2011 GIS Symposium 1

Transcription

1 2011 GIS Symposium 1

2 What is Thermal Imaging? Infrared radiation is perceived as heat Heat is a qualitative measure of temperature Heat is the transfer of energy Energy can be quantitatively i measured with a special camera 2011 GIS Symposium 2

3 All Objects Radiate Energy All objects radiate energy (heat) above zero Kelvin Zero Kelvin = -459 F 32 F >1,000 F 2011 GIS Symposium 3

4 What is Thermal Imaging? Detection of thermal infrared energy It is a way to look at the heat signature of an object 2011 GIS Symposium 4

5 History of Thermal Technology Military developed d thermal imaging i in 1960 declassified thermal technology in 1992 Thermal cameras were commercialized in GIS Symposium 5

6 Thermal Technology Myths Thermal lis not t Night htvision i magnified visible light Thermal is not X-Ray cannot penetrate t walls 2011 GIS Symposium 6

7 Electromagnetic Spectrum Atmospheric Thermal Windows nm ,000 5,000 8,000 14,000 nm Blue Green Red Near Infrared Mid-Wave Thermal (MWIR 3-5μm) Long-Wave Thermal (LWIR 8-14μm) 2011 GIS Symposium 7

8 Categories of Heat Passive Absorb and re-radiate heat from a direct source Sidewalks Soil Water People Active Generate and emit heat tin low to medium strength th Animals Living Organisms Direct Constant high strength source the emits IR energy Sun Fire Radiant Heater 2011 GIS Symposium 8

9 Thermal Bands MWIR versus LWIR each band has advantages and limitations In General MWIR Is good for direct heat sources Must be a cooled sensor Prone to solar flare during daytime use outdoors LWIR Is good for passive and active heat sources Generally non-cooled technology Can be used for outdoor, daytime applications 2011 GIS Symposium 9

10 Heat Transfer Methods Conduction Heat (energy) is transferred through direct contact Can be measured with thermal camera Convection Heat (energy) is transferred through moving air Radiation Energy moves as electromagnetic waves through the air and is transferred upon striking object cannot see the energy while traveling through the air 2011 GIS Symposium 10

11 Older Technology Based on video camera technology Analog display of warmer (white) cooler (black) GPS position and other data overlaid on video frame 2011 GIS Symposium 11

12 Latest Technology Digital Acquisition data is saved in temperature values (not relative scale) Radiometrically Calibrated External GPS/IMU Time Stamp Post-Process data and correct for ambient temperature, relative humidity, emissivity 2011 GIS Symposium 12

13 Thermal Camera Resolution Medium Format Detectors Large Format Detectors 320 x 240 Pixels 640 x 480 Pixels (76,800 pixels = 0.07-megapixel) gp (307,200 pixels = 0.3-megapixel) 2011 GIS Symposium 13

14 Why isn t Thermal Imagery Widely Available? Thermal cameras are very expensive digital GPS/IMU Difficult to integrate analog technology for mapping data storage analog Integrate resolution flight nav Time consuming to georeference very low resolution images software thermal mosaic 2011 GIS Symposium 14

15 Technology & Services Digital Sensor System designed for mapping applications Cornerstone Mapping s Digital Camera System True Color & CIR Imagery Airborne GPS/IMU Flight Navigation Two Aircraft Cessna 182 Piper Saratoga 2011 GIS Symposium 15

16 Technology & Services Large and Small Projects Cornerstone Mapping s Digital Camera System Digital Orthophotos Volumetric Calculations Contour Mapping Image Processing GIS Services 2011 GIS Symposium 16

17 System Components Current Mapping System Camera Controller Removable Hard Drive IMU Processor IMU Camera Thermal Camera Power Distribution Flight Nav Azimuth Mount Sensor Fusion to Create a Multi-Sensor Imaging System 2011 GIS Symposium 17

18 Thermal Camera Sensitivity Temperature Range F C ±0.5 C ±1.5 C ± 2 C Sensitive to Temperature Differences Precision: < 0.1 C 2011 GIS Symposium 18

19 Data Collection Dual Sensor Collection If thermal imagery is collected during the daytime, simultaneous True Color or Color-Infrared (CIR) can be acquired 2011 GIS Symposium 19

20 Dual-Camera Field of View (FOV) Similar FOV enables cost-efficient data collection 2011 GIS Symposium 20

21 Image Resolution Thermal cameras are lower resolution than color cameras Color Image Thermal Ratio: 1 thermal pixel = 9 color pixels 2011 GIS Symposium 21

22 When Should you Collect Thermal Data? time-of-day Depends on Project... Measuring thermal loading After Sunset / Dusk Rooftop survey for water damage Maximize temperature differences Assessment of residential heat-loss Counting wildlife Nighttime Measure maximum temperature Water quality/habitat of streams Daytime 2011 GIS Symposium 22

23 Temperature Cross-Over Diurnal Effects Temperature for different objects will be the same twice a day. Air Temperature Ground Water Temperature Thermal Crossover morning evening Time of Day 2011 GIS Symposium 23

24 Thermal Loading N 3:00 PM 20 F outside temperature 2011 GIS Symposium 24

25 Atmospheric Considerations High humidity will diffuse heat signature High wind will blend the heat signature Recent rain will affect apparent temperature 2011 GIS Symposium 25

26 Thermal Imagery Applications 2011 GIS Symposium 26

27 Building Heat Loss Green Energy Projects Average Roof Temp 7 F Average Roof Temp 11 F 2011 GIS Symposium 27

28 City-Wide Energy Assessment Green Energy Projects Clip thermal data based on building footprints Calculate average rooftop temperature Analyze data for target programs 2011 GIS Symposium 28

29 Roof Top Survey Low-Slope Roofs Dark spots reveal areas of moisture penetration Wet areas warm/cool at different rates than dry areas 2011 GIS Symposium 29

30 Roof Top Surveys Daytime - Color Nighttime - Thermal 2011 GIS Symposium 30

31 Underground Steam Lines Excess Heat Loss Poor Insulation 2011 GIS Symposium 31

32 Agriculture 2011 GIS Symposium 32

33 Agriculture Water Stress Nutrient Stress Tissue Damage (insects, disease) Leaf Structure Stomata Oxygen Water CO 2 Evaporative Cooling (heat transfer) 2011 GIS Symposium 33

34 Migratory Bird Survey Proximity to food sources (corn fields) Disturbance factors (roads and bridges) Distance to wetland meadows 2011 GIS Symposium 34

35 Natural Resources Stream habitat assessments Temperature Profile 2011 GIS Symposium 35

36 Irrigation Canals Canal leak increases soil moisture Soil moisture affects thermal property p of soil Thermal patterns illustrate size and location of leak 2011 GIS Symposium 36

37 Power Plant Inspection Identify areas of heat loss 2011 GIS Symposium 37

38 Power Plant Discharge after diffuser installed Diffuser changed water flow dynamics in the lake Thermal data courtesy of CALMIT 2011 GIS Symposium 38

39 Before After Thermal data courtesy of CALMIT 2011 GIS Symposium 39

40 Power Line Survey Electricity flowing through wire generates heat Flaws in wire and poor connections create resistance Heat causes equipment failure 2011 GIS Symposium 40

41 Thermal Imagery in GIS? Treated the same as an aerial photo Standard GeoTiff format Data extraction and analysis can be performed Overlay other data layers 2011 GIS Symposium 41

42 Data Format & Representation 16-bit GeoTiff Pixel value represents temperature Apply color ramp in ArcGIS -or- Classify by temperature range 2011 GIS Symposium 42

43 Data Fusion Image Overlay 2011 GIS Symposium 43

44 Data Fusion Pan Sharpening 2011 GIS Symposium 44

45 Summary Airborne Thermal Imaging Cutting-Edge g Technology Numerous Applications Integrated with Existing Mapping Capabilities 2011 GIS Symposium 45