Space Instrumentation
Part 1/2
ELEC-E4220 (5 cr)
Teacher: Esa Kallio
Visitors: Prof. Eija Tanskanen, Dr. Andrew
Dimmock, PhD student Antti Näsilä
Assistant: Pyry Peitso
Aalto University
School of Electrical Engineering
Department of Radio Science and Engineering
SPACE REGIONS
SPACE
INSTRUMENTS
Theory
[data]
4. THE SUN
Multi wavelength camera
emission and absorption
[SOHO, Stereo, SDO]
velocity distribution function
[ACE, SOHO, etc.]
Ohm’s law, reconnection
[ACE, DSCOVR, etc.]
Particle instrument
5. SOLAR WIND
Magnetometer
6. MAGNETOSPERE
Radio instrument
1. IONOSPHERE
Langmuir probe
2. ATMOSPHERE
High energy particle instr.
3. SURFACE
NASA
4.10.2016
Radar & ionosonde
Magnetometers, cameras
Space Instrumentation, Aalto University, Esa Kallio
waves and their propagation
[Suomi 100 satellite, etc.]
Debye layer
[Aalto-2 satellite, etc.]
surface charging
[Aalto-1 satellite, etc.]
ionosphere
[EISCAT, ionosondes, etc.]
2
ESA KALLIO
OUR ROADMAP
This week
1.
Remote sensing instruments
- Aasi/Aalto-1 (Antti Näsilä)
2.
Theory
- Emission & absorption spectra
- Motion of molecules
- Zeeman effect
- Charge exchange
3.
Regions
- Surfaces of Solar System bodies
- Atmospheres and exospheres
- Sun, Mars, Mercury, the Moon
4.
Examples
- Missions: MEX, MAVEN, Bepi Colombo, SDO
- Instruments: SPICAM/MEX, Phebus/BepiColombo
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
3
Online material
http://solarsystem.nasa.gov/basics/bsf12-1.php
http://www.hist-geo-space-sci.net/6/3/2015/hgss-6-3-2015.pdf
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
4
G E N E R A L I T I ES O N S PAC E S P EC T RO M E T RY
• Importance of explore all parts of the spectrum
•  ray
• X ray
• EUV/UV [10-400 nm]
• Visible [400-700 nm]
• IR [700-1500 nm]
• Sub-mm to radio waves
Planetary space optics:
Surface, atmosphere, upper atmosphere, exosphere
Space Instrumentation, Aalto University, Esa Kallio
4.10.2016
 ESA
5
Extreme ultraviolet emission
Extreme ultraviolet (EUV or XUV) emission: 10 - 120 nm (100 - 120 Angstrom)
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
6
THEORY
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
7
EM wave – molecule interaction
http://www.wag.caltech.edu/home/jang/genchem/infrared.htm
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
8
EM wave – molecule interaction
http://www.wag.caltech.edu/home/jang/genchem/infrared.htm
4.10.2016
https://sites.google.com/site/chem1403/molecular-motion
Space Instrumentation, Aalto University, Esa Kallio
9
IR and molecular motion
A molecule of water is polar because of the unequal
sharing of its electrons in a "bent" structure. A
separation of charge is present with negative charge in
the middle (red shade), and positive charge at the ends
(blue shade).
To excite a rotational transition, the
molecule must have a permanent
dipole moment.
Molecular vibrations that change
the dipole moment are IR active.
https://sites.google.com/site/chem1403/molecular-motion
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
10
EUV – atom/molecule interaction:
a planetary atmosphere
• The colors indicate where the solar
EUV radiation is absorbed in the
terrestrial atmosphere as a function
of wavelength and height. It also
shows the vertical temperature
profile of the atmosphere and how
much it changes during the 11 year
solar cycle. All of the solar EUV
energy is absorbed above 95 km
• The EUV radiation heats the
atmosphere to nearly to 550 C at
solar minimum and 900 C at solar
maximum
• The EUV radiation ionizes the upper
atmosphere
• The ionization process creates
electrons which form the ionosphere
• The ionosphere refracts (bends) and
reflects radio signals
• Changes in the ionosphere will
change how radio waves are
reflected and transmitted
• This directly impacts many systems
and technologies such as radio
communication and navigation
http://www.nasa.gov/mission_pages/sdo/multimedia/20110907_briefing_materials.html
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
Credit: R. Viereck/SWPC/NOAA
11
Infrared spectroscopy & Microwaves
“Because the IR spectrum of each molecule is unique, it can serve as a signature or
fingerprint to identify the molecule.
This feature, along with the fact that it is a non-destructive technique, have made
infrared spectroscopy a valuable method in chemical analysis.
Areas in which it is used extensively include pharmaceutical analysis, quality control
in industrial processes, environmental chemistry, geology and astronomy.”
“Microwave radiation is even less energetic than infrared radiation. It cannot excite
electrons in molecules, nor can it excite vibrations; it can only cause molecules to
rotate.
Microwave ovens are tuned to the frequency that causes molecules of water to rotate,
and the ensuing friction causes heating of water-containing substances.”
http://www.wag.caltech.edu/home/jang/genchem/infrared.htm
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
12
Absorption and emission spectrum
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
13
Example of atmospheric absorption spectrum
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
14
Spectra of Earth like Planet
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
15
Zeeman effect and magnetograms
Zeeman effect: splitting a spectral line into several components in the
presence of a static magnetic field
=> Effect can be used to measure the magnitude and the direction of the
magnetic field from where the emission is coming from.
https://en.wikipedia.org/wiki/Zeeman_effect
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
16
Observing Spectra - line splitting from the
Zeeman effect
Strong B-field splits spectral
lines according to strength
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
17
Remote sensing by using Energetic Neutral
Atoms, ENAs
Generally neutral
atoms in space are
formed very cold.
However, charge
exchange with an
energetic plasma
population can
create energetic
neutrals which travel
in ballistic
trajectories rather
than being trapped
along magnetic
fields.
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
18
ENA instrument: An exmaple
Astronautics Now
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
19
ENA imaging
Are present everywhere in space, but are sourced most readily from regions with high densities of
neutrals and ions.
Useful for imaging the plasmasphere and ring current at Earth, and the interaction of the atmosphere
of the rings of Saturn with Saturn’s magnetospheric plasma
4.10.2016
Space Instrumentation, Aalto University, Esa Kallio
20