NASA's QWIP-based Thermal Infrared Sensor to be integrated into Landsat satellite
15 February 2012NASA’s QWIP-based Thermal Infrared Sensor to be integrated into Landsat satellite
A new satellite instrument made by the US National Aeronautics and Space Administration (NASA) that uses gallium arsenide (GaAs)-based quantum-well infrared photodetector (QWIP) technology has arrived at Orbital Sciences Corp in Gilbert, AZ, USA, where it will be integrated into the next Landsat satellite, the Landsat Data Continuity Mission (LDCM).
Picture: Aleksandra Bogunovic reaches across the TIRS instrument to affix the corners of a Multi-Layer Insulation blanket. (Credit: NASA Goddard/Rebecca Roth).
The Thermal Infrared Sensor (TIRS) instrument will measure the Earth’s temperature with technology that applies quantum physics to detect heat. The engineering team at NASA’s Goddard Space Flight Center in Greenbelt, MD completed TIRS on an accelerated schedule, going from plans on paper to building the instrument in an unprecedented 43 months. “That’s a full year ahead of a typical schedule for a new space-borne instrument,” notes TIRS instrument manager Betsy Forsbacka.
The achievement has been enabled by the use of detector arrays that LDCM had on-hand, since Goddard played a major role in developing the technology, says LDCM project scientist James Irons. “TIRS will be the first time this technology is used in space,” he adds.
TIRS uses QWIP devices to detect long wavelengths of light emitted by the Earth with an intensity that depends on surface temperature. The thermal infrared wavelengths are well beyond the range of human vision and, while devices for thermal infrared night ‘vision’ have long been available, QWIPs offer a new lower-cost alternative to conventional infrared technology. Also, QWIP arrays are designed for sensitivity to specific wavelengths.
The QWIP’s design operates on the principles of quantum mechanics. GaAs chips trap electrons in an energy state ‘well’ until the electrons are elevated to a higher state by thermal infrared light of a certain wavelength. The elevated electrons create an electrical signal that can be read out and recorded to create a digital image. The QWIPs that TIRS uses are sensitive to two thermal infrared wavelength bands, helping it separate the temperature of the Earth’s surface from that of the atmosphere.
Temperature Sensor National - News
The Thermal Infrared Sensor (TIRS) instrument will measure the Earth's temperature with technology that applies quantum physics to detect heat. The engineering team at NASA's Goddard Space Flight Center in Greenbelt, MD completed TIRS on an accelerated
scientists from the University of Wisconsin-Madison show that nacre can also be deployed in the interest of science as a hard-wired thermometer and pressure sensor, revealing both the temperature and ocean depth at which the material formed.
scientists from the University of Wisconsin-Madison show that nacre can also be deployed in the interest of science as a hard-wired thermometer and pressure sensor, revealing both the temperature and ocean depth at which the material formed.
Long-term datasets from three different sources - the National Oceanic and Atmospheric Administration (NOAA), Remote Sensing Systems (RSS), which analyzes microwave data from NASA satellites, and the University of Alabama at Huntsville (UAH) - show
I remember a comment to me at the time by an engineer who was familiar with both it and similar devices from National Semiconductor: He said SPI is the sort of defacto standard that did not emerge out of the brain of any one engineer or company,
Semiconductor Vendors - About Temperature Sensors
Semiconductor thermometers are usually produced in the form of ICs, Integrated Circuits. There are many types, sizes and models.
Most are quite small and their fundamental design results from the fact that semiconductor diodes have voltage-current characteristics that are temperature sensitive. (That means that semiconductor triodes or transistors are also temperature sensitive.)
Needless to say, these devices have temperature measurement ranges that are small compared to thermocouples and RTDs , but, they can be quite accurate (e.g. ± 0.5°C or so) and inexpensive and very easy to interface with other electronics for display and control.
Listed below are links to some of the makers and suppliers of semiconductor thermometer devices.
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