1. Modern Remote Sensing: Imagery, Capabilities, Possibilities Paul F. Hopkins phopkins@syr.edu phopkins@syr.edu 315.470.6696 Workshop on Advanced Technologies in Real-Time Monitoring and Modeling for Drinking Water Safety and Security

2. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Presentation Content Basic principles of remote sensing Traditional and modern imagery resources Digital image processing  Preprocessing  Information extraction  Accuracy assessment Additional topics in image processing  Modern approaches to information extraction  Change detection  Data fusion A few examples

3. Paul F. Hopkins Remote SensingWater Safety and Security Workshop What is Remote Sensing? Remote distant or without physical contact Perceiving or studying interesting properties and objects without physically contacting them Sense perceive, feel, or study properties or objects

4. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Remote Sensing Process Three general stages  Acquiring image data  Processing image data to produce information  Communicating and using information Expectations must be reasonable  Information providers and users need to be knowledgeable  We understand the capabilities of the “traditional” image data sources and applications  Much less understanding about recent remote sensing technologies

5. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Energy-Surface Interactions When energy strikes a surface, three interactions can occur:  Reflection  Absorption  Transmission Generally, in remote sensing, reflection is of most interest  Reflectance  Degree of reflectance varies with wavelength  For visible energy, spectral reflectance produces the colors we perceive

6. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Presentation Content Basic principles of remote sensing Traditional and modern imagery resources Digital image processing  Preprocessing  Information extraction  Accuracy assessment Additional topics in image processing  Modern approaches to information extraction  Change detection  Data fusion A few examples

7. Paul F. Hopkins Remote SensingWater Safety and Security Workshop “Traditional” Remote Sensing Aerial photography and expert processing  image interpretation (photointerpretation)  Image measurement (photogrammetry) Satellite digital imagery of moderate resolution and computer processing  Weather satellites, Landsat, SPOT, and IRS  Image processing procedures –Enhancements and transformations –Spectral pattern recognition  Data continuity

8. Paul F. Hopkins Remote SensingWater Safety and Security Workshop “Modern” Remote Sensing (data) High spatial resolution digital imagery  On the order of 1m or better resolution  Exceptional spatial detail but many new challenges High spectral resolution imagery  Dozens, if not hundreds, of spectral bands  Fundamental changes in processing data High temporal resolution imagery Radar (microwave) digital imagery  Operational advantages  Information content very different than others Lidar

9. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Idea of Spatial Resolution 1 meter pixel 30 meter pixel

10. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Comparison of Spectral Resolutions MULTISPECTRAL Number of Bands: Tens Bandwidth : Wide (micrometers (  m)) (micrometers (  m)) Spectral Resolution: Medium HYPERSPECTRAL Number of Bands: Hundreds Bandwidth: Narrow (nanometers (nm)) (nanometers (nm)) (Narrower in reflective region than in emissive region) Spectral Resolution: High ULTRASPECTRAL Number of Bands: Thousands Bandwidth: Very Narrow (<1 nanometer) (<1 nanometer) Spectral Resolution: Very High Detects solids and liquids Detects and identifies solids, liquids, and some gases Detects and identifies solids, liquids, and gases

11. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Imaging Spectroscopy A single pixel A Pixel Hyperspectral data cube North East Spectral Hyperspectral data provides considerable information about the surface materials Multispectral imagery provides only a few channels of information Multispectral Reflectance

12. Paul F. Hopkins Remote SensingWater Safety and Security Workshop HYPERION Satellite system with spatial resolution: 30 m Spectral resolution: 220 bands (from 0.4 to 2.5 µm) http://eo1.gsfc.nasa.gov/Technology/Hyperion.html

13. MODIS Spectral resolution: 36 discrete spectral bands  Bands 1-19 in the range of 620 to 965 nanometers  Bands 20-36 in the range of 3.6 to 14.3 micrometers http://modis.gsfc.nasa.gov/ Spatial Resolution: Varies from 250 m to 1000 m Temporal: Entire Earth every one to two days Suited for regional applications Snow Cover to north Clouds to east February 28, 2002

14. Paul F. Hopkins Remote SensingWater Safety and Security Workshop ASTER Spectral resolution: 14 discrete spectral bands http://asterweb.jpl.nasa.gov/ Spatial: Varies band to band  15 m (bands 1-3 VNIR)  30 m (bands 4-9 SWIR)  90 m (bands 10-14 Thermal) VNIR band 3 has both forward and nadir looking components to produce stereo imagery Onondaga Lake Syracuse, NY June 19, 2000

15. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Backscatter Coefficient Images JERS-1 (April, 95) ERS-1 (August, 95)

16. Direct Geopositioning

17. Paul F. Hopkins Remote SensingWater Safety and Security Workshop LIDAR LIght Detection And Ranging The LIDAR instrument transmits light out to a target Some of this light is reflected and/or scattered back to the instrument where it is analyzed The change in the properties of the light enables some properties of the target to be determined The time for the light to travel out to the target and back is used to determine the range to the target Direct Geopositioning is crucial Digital Elevation Model or DEM is often produced

18. Paul F. Hopkins Remote SensingWater Safety and Security Workshop LIDAR image Tully Valley NY

19. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Presentation Content Basic principles of remote sensing Traditional and modern imagery resources Digital image processing  Preprocessing (restoration and enhancement)  Information extraction (classification)  Evaluation (accuracy assessment) Additional topics in image processing  Modern approaches to information extraction  Change detection  Data fusion A few examples

20. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Radiometric Restoration (sensor problems)

21. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Radiometric Restoration Downwelling Absorption & Scattering Direct & Adjacent Reflection Upwelling Absorption & Scattering Atmospheric Path Radiance

22. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Geometric Restoration

23. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Contrast Enhancement

24. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Ratios and Indices

25. Spectral Transform (PCA) 1 2 3

26. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Classification Perform statistical pattern recognition  Assume spectral (or other) measurements have unique patterns for the classes of interest  Use computer routines to generate statistical descriptions of these patterns and classes  Relate image values to the statistical descriptions of classes –Identify a strategy for deciding which class is most similar to the image location under consideration –Apply the decision strategy to all image values and assign class identities Postprocess, if desired

27. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Idea of Training

28. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Classification Result

29. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Accuracy Assessment Uses idea of a contingency or confusion table (also termed an “error matrix”) Compare a sample of reference locations with the class assigned by the classifier Classified Category Reference CategoryTotal AB A90696 B1094104 Total100 200

30. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Presentation Content Basic principles of remote sensing Traditional and modern imagery resources Digital image processing  Preprocessing  Information extraction  Accuracy assessment Additional topics in image processing  Modern approaches to information extraction  Change detection  Data fusion A few examples

31. Paul F. Hopkins Remote SensingWater Safety and Security Workshop “Modern” Remote Sensing (processing) Complementary technologies (GPS, GIS) Analytical photogrammetry and methods for geometrically processing imagery (DOQQs) Information technology and computer processing, generally and specifically for image processing  Image/Spatial modeling & expert classifiers  Adaptive computing  Change detection  Data fusion

32. Example Image Model (to find trees in high resolution imagery)

33. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Input Image

34. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Model Result

35. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Example of Adaptive Computing (Genetic Algorithm Approach) 20222423303318 30314039384329 30404953595450 41566384827672 35424750485363 32334250374331 19232624324032 202224233033183031403938432930404953595450415663... First rowSecond row Template of Tree Crown Chromosome

36. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Example Templates Manually generated GA- evolved

37. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Genetic Algorithm Output Manually generated template GA evolved template

38. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Genetic Algorithm Results ClassifiedTreeNot Tree User’s Accuracy Tree 411672% Not Tree 024100% Producer’s Accuracy 100%60%Overall: 80% ClassifiedTreeNot Tree User’s Accuracy Tree 370100% Not Tree 44090% Producer’s Accuracy 90%100%Overall: 95% Manually generated template GA evolved template

39. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Change Detection Numerous methods and the best method will depend on the type and amount of change Accurate registration is critical Some methods require accurate normalization to remove variations that are not caused by land changes  Atmosphere  Energy source – target – sensor variations Errors in the input images will compound each other and produce greater errors in the change detection results

40. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Image Fusion Many different image types (resolutions) Combining more than one type might provide enhanced capability  Sharpening with higher spatial resolution data  Phenological exploitation with high temporal resolution data  Enhanced spectral pattern distinctions with higher spectral resolution data Selected methods  Intensity – hue – saturation (ihs) transforms  Principal component substitution  High pass frequency substitution

41. Paul F. Hopkins Remote SensingWater Safety and Security Workshop IHS Transform

42. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Principal Component Substitution

43. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Presentation Content Basic principles of remote sensing Traditional and modern imagery resources Digital image processing  Preprocessing  Information extraction  Accuracy assessment Additional topics in image processing  Modern approaches to information extraction  Change detection  Data fusion A few examples

44. Paul F. Hopkins Remote SensingWater Safety and Security Workshop

45. Paul F. Hopkins Remote SensingWater Safety and Security Workshop

46. Paul F. Hopkins Remote SensingWater Safety and Security Workshop

47. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Onondaga Lake ASTER Image (19 June 2000)

48. Paul F. Hopkins Remote SensingWater Safety and Security Workshop Onondaga Lake Emerge Imagery (July 1999)

49. Paul F. Hopkins Remote SensingWater Safety and Security Workshop LIDAR Application 1997 1998

50. Paul F. Hopkins Remote SensingWater Safety and Security Workshop