ObsTechOutline

sunglowcitrineΠολεοδομικά Έργα

15 Νοε 2013 (πριν από 3 χρόνια και 11 μήνες)

89 εμφανίσεις

90 minutes


54 to 90 viewgraphs!


Observational Techniques


Outline


Brief review of
spectral ranges

from solar context


Atomic line

Thermal

x
-
rays


Nonthermal
x
-
rays

Radio


coherent

Incoherent

(thermal and nonthermal)

Nuclear line


Physics of photon i
nteractions at progressively higher energies

Refraction

Reflection

Normal reflection from thin layers

Grazing incidence

Photoelectric effect

Compton scattering

Pair production

Nuclear
elastic and inelastic scattering and
interactions


Imaging techniques (e
xamples, strengths, weaknesses)


Conventional reflecting or refracting optics

(pixilated detectors)


Normal incidence


Grazing incidence (Wolter types)

Normal incidence (thin films)

Compton telescopes

Collimation techniques


Summary diagram of above


prop
erties vs energy.




will concentrate on collimation from here on



Types of collimation telescopes (examples, strengths, weaknesses)

Soller
collimation

URA’s

Spatial modulation

Time modulation


Imaging Considerations


Detector Background /noise



Thermal

limitations



Radiation

& particles


Scattered light



Energy / wavelength resolution and range


Angular resolution and field of view


Sensitivity


source limited vs background
-
limited


Source characteristics



Morphologically rich



Point source locati
ons



Simple multicomponent images



Solar
-
specific

tradeoffs

(different from

nonsolar,
choice is
usually spacecraft
-
driven
, examples
)


Specifics of rotating modulation collimators


Early examples
, nonsolar, Hinotori, HEIDI, RHESSI


RHESSI imaging (ideal
ized perspective


reality is covered in practicum)


Animation of time
-
modulation


How modulation changes with source location, etc.


Hardware configuration


Motivation for grid pitch selection


Perspectives on imaging



Backprojection



PRF of individual

collimators



Visibilities


Overview of

imaging algorithms


Performance, strengths, weaknesses


Future


Collimator adaptation to other spacecraft (Solar Orbiter, Sentinels)


Grazing incidence


currently limited to ‘intermediate resolution’, lower energi
es

-

might be useful in lower energy, background limited situations.