos, 8 balls @25kg buoyancy Sachel Sachel ½”, Ring Ring ¾”, Sachel Sachel ½” Steel Wire, ½”, 250 m long

5t

Acoustic Releaser MORS (40kg) Chain PWB, ¾”, 10 m long

Ring ¾”, Sachel ¾ ” Chain PWB, ¾”, 10 m long

Sachel Sachel ½”, Ring Ring ¾”, ¾”, Sachel Sachel ½” Floaters Bentos, 8 balls @25kg buoyancy

Parachute with 7m lines (opt) Sachel 1” Sinker ( Steel covered Concrete) 3,2 t

Sachel Sachel ½”, Ring Ring ¾”, ¾”, Sachel Sachel ½”

DATA LINK BUOY – BUOY  – RDS, SAAT INI

Surface Buoy

INMARSAT LES

VPN or Internet

BPPT GD‐1 LT.20

Geodetic measurement: how it works

Gempabumi

zona zon a pat pata ahan

titi ti tik k kont k ontrol rol

Kerak Bumi Sebelum Regangan

Gaya Elastis Mencapai Limit

[email protected]

Pelepasan ‘stress’

Gelombang Sei Sei smik 

Precise Real-Time GPS: Requirements l

Reliable communication channels (dedicated lines, spreadspectrum radio, wireless Internet, satellite, FM sub-carriers, …)

CONTINUOUS (PERMANENT) GPS Continuously recording GPS receivers permanently installed Give positions instantly Provide significantly more precise data: No errors in setting up equipment and reoccupying sites Very stable monuments Many more positions to constrain time series

Can observe transient signals such as due to earthquake

Referensi

BRUEL AND KJAER BA766611, BA766911 , BA767612, BV0052, BV0053, BV0054, BV0055, TP213, TP216

[email protected] INA‐BUOY SYSTEM, ENG. & DEV.  – BPPT PROF JAILANI M NOOR HAND‐OUT