Monitoring of the Arctic by Remote Sensing

Transcription

1 Monitoring of the Arctic by Remote Sensing Arctic Conference: Challenges And Opportunities For Norway 10 May 2012, Oslo Militære Samfund Stian Solbø, Rune Storvold and Harald Johnsen Northern Research Ins.tute (NORUT) 1

2 The arctic The importance of the Arc=c region is increasing due to its enormous resources in fisheries, and its poten=al for large resources of minerals and oil and gas. Total popula=on: approx. 2millon 2

3 New shipping possibilities Further, the declining polar ice cap, is opening the poten=al for efficient shipping routes between Asia and Europe/America. 3

4 Remote sensing of the Arctic Usually carried out using polar orbi=ng satellites At high la=tudes several daily visits are possible Ac=ve microwave sensors (SAR) are usually preferred for opera=onal services due to all weather capability and independence of daylight 4

5 Examples on (Arctic) monitoring using satellite remote sensing Off-shore Sea ice extent and classification Ship detection and monitoring Oil spill detection Ocean wind, wave and current measurements On-shore Landslide monitoring Snow covered area mapping Glacier monitoring Permafrost active layer displacement measurements 5

6 Sea ice extent and classification SAR used for fine scale sea ice details Operational service eg. at met.no Providing new sea ice maps daily Manual process. Trained expert operators are required 6

7 Sea ice extent and classification 7

8 Sea ice extent and classification 8

9 R&D on Sea Ice classification Fully polarimetric SAR provide sufficient information for roust automated classification Credits: Dr. Anthony Doulgeris, University of Tromsø 9

10 Polarimetric SAR Sea-Ice Properties Classification Roughness FYI, MYI Ice fraction Wet or dry snow cover Coupled with Cryosat II we can also get ice thickness 10

11 Ocean wind, wave and current measurements The SAR signal from the ocean surface depends on the wind field, surface currents and ocean waves Algorithms exists to separate the different terms The EnviSAT wave mode processor was developed at Norut Improved wave mode processor in progress for the ESA Sentinel 1 satellite 11

12 Ocean wind, wave and current measurements The SAR signal from the ocean surface depends on the wind field, surface currents and ocean waves Algorithms exists to separate the different terms The EnviSAT wave mode processor was developed at Norut Improved wave mode processor in progress for the ESA Sentinel 1 satellite New real time use : coastal monitoring (erosion, sediment transport, marine activity planning, pollutant dispersion...) direct use for very accurate short term forecast or assimilation in physical and biological regional shelf models assimilation in global/regional NWP models 11

13 Page 12

14 Basic SAR ocean measurables Ocean measurables from single SAR: Radar Cross Section (NRCS) (from calibrated image intensity) sea surface wind speed SAR Image Spectra (from spatial modulation in image) Ocean wave spectra Doppler Centroide Frequency (from Doppler (Azimuth) spectrum) Ocean surface current (radial motion of surface scatterer) Page 12

15 Basic SAR ocean measurables Ocean measurables from single SAR: Radar Cross Section (NRCS) (from calibrated image intensity) sea surface wind speed SAR Image Spectra (from spatial modulation in image) Ocean wave spectra Doppler Centroide Frequency (from Doppler (Azimuth) spectrum) Ocean surface current (radial motion of surface scatterer) Additional observables from constellation of SARs: Interferometric Phase radial surface motion of scatterer (surface current/winds) Page 12

16 Continental Shelf Effect Wave Field, Resolu=on 5kmx5km, Central European Atlan=c Norut UiT Seminar, 16 March 2012 Page 13

17 Continental Shelf Effect Wave Field, Resolu=on 5kmx5km, Central European Atlan=c Norut UiT Seminar, 16 March 2012 Page 13

18 Applica=on in wave climatology. NB! WM gives about imageves globally each month. Norut UiT Seminar, 16 March 2012 Page 14

19 SAR measured Radial Velocity or Doppler Predicted Radial Velocity (or Doppler) from wind field Residual velocities Surface current? SAR observable Norut UiT Seminar, 16 March 2012 User based off-line processing Page 15

20 SAR measured Radial Velocity or Doppler Ocean Surface Current Predicted Radial Velocity (or Doppler) from wind field Residual velocities Surface current? SAR observable Norut UiT Seminar, 16 March 2012 User based off-line processing Page 15

21 Norut UiT Seminar, 16 March 2012 Page 16

22 Multiple Images - Mean Radial Velocity Norut UiT Seminar, 16 March 2012 Page 16

23 Ship detection and monitoring SAR is an excellent tool for ship detection Operational services are usually semiautomated 17

24 Oil spill detection SAR is used in operational oil spill detection Depends on right wind/wave state False positives from natural films (algae) Trained operators are required

25 Syntethic Aperture Radar (SAR) Operational use today: Used to detect oil in open water Used to fine scale sea ice classification 19

26 The Arctic challenge: Detecting Oil Spill in Ice 20

27 Why does this matter Increased shipping activity and oil and gas exploration in the arctic increase the risk of oil spills in ice infested waters Detection of oil in ice is difficult and both detection and clean up approach depend on ice and oil properties Starting to draw attention by industry, stakeholders and the scientific community 21

28 GPR Due to the large opening angle of the antenna, flights must be flown at very low altitudes. SIRAL SAR Interferometric Radar Altimeter Reduce footprint, Increase flight altitude. Used on CryoSat From Sintef s study of Oil in Ice 22

29 Optical Detection Oil Spectral response Praks et al, 2004, HUT, Finland 23

30 Optical Imagery Modis Pixelsize is 250 meters, Airborne data sub-meter. Praks et al, 2004, HUT, Finland 24

31 Optical Imagery Simple image processing, If Rnir > Rgreen => oil present. Praks et al, 2004, HUT, Finland 25

32 Limitations with satellite remote sensing Coarse resolution Cloud coverage (optical) Daylight requirement (optical) Acquisition time depends on satellite orbit and duty cycle User/customer conflicts 26

33 Aerial vs. Satellite EO Strengths: Selectable flight path Very high resolution Allow for rapid revisit rates Can fly below clouds Can do in-situ measurements Not limited to EM based sensors Low cost Weaknesses: Spatial coverage Repeatability Endurance Long time series 24/7/365 In the Arctic, routinely remote sensing with manned aircrafts is nearly impossible due to low availability of suitable aircrafts Unmanned aircrafts (UAS) is suitable due to sparse population and low GA traffic 27

34 UAS is the next big thing The wars in Iraq and Afghanistan are ending; the UAS industry are looking at civilian sector US congress signs bill for full integration of UAS in national airspace by 2015 UAS industry is expected to reach $ annually by

35 Satellite vs UAS remote sensing 29

36 UAS research at Norut Airframe and platform Sensors and Algorithms System control and communications (Arctic) Scientiffic applications: Satellite product validation Meteorology Atmospheric and climate research Land monitoring (vegetation, fauna, hydrology) Ocean monitoring (sea-state, algae, sea-ice, icebergs) 30

37 CryoWing UAS CryoWing Micro (2012/13) MTOW: 2-4 kg Wingspan: < 2 m Range: 100 km Telemetry: UHF Payload capacity: 0.8 kg Fuel : Li-Pol Battery CryoWing Mk 1 (2007) MTOW: 35 kg Wingspan: 3.8 m Range 500 km Telemetry: 3G/GSM, Iridium, UHF Payload capacity: 10 kg Fuel capacity: 4.5 kg CryoWing Mk 2 (2012) MTOW: 50 kg Wingspan: 5.0 m Range 2000 km Telemetry: 3G/GSM, Iridium, UHF Payload capacity: 15 kg Fuel capacity: 15 kg 31

38 Bridging the gap between satellite and in situ measurements TerraSAR-X 32

39 Bridging the gap between satellite and in situ measurements TerraSAR-X 32

40 Bridging the gap between satellite and in situ measurements TerraSAR-X 32

41 Ideal tool to extend measurements in deep-field 33

42 Ideal tool to extend measurements in deep-field 33

43 Ideal tool to extend measurements in deep-field 33

44 UAS Cryowing Coverage 2000 Mk. km range 2 34

45 CryoWing mk I Instrumentation Current: Imaging Spectrometer 256 channels (950) nm wavelength (Fred Sigernes, UNIS) Digital camera 12 MPX (Canon 450D) C-band radar sounder (5.3 GHz) Laser profiler (20-60 mm rms, max 2KHz) Meteorological instr. package (Temp, hum, press, wind) Laser-scanner pts/s 10cm accuracy Turbulent heat flux sensors (Temporary loan, Univ. of Braunschweig) SST meter (IR thermometer) Trios Ramses spectrometer (up and down looking) GRIM OPS particle sampler (Volcanic Ash) Under development (SAR testing planned fall 2012 / spring 2013) Synthetic aperture radar (Ku-band, 15GHz) Drop sonde, met. and oil fingerprint lab on a chip Planned Methane sensor 35

46 UAS come in all sizes There is a lack of small/medium sized turn-key systems for ship based operations on a civilian budget Oil/seismic companies request ship based UAS capacity for detection of icebergs and crawlers. 24/7! 36

47 Newest research project UAS system for search and rescue Based on an small commercial disposable airframe Preprogrammed search patterns Can be operated by the ships ordinary crew, i.e. non-experts ASSUR Airborne Ship Safety using Robots Et pilotprosjekt i Unmanned Systems Laboratory 37

48 Summary Satellite SAR is the workhorse for monitoring of the arctic Used operationally for sea ice detection and classification, oil spill detection and ship detection Possible to retrieve information on ocean waves, winds and currents Detection of oil in ice is necessary due to increased oil and gas exploration and shipping in the arctic UAS is a coming technology for bridging the gap between satellite and in-situ measurements There is a demand for civilian ship based UAS systems for safe operations in ice infested waters 38

49 Questions? 39