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Method Name: |
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Airborne infrared thermography |
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Method Type: |
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Thermic Methods
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Assigned Problems: |
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Principle: |
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Determination of ground temperature using airborne infrared surface temperature measurements (thermal/ infrared radiation; remote sensing). |
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Keywords: |
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Airborne thermal imaging; airborne geophysics; infrared measurements; thermal and infrared radiation; temperature distribution |
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Prerequisites: |
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- Existence of thermal contrast
- Weather / climate conditions: images may be difficult to interpret if recorded over snow-covered areas, wet ground, frost or during high wind.
- Clouds influence measurements significantly.
- Images may be distorted due to aircraft roll.
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Resolution: |
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Instrument depending; in general, increasing thermal resolution decreases the spatial resolution, and vice versa.
Depth of investigation: Surface heat distribution, but also covered heat sources (e.g., smouldering) may be identifiable. |
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Expected Results: |
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- Measured parameter: Infrared thermography measures the intensity of the emitted electromagnetic radiation of a body
- Data analysis: The measured signal may then be converted to temperature (emission coefficient / emissivity must be known)
- Interpretation: Infrared thermography: qualitative interpretation of relative thermal anomalies assuming that the measured signal (intensity of electromagnetic radiation) is correlated to the true temperature.
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Combination with other Methods: |
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- Required additional information: Weather conditions, camera information (valuable wavelength, etc.), camera setup, flight parameter (for processing / interpretation)
- Related add-on information: Ground infrared thermography and ground temperature probing
- Independent additional information: Investigations on site / ground depending on field of applications
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Operating Expense: |
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- Crew size: flight crew (normally 2 persons)
- Acquisition speed: several measurements per hour
- Processing: 1 - 2 days per measuring day
- Equipment rental costs: high
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Parameters to specify: |
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- Line spacing; survey area is divided up into parallel tracks. Tracks should partially overlap to allow for wind gusts, aircraft roll or positional errors
- Line direction
- Flight altitude or height above ground; flight altitude: depending on target size from several tens to several hundreds of m
- Tolerances for altitude and positional deviations
- Weather conditions
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QC Documents: |
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- Field notes (e.g., all activities, effective time schedule, present personnel)
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Products: |
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- Map/ images (or profiles) of temperature distribution
- Interpretation
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