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Coral Bleaching and Satellite Remote Sensing

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Page 1: CrockettJohnson RS Presentation · CrockettJohnson_ RS_Presentation.pptx Author: David Sandwell Created Date: 6/2/2016 9:38:05 PM

Coral  Bleaching  and  Satellite  Remote  Sensing  

Page 2: CrockettJohnson RS Presentation · CrockettJohnson_ RS_Presentation.pptx Author: David Sandwell Created Date: 6/2/2016 9:38:05 PM

Economic  Value  

•  Coral  reefs  hold  $10  trillion  in  value  and  contribute  $30  billion  to  global  GPD  annually  

•   Tourism  and  RecreaCon:  $9.6  billion  •  Fisheries:  $5.7  billion  •  Coastal  ProtecCon:  $9.0  billion  •  Biodiversity:  $5.6  billion  •  Developing  communiCes  depend  on  reefs  for  sustenance  and  survival  

Page 3: CrockettJohnson RS Presentation · CrockettJohnson_ RS_Presentation.pptx Author: David Sandwell Created Date: 6/2/2016 9:38:05 PM

Coral  Bleaching  •  Rising  ocean  temperatures,  

increasing  ocean  acidity,  and  polluCon  all  impact  coral  health  

•  Corals  expel  symbioCc  algae  when  under  environmental  stress  

•  Coral  bleaching  can  cause  enCre  reef  ecosystems  to  collapse  

•  Cost  to  global  economy:                    $20  billion  to  $84  billion  

Page 4: CrockettJohnson RS Presentation · CrockettJohnson_ RS_Presentation.pptx Author: David Sandwell Created Date: 6/2/2016 9:38:05 PM

Satellite  Remote  Sensing    and  Coral  Bleaching  •  Successes  in  mapping  reef  systems  and  monitoring  ocean  condiCons  

•  NOAA  Coral  Reef  Watch  

 

Page 5: CrockettJohnson RS Presentation · CrockettJohnson_ RS_Presentation.pptx Author: David Sandwell Created Date: 6/2/2016 9:38:05 PM

Mystery  Satellite  

•  60cm  x  60cm  x  80cm  •  Weighs  less  than  100kg  •  Achieves  spaCal  resoluCon  of  80cm  •  1.1  meter  video  resoluCon  at  30  frames  

per  second  •  Costs  less  than  $50  million  •  WorldView-­‐3  weighs  2,800  kg  and  cost  

$650  million  •  Two  spacecraY  currently  in  orbit  •  Revisit  Time:  3-­‐5  days    

Page 6: CrockettJohnson RS Presentation · CrockettJohnson_ RS_Presentation.pptx Author: David Sandwell Created Date: 6/2/2016 9:38:05 PM

Mystery  ConstellaCon  

•  Within  a  few  years,  firm  will  launch  at  least  12  more  satellites  

•  All  craY  to  follow  same  sun-­‐synchronous  orbit  between  500-­‐600km  alCtude  

•  This  constellaCon  will  achieve  sub-­‐daily  revisit  Cmes  for  every  spot  on  Earth  

•  Unprecedented  spaCal  and  temporal  resoluCon  

Page 7: CrockettJohnson RS Presentation · CrockettJohnson_ RS_Presentation.pptx Author: David Sandwell Created Date: 6/2/2016 9:38:05 PM

Image  Processing  •   35  cm  aperture  has  naCve  resoluCon  of  1.4  m  •  Satellite  captures  mulCple  images  with  an  average  exposure  Cme  around  

400ms    •  “Super-­‐resoluCon”  algorithm  determines  homographies  between  

consecuCve  frames    •  Stacking  these  frames  averages  out  the  noise  and  boosts  the  SNR.  •  All  processing  is  ground  based    

Page 8: CrockettJohnson RS Presentation · CrockettJohnson_ RS_Presentation.pptx Author: David Sandwell Created Date: 6/2/2016 9:38:05 PM

Maneuverability  

•  These  satellites  feature  a  propulsion  module  •  Frequent  slewing  will  cause  slight  period  variaCons  for  each  satellite  

•  ConstellaCon  spacing  or  “staConkeeping”  •  LEO  Environment  and  Collision  Avoidance  

Page 9: CrockettJohnson RS Presentation · CrockettJohnson_ RS_Presentation.pptx Author: David Sandwell Created Date: 6/2/2016 9:38:05 PM

Scheduling  

•  EssenCal  to  avoid  redundant  imagery  and  decreased  yield  •  w  =  overall  weight  •   v  =  business  value  •  a  =  number  of  previous  imaging  abempts  •  r=  revisit  potenCal  •  n  =  off-­‐nadir  angle  •  f  =  cloud-­‐cover  forecast  

𝑤=𝑣(1−∑𝑎=1↑𝑁▒2↑−𝑎 )(1+ 4−𝑟/𝑟  )(1.2-­‐0.013n)(1-­‐0.5f)  

Page 10: CrockettJohnson RS Presentation · CrockettJohnson_ RS_Presentation.pptx Author: David Sandwell Created Date: 6/2/2016 9:38:05 PM
Page 11: CrockettJohnson RS Presentation · CrockettJohnson_ RS_Presentation.pptx Author: David Sandwell Created Date: 6/2/2016 9:38:05 PM
Page 12: CrockettJohnson RS Presentation · CrockettJohnson_ RS_Presentation.pptx Author: David Sandwell Created Date: 6/2/2016 9:38:05 PM