NASA DESIS ISS
Power Supply for the VNIR FPA camera and front end electronics
About the mission – DESIS data from the ISS available for science and research!
DESIS (DLR Earth Sensing Imaging Spectrometer for the ISS-MUSES platform) is a hyperspectral instrument with additional steering capability and has been acquiring imagery since October 2018.
The DESIS hyperspectral imager, operating on the International Space Station,
It is the first instrument to be installed on ISS attached to the MUSES platform, which provides power, data-flow, and inertial pointing stabilization for up to four instruments.
Because of its high spectral scanning rate DESIS can record spectral signatures that vary with the chemical composition and physical structure of the earth’s surface. With DESIS measurements it is thus possible to monitor the quality of water bodies, map vegetation types, record vegetation stress, as well as characterize soil mineral resources.
Technical VNIR FPA Detector Concept
The DESIS Imaging Spectrometer FPAs require two different 2-dimensional detector array types, with one dimension for the spatial scan along a ground image line repre-sented by the spectrometer slit, the second dimension for the reproduction of the spectrum per either spectral regime.
The two detectors have a wavelength overlap of 100 nm for reference and matching the two spectra. The resulting image data together with the track of the satellite will then constitute the often quoted “image cube”, a data set with spatial and spectral information.
The APCON power supply is integral part of the VNIR FPA electronics. It is located in a single box together with the camera front end electronics.
The power supply shall permanently generate the supply voltage for the FEE digital controller and S/C interfaces. The detector voltages shall be generated as row voltage and will be finally conditioned on the FEE or the SA. The detector voltages shall be switched on and off via digital command signals from the FEE.
The VNIR power supply by APCON consists of the following functional blocks:
- Input filterInput
- Current Limiter with latch
- Primary Under-Over-Voltage Protection
- PWM Pre-Regulator
- Push/Pull Power stage including transformer
- Rectifier and Output Filter
- Secondary Buck & Series Regulators
- Monitoring (Power On Reset Circuit)
- Monitoring (Output Current & Voltage
- Measurement of Analog & Digital Voltages by ADC)
- Measurement of Peltier Voltages by ADC)
- DAC-Command Interface for the Peltier Voltage Control