K. Muinonen
A5002639269- Astro and Planetary Science
- Planetary Science and Exploration
- Stellar, planetary, and galactic studies
- Atmospheric aerosols and clouds
- Isotope Analysis in Ecology
- Astronomy and Astrophysical Research
- Optical Polarization and Ellipsometry
- Geomagnetism and Paleomagnetism Studies
- Random lasers and scattering media
- Space Satellite Systems and Control
- Space Exploration and Technology
- Atmospheric Ozone and Climate
- Scientific Research and Discoveries
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Geology and Paleoclimatology Research
- Geophysics and Gravity Measurements
- Geological and Geochemical Analysis
- Aeolian processes and effects
- Calibration and Measurement Techniques
- Spacecraft and Cryogenic Technologies
- Atmospheric chemistry and aerosols
- Geochemistry and Geologic Mapping
- Solar and Space Plasma Dynamics
- Infrared Target Detection Methodologies
University of Helsinki
2016-2025
Helsinki Institute of Physics
2014-2024
Finnish Geospatial Research Institute
2014-2023
Osservatorio Astrofisico di Torino
2002-2022
Observatoire de la Côte d’Azur
2022
University of Manchester
2022
European Space Research and Technology Centre
2022
Laboratoire d'Astrophysique de Bordeaux
2022
Institute of Astronomy
2022
Global Social Observatory
2022
We present measured scattering matrices as functions of the angle in range 5°–173° and at wavelengths 441.6 nm 632.8 for seven distinct irregularly shaped mineral aerosol samples with properties representative aerosols Earth's atmosphere. The samples, i.e., feldspar, red clay, quartz, loess, Pinatubo Lokon volcanic ash, Sahara sand, represent a wide variety particle size (typical diameters between 0.1 100 μm) composition (mainly silicates). investigate effects differences complex refractive...
The ESA-JAXA BepiColombo mission will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at Mercury as well their interactions with the solar wind, radiation, interplanetary dust. Many scientific instruments onboard spacecraft be completely, or partially devoted study near-space environment of complex processes that govern it. issues remain unsolved even after MESSENGER ended in 2015. specific...
The Gaia spacecraft of the European Space Agency (ESA) has been securing observations solar system objects (SSOs) since beginning its operations. Data Release 2 (DR2) contains a selected sample 14,099 SSOs. These asteroids have already identified and numbered by Minor Planet Center. Positions are provided for each observation at CCD level. As additional information, apparent brightness SSOs in unfiltered G band is also observations. We explain processing SSO data, describe criteria we used...
Abstract The SIMBIO-SYS (Spectrometer and Imaging for MPO BepiColombo Integrated Observatory SYStem) is a complex instrument suite part of the scientific payload Mercury Planetary Orbiter mission, last cornerstone missions European Space Agency (ESA) Horizon + science program. will provide all imaging capability spacecraft. It consists three channels: STereo Channel (STC), with broad spectral band in 400-950 nm range medium spatial resolution (at best 58 m/px), that Digital Terrain Model...
The third data release by the Gaia mission of European Space (DR3) is first to provide community with a large sample observations for more than 150 thousand Solar System objects, including asteroids and natural planetary satellites. contains astrometry (over 23 million epochs) photometry, along average reflectance spectra 60518 osculating elements. We present an overview procedures that have been implemented over several years development tests process at level accuracy can reach. illustrate...
Abstract Novel Monte Carlo techniques are described for the computation of reflection coefficient matrices multiple scattering light in plane-parallel random media spherical scatterers. The present theory is composed coherent backscattering and radiative transfer. In transfer part, Stokes parameters escaping from medium updated at each process predefined angles emergence. directions randomized using probability densities polar azimuthal angles: former angle generated single-scattering phase...
A modified Kirchhoff approximation (MKA) is developed for the scattering of light by randomly oriented crystals. The reflected and transmitted near fields are calculated from ray tracing; corresponding far then obtained via vector integral. On shadow side particle, an additional field exactly cancels incident causes forward diffraction. MKA contains a particle size dependence, which not included in optics treatments, satisfactory results can be parameters larger than ten. phase functions...
We consider electromagnetic scattering by a spherical volume sparsely and randomly populated particles of equal size optical properties. The far-field matrix the entire is computed using an exact method approximate method. former direct computer solver Maxwell equations called superposition T-matrix (STMM). latter based on numerical Monte Carlo integration ladder cyclical diagrams appearing in microphysical theory radiative transfer coherent backscattering (RT–CB). quantitative agreement...
There are two widely accepted restrictions on the application of discrete dipole approximation (DDA) in study light scattering by particles comparable to wavelength: (1) when considering dielectric particles, size cells must satisfy condition kd|m|<0.5, where k is wavenumber, d cells, and m complex refractive index constituent material (2) conductive be small enough reproduce sufficiently evolution electromagnetic field skin layer. We examine both DDA applied irregularly shaped show that its...
Abstract BepiColombo has a larger and in many ways more capable suite of instruments relevant for determination the topographic, physical, chemical mineralogical properties Mercury’s surface than carried by NASA’s MESSENGER spacecraft. Moreover, BepiColombo’s data rate is substantially higher. This equips it to confirm, elaborate upon, go beyond MESSENGER’s remarkable achievements. Furthermore, geometry orbital science campaign, beginning 2026, will enable make uniformly resolved...
Abstract We have monitored the Didymos–Dimorphos binary system in imaging polarimetric mode before and after impact from Double Asteroid Redirection Test mission. A previous spectropolarimetric study showed that caused a dramatic drop polarization. Our longer-term monitoring shows polarization of post-impact remains lower than pre-impact even months impact, suggesting some fresh ejecta material at time our observations, either orbit or settled on surface. The slope curve is shallower system,...