ECE5320 Mechatronics Assignment#01: Literature Survey on Sensors and Actuators Topic: AIRS InterferometerOutlineReference listTo explore further (survival pointers of web references etc)Major applicationsOverview of SensorAQUA Platform and StatisticsGrating SpectrometerGrating Spectrometer SensorsGrating Spectrometer Sensors (cont.)Slide 11Grating Spectrometer OpticsFocal Plane LayoutInstrument PowerAIRS InterferometerSpecificationsSpecifications (Cont.)AIRS Block DiagramScan GeometryCalibrationCalibration (cont)Sensor OutputsRadiance ExplanationTemperature RetrievalsConclusionECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Assignment#01: Literature Survey on Sensors and Actuators Topic: AIRS InterferometerPrepared by:Marcus SmithDept. of Electrical and Computer Engineering Utah State University(435)797-3054 (ECE Dept.)3/10/200601/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-2Outline –Reference list–To probe further–Major applications–Sensor Overview•Grating Spectrometer•Optics•Focal Plane•Power–System Specs, Geometry, and Block Diagram–Calibration–Output Product–Conclusion01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-3Reference list•Strow, Larabee. "Atmospheric Infrared Sounder (AIRS)." ASL/UMBC. UMBC-NOAA. 15 Feb. 2006 <http://asl.umbc.edu/pub/airs/airs.html>. •Graham, Steven. "AQUA Project Science." 18 Apr. 2005. NASA Goddard SPaceflight Center. 15 Feb. 2006 <http://aqua.nasa.gov/about/instruments.php>. •Okenak, Sharon. "AIRS Technology Summary." NASA-JPL AIRS Overview. NASA-JPL-Cal Tech. 15 Feb. 2006 <http://www-airs.jpl.nasa.gov/technology/technology_index.html>. •Smith, Marcus. “AIRS-Algorithm-Study-Udate-2_2006.ppt” SDL. •"Radiance." Wikipedia, the free encyclopedia. 26 Jan. 2006. Wikipedia. 15 Feb. 2006 <http://en.wikipedia.org/wiki/Radiance>.01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-4To explore further (survival pointers of web references etc) •http://www-airs.jpl.nasa.gov/technology/technology_index.html•http://asl.umbc.edu/pub/airs/airs.html•http://oco.jpl.nasa.gov/instrument.html•http://en.wikipedia.org/wiki/Interferometer01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-5Major applications •IR Sensor is used on the Aqua platform for atmospheric remote sensing and modeling.•IR Radiance data is passed through several scientific algorithms to retrieve atmospheric constituents such as temperature, water vapor, CO2, CO, etc. These components can be determined at each of the 100 defined pressure levels between 0 and 705 Km. This data can be retrieved in 47 minutes from time of downlink and introduce into the global atmospheric modeling software.•Since IR frequencies are susceptible to cloud contamination AIRS works in conjunction with AMSU which is a passive sensor in the microwave frequency range and is less susceptible to cloud contamination.01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-6Overview of Sensor•The AIRS sensor is part of the suite of atmospheric sensors located on the Aqua satellite which is part of the EOS (Earth Observing System) which is a joint venture between NASA, DOD and NOAA to obtain more accurate atmospheric data for modeling and forecasting purposes.•The AIRS sensor has a high spectral resolution and covers an infrared bandwidth between 3.7 o 15.4 μm.•The AIRS sensor is an array grating spectrometer that has 2378 IR spectral channels in the above mentioned spectral range.01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-7AQUA Platform and Statistics•The AIRS spectrometer is one of six instruments located on the AQUA platform. Each sensor contributes to the entire climate model package. This review will focus on the AIRS interferometer.01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-8Grating Spectrometer•Light enters an aperture and strikes a reflection grating which is composed of several different surface angles.•These angles cause different the IR wavelengths to be reflected to various points where they can strike 1 of 2378 HgCdTe detectors depending on their wavelength. This way all measurements are made at the same timehttp://oco.jpl.nasa.gov/instrument.html01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-9Grating Spectrometer Sensors•The HgCdTe sensors are super cooled to 58K in order to allow the most accurate reading and reduce inherent noise. The spectrometer is maintained at 155K by a passive radiator. The IR sensor field of view is shielded from the Earth’s thermal energy by a deployable heat shield. The super cooled detectors maintain the 58K by use of a 1.5 W capacity Split Stirling pulse tube cryocooler.•Each spectral sample takes 22.4 ms and has a spatial resolution of 13.5 Km at an altitude of 705.3 Km01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-10Grating Spectrometer Sensors (cont.)•The AIRS spectrometer uses echelle-grating with a multiple aperture design (11 Apertures) to disperse the IR energy coming into the apertures and through a series of mirrors onto the focal plane arrays.•AIRS uses IR band pass filters to eliminate IR energy at frequencies other than the desired range. The wavelength entering the sensor can be adjusted by altering the ratio of mercury to cadmium in the HgCdTe sensors.01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-11Grating Spectrometer Sensors (cont.)•The AIRS spectrometer uses echelle-grating with a multiple aperture design (11 Apertures) to disperse the IR energy coming into the apertures. Pictured below is the echelle-grating:http://www-airs.jpl.nasa.gov/graphics/technology/echellegrating.jpg01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-12Grating Spectrometer Optics•This diagram shows how IR energy is passed through the 11 apertures and focused on the focal plane assembly.http://www-airs.jpl.nasa.gov/graphics/technology/optics_diagram.jpg01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-13Focal Plane LayoutThe focal plane assembly uses PV (Photovoltaic) and PC (Photoconductive) modules to image the dispersed energy. These hybrid systems are arranged into 17 separate arrays consisting of 12 modules each.
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