Development of a Molecular Assessment High-Resolution Observation Spectrometer (MAHOS) for Microsatellites

Abstract

Compact and lightweight sensors with a high-frequency resolution are required for the passive observation of atmospheric water and oxygen emission lines at a reduced cost and power consumption. A molecular assessment high-resolution observation spectrometer (MAHOS) is developed as a compact, low power, digital fast Fourier transform spectrometer to be installed on a microsatellite. MAHOS has a compact design with dimensions of 0.154  0.125  0.040 m 3 and mass of 0.7 kg. It uses only a few materials including a field programmable gate array (FPGA) module with a lightweight aluminum alloy box. The highly stable spectrometer exhibits a sampling speed of 2.6624 GS/s and 16,384 frequency channels. The stability of the spectrometer is longer than 1200 s within the 1 GHz bandwidth. Thermal dissipation is achieved through a heat conductive gel filled in the gap between the most heat generating component, the FPGA and the aluminum alloy case. Results of a finite element analysis indicate that the design stiff and stable enough to survive in the launch environment. Thermal analysis indicates the durability of the system during operation. Even in space where heat dissipation is not possible, self-heating temperatures are not a problem for the FPGA. In the future, the performance of the spectrometer will be verified by conducting environmental tests.

Observation Capability of a Ground-Based Terahertz Radiometer for Vertical Profiles of Oxygen and Water Abundances in Martian Atmosphere

“…[21], this frequency range is decided by the tradeoff between O 2 at the upper sideband and H 2 O at the lower sideband frequency. After downconverted to the IF signals, the power level is amplified to turn this analog signal into a digital signal by a digital fast Fourier transform (FFT) spectrometer [24]. The system noise temperature is expected to be approximately 3000 K in the DSB mode.…”

“…The observation time was supposed to be ∼1 h during a day according to the power plan [22]. Further information related to TEREX-1 instrument, such as an optical system, including calibration loads and spectrometer can be found in Nakagawa et al [24], [25].…”