EGU Land surface temperature measurement with an infrared camera, in-situ Emissivity measurement

Transcription

1 EGU 2018 Land surface temperature with an infrared camera, in-situ Emissivity J.P. MONCHAU 1*, M. MARCHETTI 2, L. IBOS 3, B. SAINTOT 2, M.KREMER 1, N. LALANNE 1 1 THEMACS Ingénierie, Champs sur Marne, FRANCE 2 CEREMA, Nancy, FRANCE 3 CERTES Université Paris Est, Créteil, FRANCE * (corresp. author): monchau@themacs.fr LST and emissivity in NAMIBIA Thermal mapping : City of Paris Principle of temperature correction Mobility in adverse winter conditions is a recurring problem that affects economy. The massive salting of roads affects the ecology of soils, surface waters and groundwater. To mitigate this alteration of ecosystems and to implement sustainable winter maintenance, thermal mapping of roads is a solution that enables to predict the risk of ice occurrence and snow accumulation and to limit the salting to what is strictly necessary. To achieve an unbiased result it is necessary to know the thermal behaviour of the road. NEXT Instrumentation Emissivity Winter risk evaluation

2 EGU 2018 Land surface temperature with an infrared camera, in-situ Emissivity J.P. MONCHAU 1*, M. MARCHETTI 2, L. IBOS 3, B. SAINTOT 2, M.KREMER 1, N. LALANNE 1 1 THEMACS Ingénierie, Champs sur Marne, FRANCE 2 CEREMA, Nancy, FRANCE 3 CERTES Université Paris Est, Créteil, FRANCE * (corresp. author): monchau@themacs.fr LST and emissivity in NAMIBIA Thermal mapping : City of Paris In order to measure the surface temperature of the road with a radiative method, its emissivity and the radiation from the half space seen from the surface have to be determined. Since the thermal and environmental characteristics of the road may change along the section considered, the temperature Instrumentation Emissivity Winter risk evaluation Principle of temperature correction PREV. NEXT

3 EGU 2018 Land surface temperature with an infrared camera, in-situ Emissivity J.P. MONCHAU 1*, M. MARCHETTI 2, L. IBOS 3, B. SAINTOT 2, M.KREMER 1, N. LALANNE 1 1 THEMACS Ingénierie, Champs sur Marne, FRANCE 2 CEREMA, Nancy, FRANCE 3 CERTES Université Paris Est, Créteil, FRANCE * (corresp. author): monchau@themacs.fr LST and emissivity in NAMIBIA Thermal mapping : City of Paris Principle of temperature correction must be carried out on the entire road. This method is conventionally called "thermal mapping". It consists in measuring the radiation emitted from the road using an apparatus set on a vehicle embedded into the traffic. It is important to have an accurate value of the directional emissivity of the monitored surface in the spectral band and in the direction the detector aimed. PREV. Instrumentation Emissivity Winter risk evaluation

4 A Land surface temperature in Namibian desert (ESA project) LST and emissivity in NAMIBIA Surf1 W Alu B Surf2 A Example of temperature calculation from luminance and reference temperature Thermal picture : the temperatures of the surfaces references (White, Black, Alu) are measured. The luminance of the 5 surfaces are measured B Experimental dispositive of. A: reference surfaces B: soil viewing NPL

5 THERMOCITY : Thermal mapping for winter risk (city of Paris) The experimental dispositive on the roof of a car Measurement in progress during the winter Thermal mapping : City of Paris Results Example of thermal image Field of view of the camera Radiation of the environnement

6 THERMOCITY : Thermal mapping for winter risk (city of Paris) Example of winter risk evaluation The was made by two vehicles (from THEMACS and CEREMA) and simultaneous an aerial thermography was done by the LNE (National metrology institute in France) with a plane all around the city of Paris 6

7 Two method of temperature correction : Two reference black bodies Constitution of the black body Three reference surfaces for temperature correction Surf1 W Alu B Surf2 Principle of temperature correction

8 Temperature and hygrometry sensors Infrared window Infrared camera FLIR A35 Control pannel Meteorological parameters Sensors : - Air Temperature - Air humidity - Surface/black body temperature POE Connexion CPU: RASPBERRY Pi3 Data logging: ARDUINO Serial communication Instrumentation Data storage on a SSD disk Sending data by 3G/GPRS to a data base

9 On-site emissivity Directional emissivity Laboratory spectral emissivity On-site spectral emissivity Emissivity

10 SPIDER II instrument Experimental device Thermocouple for rear temperature Peltier Sample Power supply 80V/120A Stepper motor IR camera SC7300 Micro-computer Computer Under Labview Next

11 SPIDER II instrument Experimental device Micro-computer Experimental parameters - Periodic thermal excitation applied by 16 thermoelectric coolers - FLIR SC7300 long wave infrared camera (spectral range µm, matrix ) cooled by a Stirling engine. NETD=0.02K - Sampling frequency f e =0.5 Hz - Sampling period of thermal wave : 640s - Observation angles from 0 to 88.5 (goniometer) - Experimental setup controlled by a LabView program Stepper motor Sample IR camera SC7300 Prev. Next

12 SPIDER II instrument Experimental device Prev. Next

13 SPIDER II instrument Experimental protocol Thermal excitation (front face of the sample) - Sine wave on Peltier modulus at T=640s Measurements with the camera: 0.5s (25 frames at 50Hz for each angle). Measurement from 0 to 88.5 and from 88.5 to 0 (118 s during 236s) Examples of bituminous concrete sample Examples of thermal images with ROIs Prev. Next

14 T Source ( C) T Source ( C) SPIDER II instrument Experimental protocol Calculation of the directional emissivity 45 Angle = Angle = 21 2 Angle = T App,Surface ( C) t (s) t (s) T Source ( C) T App,Surface ( C) 0 T App,Surface ( C) t (s) t (s) Prev. Next

15 T S T SPIDER II instrument Experimental protocol t (s) Calculation of the directional emissivity 2 1 T App,Surface ( C) t (s) Prev. Next

16 Relative emissivity Results Absolute emissivity Angle( ) Angle( ) Spectral emissivity Prev. Next

17 Results Relative emissivity s n 0.8 ( ) Sample 1 Sample 2 Sample 3 Glass PVC 0 Prev.

18 Laboratory spectral emissivity of sample from Gobabeb (Namibian desert) A: Frontier spectrometer B: Gobabeb quartz gravel C and D: Gobabeb sand Next

19 Laboratory spectral emissivity of sample from Gobabeb (Namibian desert) Gravel 1 Gravel 2 Emissivity for different spectral band Material 2-17µm 8-14µm 8-12µm µm Sand Gravel Gravel 3 Gravel Gravel and sand from Namib desert show a very different behaviour, specially in the 8-12µm spectral band. the great difference of spectral behaviour shows that the emissivity depends on the ratio of these two components Sand 1 Sand 2 Sand Prev.

20 On-site spectral 20 The 4300 Handheld FTIR is the first of its kind employing lightweight ergonomics, ease of use, ruggedness, and flexibility into one system. The 4300 weighs in at approximately 2kg. With its lighter weight and new design, the ergonomics of the system make it ideal for field use and deployment into non-laboratory situations. A variety of sampling interfaces (Diffuse Reflectance, External Reflectance, Grazing Angle, Diamond ATR, Ge ATR) allows the user to easily transition from one sample type to another while on the go, with no alignment or adjustments necessary. Sample types typically include infrared absorbing and scattering surfaces, reflective metal surfaces with coatings and films as well as analysis of bulk materials including powders and granules.

21 On-site emissivity with EM3 A the head B : on Gobabeb site The device used is the emissivity measuring device EM3 from THEMACS Ingénierie. This device is the result of a patent deposited in 2012 by the CERTES (University Paris Est Créteil). Two spectral band can be used : 8-14µm or broad band (1-50µm). Next

22 On-site emissivity with EM3 The device measure the hemisphéricdirectional reflectance (ρ) : ε = 1 ρ Thermopile for measuring reflected flux Thermopile for measuring incident flux IR source: hot cylinder mobile screen C Fixed screen D Sample Inside view - rotating frequency: 1.5 Hz - fast (few seconds) - Spectral band: 1-50µm and 8-14µm - easy to care - patented device Prev. 22

23 Winter risk evaluation Thermal mapping Mathematic model Meteo forecast ICING ALERT Winter risk evaluation

24 Thermophysical properties (Emissivity, Conductivity, diffusivity, ) Instrumentation Thermography THEMACS Ingénierie is a spin-of from an academic laboratory. The team: 6 assistant-professors from the CERTES laboratory (Centre d Etude et de Recherche en Thermique, Environnement et Systèmes) of the Paris-Est Créteil University (UPEC) - Expertise in thermal science, - Thermal characterization of materials - Development of specific devices for the monitoring of buildings, civil engineering structures and environment