DISAR (Differetial ISAR) DISAR is a ISAR data processig i which topographic patter is carefully removed. ISAR topography vs DISAR chage i topography DISAR Applicatios Subsidece (udergroud miig, oil/water extractio, tuel costructio, etc); Earthquakes (pre-, co- ad post-seismic seismic crustal deformatios ); Volcaoes; Ladslides; Lad settlemet; Dam deformatio; Soil moisture; etc Differetial ISAR for groud deformatio moitorig Appi Atarctica Sydey Buraki Fudig Idustry (Australia Coal Associatio Research Program) Australia Research Coucil (ARC-Discovery) Europea Space Agecy (ESA) ACRES (Australia Cetre for Remote Sesig) Geosciece Australia UNSW (FRG) ARC-Likage Iteratioal (with Hog Kog Polytechic) NICTA (Natioal Iformatio ad Commuicatio Techology of Australia) CRC-SI (CRC for Spatial Iformatio) Project 4.2 DISAR Approaches df = f Topo + f Defo + f Atmo + f Noise 2-pass DISAR (2 SAR images + exteral DEM) 3-pass DISAR (3 SAR images, Image 1+2 =>DEM, Image 1+3 => DISAR) 4-pass DISAR (4 SAR images, Image 1+2 =>DEM, Image 3+4 => DISAR) 2-pass DISAR DISAR techiques (Image 1 @ Image 2) - DEM 3-pass DISAR (Image 1 @ Image 3) - (Image 1 @ Image 2) 4-pass DISAR (Image 3 @ Image 4) - (Image 1 @ Image 2) Advaced (L-bad images) - (C-bad tadem images) multi-pass DISAR: sapshot > aimatio
2-pass Differetial ISAR (1) [Koike, 2001] Impact of DEM Quality o DISAR Results SAR processor: APP I-SAR: EarthView EV-ISAR Software Master tuig i yaw Atlatis Scietific Ic. (Caada) OS: MS-Widows NT simulated flat earth phase Iitial iterferogram Slave Orbit (flat earth) + Topo + Displacemet tuig i perpedicular baselie Β Differetial ISAR (1) [Koike, 2001] ISAR stable Iitial iterferogram flatte ig Case study: ( DEM) flatteed iterferogram Differetial phase correctio Subsidece moitorig i the Appi/Westcliff Appi/ Westcliff/Tower /Tower Collieries, southwest of Sydey Displacemet frige simulated flat earth phase simulated topo phase 0cm ear (UP) 0 +11.8cm 2π -11.8cm far (DOWN) 0cm D-ISAR Typical Pla View of Logwall Paels Subsidece Subsidece = surface movemets resultig from the creatio of sub-surface voids. Coal remaiig Miig Activities that result i subsidece. Metalliferous (Hard Rock) miig Udergroud Coal Miig Goaf Directio of miig Goaf Egieerig Activities that ca also result i subsidece. Remaiig chai pillars betwee logwall paels Logwall shearer Coal face Developmet headigs to create ew logwall paels Trechig Tuellig Solid coal Extracted logwall pael Curret logwall pael Future logwall pael Mai Headigs 2
Miig Subsidece Cross Sectio of a Typical Logwall Face Goaf Coal Seam Hydraulic roof supports Logwall shearer & coveyor Directio of miig Logwall shearer & coveyor Logwall Face Subsidece Modellig Hydraulic roof supports Udergroud Coal Miig ad Subsidece S u r f a c e Coal Seam Factors effectig Subsidece Depth of Cover Overlyig Strata Properties Seam Thickess Pael Width Chai Pillar Size Surface Topography The eed of subsidece moitorig i udergroud miig Legislatio Subsidece Predictio Maximise Coal Extractio Structural Desig Risk Maagemet Evirometal Moitorig
Survey Methods Two Curret Survey Dimesioal Surveys Provides base predictio data Capital equipmet costs miimum Ease of Processig ad Calculatios Highly accurate Digital Level, Surveyors Bad Total Statio Surveys Three Dimesioal Surveys Traverse Global Advatages Positioig System ( GPS) Survey Disadvatages BHP Billito llawarra Coal Illa wa rra Coal Carbo Ste el Ma te ria ls J auary 2 003 Labour itesive Time required ERS-2 SAR plaig for ISARERSISAR-GPS itegratio at the Tower Colliery LOcatio Locatio WEST CLI FF Appi 4 & 5 Shafts APPI N WOLLO NGO NG Holdigs Boudary N Cordeaux D ENDR OB IUM O 'B r ie s D rift W 2 4 Mied Are a Propos ed M iig Pit Tops 2-4: swath overlap 2&4-3: ascedig ad descedig orbits >> 3 images every 35 days 3 E Kem ira Valle y S 2.5 0 ELO UER A 2.5 5 Kilo me ter s C ompile d by Frak Cook Tec hica l & Ex te ra l Servi ces Por t Ke mb la Coa l Te rm ia l Reg io al Off ice C-bad radar coverage Bird s view of subsidece i the area Tows are white. Lakes are dark. A total of 18 MSDs!! MSDs 4
Mie workigs overlaid o aerial photo 931109_ 940321 (JERS-1) 132 days 931109_940321 (JERS(JERS-1, 132 days) 1 2 3 4 Subsidece i the Appi (BHPB groud survey, 2001) Subsidece + topographic residual: 34cm Zoom 1: 16cm Zoom 2: 26cm Zoom 3: 18cm Zoom 4: 17cm Profiles 5
Cotour map of subsidece Tower 3D View West Cliff Appi 3D View (LOS) JERS-1 Repeat-pass DISAR results Multi-pass DISAR results 6
Challeges Overlap betwee RS ad groud survey results Full scee DISAR processig (improved filterig ad phase uwrappig) Temporal ad spatial de-correlatio (PSISAR, ew satellites) Challege 1: Spatial ad temporal overlap Groud Surface Deformatio Profile Distace (m) Nov 93 Mar 94 Apr Ju 95 Sep 93 Nov 93 Mar Apr 95 Jul Nov 95 Nov 1986 Aug 93 Mar 94 Sep 94 Apr 95 Nov 95 Ja 96 95 Aug 93 Dec 93 Sep 94 Ju Aug 95 Apr 93 Feb 94 Ja 95 Jul 96 Groud Measuremet Data Ju 99 Subsidece (m) 2cm D-ISAR result shows a overlap with levellig lie D-ISAR result does ot have a overlap with levellig lie (m) DISAR Subsidece Profile 27Nov95~11Ja96, WestCliff Lie A Subsidece (cm) 2 1 0-1 -2-3 -4-5 -6-7 -8 0 20 40 60 80 100 Levelig Poit (A1~A98)
Challege 2: Full Scee DISAR Processig DISAR results for other mies
Groud movemet i 44 days Remote sesig vs groud survey Subsidece Profiles - DISAR v.s. Groud Survey 2.00 0.00-2.00 0 100 200 300 400 500 600 700 800 900 1000-4.00 Subsidece (cm) -6.00-8.00-10.00 Groud Survey (Sept 03~ Nov 93) Groud Survey (Aug 93 ~ Nov93) DiSAR (1993/09/26~1993/11/09) 900_3-12.00-14.00-16.00-18.00 Master: 26 September 1993; Slave: 9 November 1993; All acquired by the Japaese satellite JERS-1. Distace from the 1st levellig poit alog the 900 lie (m) Resolutio: +/- 1 cm! Subsidece (cm) 2 1 0-1 -2-3 -4-5 -6-7 -8 DISAR Subsidece Profile 27Nov95~11Ja96, WestCliff Lie A 0 20 40 60 80 100 Levelig Poit (A1~A98) Groud movemet i 24 hours ERS tadem DISAR Master: 29 October 1995, ERS- 1; Slave: 30 October 1995, ERS-2; Remarkable result of subsidece i 24 hours; A costellatio of ISAR satellites Resolutio: agai +/- 1 cm! ERS Tadem Subsidece profiles C- vs L-bad at Appi Resolutio: +/- 2 mm!
Buraki vs Appi (C-bad) How ca we use the image pairs with large spatial ad temporal baselies (> critical baselies)? Permaet scatterer ISAR (PSISAR) PS: discrete ad temporarily stable atural reflectors (smaller tha a resolutio cell), such as a water tak, a house. Advatages Permaet scatterer ISAR (PSISAR) suitability for wide area moitorig capability to provide deformatio data relative to sigle targets (very useful for a local descriptio of pheomea) millimetric precisio possibility to ivestigate past pheomea (exploitig the ESA ERS archive) Limitatios Need for PS Phase ambiguity (slow deformatio oly) Oe dimesioal displacemet oly