Mission design and operations of a constellation of small satellites for remote sensing

Abstract. Determination of aerosol optical properties with orbital passive remote sensing is a difficult task, as observations often have limited information. Multi-angle instruments, such as the Multi-angle Imaging SpectroRadiometer (MISR) and the POlarization and Directionality of the Earth's Reflectances (POLDER), seek to address this by making information-rich multi-angle observations that can be used to better retrieve aerosol optical properties. The paradigm for such instruments is that each angle view is made from one platform, with, for example, a gimballed sensor or multiple fixed view angle sensors. This restricts the observing geometry to a plane within the scene bidirectional reflectance distribution function (BRDF) observed at the top of the atmosphere (TOA). New technological developments, however, support sensors on small satellites flying in formation, which could be a beneficial alternative. Such sensors may have only one viewing direction each, but the agility of small satellites allows one to control this direction and change it over time. When such agile satellites are flown in formation and their sensors pointed to the same location at approximately the same time, they could sample a distributed set of geometries within the scene BRDF. In other words, observations from multiple satellites can take a variety of view zenith and azimuth angles and are not restricted to one azimuth plane as is the case with a single multi-angle instrument. It is not known, however, whether this is as potentially capable as a multi-angle platform for the purposes of aerosol remote sensing. Using a systems engineering tool coupled with an information content analysis technique, we investigate the feasibility of such an approach for the remote sensing of aerosols. These tools test the mean results of all geometries encountered in an orbit. We find that small satellites in formation are equally capable as multi-angle platforms for aerosol remote sensing, as long as their calibration accuracies and measurement uncertainties are equivalent. As long as the viewing geometries are dispersed throughout the BRDF, it appears the quantity of view angles determines the information content of the observations, not the specific observation geometry. Given the smoothly varying nature of BRDF's observed at the TOA, this is reasonable and supports the viability of aerosol remote sensing with small satellites flying in formation. The incremental improvement in information content that we found with number of view angles also supports the concept of a resilient mission comprised of multiple satellites that are continuously replaced as they age or fail.

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Dual-band circularly polarized antennas for GNSS remote sensing onboard small satellites

2010 7th International Symposium on Communication Systems, Networks & Digital Signal Processing (CSNDSP 2010) ◽

10.1109/csndsp16145.2010.5580454 ◽

2010 ◽

Cited By ~ 2

Author(s):

Moazam Maqsood ◽

Bidhan Bhandari ◽

Steven Gao ◽

Reynolt De Vos Van Steenwijk ◽

Martin Unwin

Keyword(s):

Remote Sensing ◽

Dual Band ◽

Circularly Polarized ◽

Small Satellites

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The Solaris Solar Polar Mission

10.5194/egusphere-egu2020-17703 ◽

2020 ◽

Author(s):

Donald M. Hassler ◽

Jeff Newmark ◽

Sarah Gibson ◽

Louise Harra ◽

Thierry Appourchaux ◽

...

Keyword(s):

Remote Sensing ◽

Solar Physics ◽

Polar View ◽

Ecliptic Plane ◽

Vantage Point ◽

Mission Design ◽

Future Research ◽

The Sun ◽

Gravity Assist ◽

Solar Observations

The solar poles are one of the last unexplored regions of the solar system. Although Ulysses flew over the poles in the 1990s, it did not have remote sensing instruments onboard to probe the Sun&#8217;s polar magnetic field or surface/sub-surface flows.We will discuss Solaris, a proposed Solar Polar MIDEX mission to revolutionize our understanding of the Sun by addressing fundamental questions that can only be answered from a polar vantage point. Solaris uses a Jupiter gravity assist to escape the ecliptic plane and fly over both poles of the Sun to >75 deg. inclination, obtaining the first high-latitude, multi-month-long, continuous remote-sensing solar observations. Solaris will address key outstanding, breakthrough problems in solar physics and fill holes in our scientific understanding that will not be addressed by current missions.With focused science and a simple, elegant mission design, Solaris will also provide enabling observations for space weather research (e.g. polar view of CMEs), and stimulate future research through new unanticipated discoveries.

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