BS in Electrical Engineering
Electrical Engineering Department
Day/Night Band (DNB) earth sensing and meteorological systems like the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) provide visible wavelength imagery 24 hours a day that is used primarily for cloud imaging in support of weather forecasting. This paper describes a compact push-broom imager that meets low light imaging requirements for DMSP OLS and the NOAA/NASA Joint Polar Satellite System (JPSS) as documented in the Integrated Operational Requirements Document  (IORD) including the imager design, system level concepts of operation for data collection, radiometric and spatial calibration, and data transmission to Earth. This small, lightweight imager complies with the low mass, low power CubeSat standard, and could be built into a variety of different satellites, for example, as a payload on Iridium NEXT, DMSP, or the International Space Station (ISS). Depending on power generation capabilities, the imager could be implemented as a free flyer in formation with other CubeSats or as a free flyer operating on its own. Desired performance specifications for this instrument can be divided into categories for each subsystem. The optic assembly will acquire scenes within a 112 degree field of view onto a Charge-Coupled Device (CCD) focal plane sensor with resolution of 742 m or better across the entire swath. Thermal stabilization of the CCD focal plane array is necessary to increase the Signal to Noise Ratio (SNR). Also, the instrument contains an image processor for handling image acquisition and storage to onboard flash memory. Altogether, the CubeSat DNB imager described here is expected to be capable of collecting imagery suitable for detecting clouds, monitoring energy usage in major cities, and detecting human activity at night, while simultaneously meeting specifications for the CubeSat platform. In addition to the example missions described above, launch opportunities for CubeSat missions are available for universities through the Educational Launch of Nanosatellites (ELaNa). Therefore, a cost effective mission for demonstrating this DNB imager under the CubeSat specification appears feasible and provides a quick, low cost solution for implementing this system.