===== Thermal Remote Sensing =====

==== Drone - DJI Mavic Enterprise 3 Thermal ====

  * [[https://enterprise.dji.com/de/mavic-3-enterprise]]
  * [[https://copterpro.de/shop/drohnen-komplettsets/djimavic3enterprise/]]

==== Calibration Field Targets ====
  * Prior to + after flight measure targets with handheld thermometer. Or place thermocouples + logger under panels!?
  * 30x30 cm ?
  * Unknown emissivity measurement:
    * [[https://www.calex.co.uk/find-correct-emissivity-setting-infrared-temperature-sensor/]]

  *** High-emissivity** 
      * Matte black-painted aluminum
      * ε≈0.97
      * Purpose: Temperature reference
      * **Coatings / Foils:**
        * [[https://www.nextel-coating.com/de/shop/artikel/nextel-velvet-coating-811-21-9218-schwarz]]
        * [[https://de.acktar.com/tiefschwarz-beschichtete-folien-filme-2/]]

  *** Low-emissivity** 
      * Polished aluminum sheet
      * ε≈0.04-0.06
      * Purpose: Reflected apparent temperature

==== IR Termometers ====
     * [[https://www.conrad.com/en/p/fluke-566-ir-thermometer-display-thermometer-30-1-40-650-c-contact-measurement-122370.html]]
     * [[https://www.voelkner.de/products/542871/Fluke-568EX-Infrarot-Thermometer-Optik-501-40-800C-Kontaktmessung.html]]
     * [[https://www.reichelt.de/de/de/shop/produkt/infrarot-thermometer_568_ir_und_kontakt_-40_bis_800_c-110173]]

     * **Calibration:**
       * https://www.fluke.com/de-de/mehr-erfahren/blog/kalibrierung/infrared-thermometer-calibration

==== Lab Temperature Calibration (potential field use?) ====
  * [[https://www.conrad.de/de/p/voltcraft-irs-350-kalibrator-kalibriert-iso-2236161.html]]
  * [[https://www.messbar.de/kalibrierstrahler-optris-br400-fuer-waermebildkameras]]
  * [[https://www.messbar.de/Optris-BR20AR-Referenzstrahler]]

==== Research Papers ====

  * WUR :!: Calibration + Processing
     * [[https://www.sciencedirect.com/science/article/pii/S1569843224005405]]
   * [[https://www.sciencedirect.com/science/article/pii/S1569843224005405]]
   * [[https://www.mdpi.com/2072-4292/17/15/2746]]
   * DJI Thermal Format Conversion
     * [[https://www.mdpi.com/1424-8220/24/19/6267]]
   * [[https://www.sciencedirect.com/science/article/abs/pii/S1350449523001998]]

==== Software / Code ====

  * [[https://github.com/DanGeospatial/dji_m3t_rpeg_to_tif/]]
  * [[https://www.dji.com/de/downloads/softwares/dji-dtat3]]
  * [[https://www.dji.com/de/downloads/softwares/dji-thermal-sdk]]
  * [[https://github.com/SanNianYiSi/thermal_parser]]
  * [[https://docs.webodm.net/how-to/process-thermal-images/]]
  * [[https://webodm.net/thermaltools]]

==== 💡 IDEAS ====

  * Use a Sous Vide (keeps temp stable) in a pot for experiment flights 
     * Maybe two? one for low temp one high

==== Must do's for data acquisition ====

  * [[https://dl.djicdn.com/downloads/zenmuse_xt/en/sUAS_Radiometry_Technical_Note.pdf]]

==== Leaf Temperature Measurement for Validation ====

  * Example: [[https://www.implexx.io/temperature/leaf-temperature-sensor/]]
  * Thermocouple on a clamp 
  * Use thermocouple of IR-Thermometer 
  * 3D-Printed clamp: [[https://www.printables.com/model/974751-clamp-print-in-place]]
{{:eolab:thermal:phyto-sensor-lt-1m-leaf-temperature-sensor-web.jpg?nolink&400|}}

==== Field Mission Sheet ====

   *** Pre-Flight** 
     * Record air temperature, relative humidity, wind speed.
     * Measure true temperature of high-emissivity target (IR thermometer or thermocouple).
     * Measure apparent temperature of low-emissivity target (reflected sky).
     * **Set camera:**
       * Emissivity = 0.98
       * Reflected temperature = from low-ε target
       * Atmospheric temp = air temp
       * RH = measured RH
       * Image type = radiometric JPEG/TIFF
   *** In-Flight**
     * Hover ~10 m for 30 s (thermal stabilization).
     * Capture targets at start of mission (low altitude, nadir view).
     * Fly survey (consistent height/speed).
     * Re-capture targets at end of mission.
     * Log times, environmental data.
   *** Post-Flight Processing**
     * Extract target pixel temperatures.
     * Apply correction to thermal mosaic.
     * Validate canopy temps vs spot measurements.