Index of acronyms

ADC -- Analogue to Digital Converter

AIDA -- Alis Internal Data Administration

ALIS -- Auroral Large Imaging System , , ,

ANS -- Abisko Scientific Station

ASC -- All-Sky Camera

ASI -- all-sky optical imager

BSC -- Bright Star Catalogue

CC -- control centre

CCD -- Charge Coupled Device

CCH -- CCD camera head ,

CCU -- Camera Control Unit ,

CCU -- CPS Control Unit

CPC -- CPS Control unit

CPS -- Camera Positioning System , ,

CT -- Computer Tomography

CTE -- Charge Transfer Efficiency

DCS -- Double Correlated Sampling

DDS -- Digital Data Storage

DIS -- Doppler Imaging System

DQE -- detective quantum efficiency

EISCAT -- European Incoherent SCATter radar

EPLD -- Erasable, Programmable Logic Device

EPROM -- Erasable Programmable Read-Only Memory

ERP -- Effective Radiated Power

ESD -- electrostatic discharge

FITS -- Flexible Image Transfer System

FoV --  field-of-view

FPN -- Fixed Pattern Noise

FWC -- Filter Wheel Control unit ,

GIP -- General Instrument Platform

GLIP -- Ground-based Low-light Imaging Platform ,

GOSSIP

GPS -- Global Positioning System

HAARP -- High Frequency Active Auroral Research Program facility

HALIS -- Housing for ALIS

HF -- high-frequency

HU -- Housekeeping Unit

IBC -- International Brightness Coefficients

ICC -- Imager Control Computer

ICCD -- Intensified CCD

IGY -- International Geophysical Year

IPC -- Image Processing Computer

IRF -- Swedish Institute of Space Physics , , ,

IT -- Information Technology

LAN -- Local Area Network ,

MART -- Multiplicative Algebraic Reconstruction Technique

MCP -- micro-channel plate

MHD -- Magnetohydrodynamical

NBS -- National Bureau of Standards

NIPR -- National Institute for Polar Research

NIPU -- Near-sensor Interface and Processing Unit , , , , , ,

ntp -- network time protocol

OC -- operations centre

OPERA -- OPERations system for ALIS

PAI -- Portable Auroral Imager ,

pc -- photo-cathode

PCNN -- Pulse Coupled Neural Networks

PDU -- Power Distribution Unit

PLL -- Phase-Locked Loop

PPP -- Point-to-Point Protocol

PPS -- Pulse Per Second

PRNU -- Photo Response Non-Uniformities

PSC -- Polar Stratospheric Clouds PSC , ,

PSC -- polar-stratospheric clouds

PSF -- point spread function

RBNN -- Radial Basis Neural Network

RFI -- Radio Frequency Interference

SC -- Station Computer ,

SEE -- Saturation Equivalent Exposure

SIRT -- Simultaneous Iterative Reconstruction Technique SIRT

SIT -- Selective Imaging Technique

SVD -- Singular Value Decomposition

Swe-ALIS -- the Swedish part of ALIS

TOSCA

UPS -- Uninterruptable Power Supply

UPS -- Uninterrupted Power Supply

WAN -- Wide Area Network (connected to the Internet)

WLI -- WAN/LAN Interface

WTS -- Westward Travelling Surges

Index of notation

$(i,j)$ pixel indices.

$A_{CCD}$ $[m^{2}]$ area of CCD-detector.

$A_{app}$ $[m^{2}]$ effective aperture of the optics.

$A_{i}$ $[m^{2}]$ image area.

$A_{pix}$

$A_{pix}$ $[m^2]$ area of a CCD pixel.

$A_{s}$ $[m^{2}]$ source of area.

$A_{s}$ $[m^{2}]$ source area.

$B_{ADC}$ $[\mu{}V/\mathrm{counts}]$ ADC bit weight ( $90.6~\mu{}V/\mathrm{counts}$).

$C_{abs\lambda{c}}$ $[R/\mathrm{counts}]$ absolute calibration constant.

$C_{abs\lambda{c,binxy}}$ [R/Å] absolute calibration constant with binned pixels.

$E$ Spectral radiant incidence (irradiance).

$G_{CCD}$ $[\mu{}V/e^{-}_{\gamma}]$ CCD output sensitivity.

$G_{P}$ $[1]$ programmable gain setting (5 or 10).

$G_{S}$ $[\mathrm{counts}/e^{-}_{\gamma}]$ imager system gain.

$I$

$I$ $[R]$ column emission rate.

$I_{bg,ij}$ $[R]$ sky background correction.

$I_{cal}$ $[R]$``known'' column emission rate

$I_{ij}$ $[R]$ calibrated pixel-value.

$I_{ls}(\lambda)$ [R/Å] column emission rate of the light standard.

$L$ spectral radiant sterance.

$L_{E}$

$L_{E}$ $[W\,m^{-2}\,\mathrm{sr}^{-1}]$ spectral radiant sterance in energy units.

$M_{FO}$ $[1]$ fibre-optic minification ratio.

$N$

$N_e$ [1] effective index of refraction.

$Q_{EI}$

$Q_{E_{CCD}}$

$T$

$T$

$T'(\lambda)$ $[1]$ normalised filter transmittance function.

$T(\lambda,...)$ $[1]$ transmittance.

$T_f(\lambda)$

$T_{CCD}$

$T_{FO}$

$T_{X}$

$T_{a}$

$T_{dome}(\lambda)$

$T_{f}$

$T_{f}(i,j,\lambda)$ [1] transmittance of the filter.

$T_{o}$

$T_{w}$

$\mathit{CTE}^{N}$

$\mathit{CTE}$ Charge Transfer Efficiency

$\mathit{DN}$ $[\mathrm{counts}]$ digital output.

$\mathit{DN}_{Cij}$ $[\mathrm{counts}]$ uniformly illuminated central pixels of the CCD.

$\mathit{DN}_{DC}$ $[\mathrm{counts}]$ DC-bias-level.

$\mathit{DN}_{SEE}$ $[\mathrm{counts}]$ maximum charge-well capacity.

$\mathit{DN}_{ij}$

$\mathit{DN}_{ij}$ $[\mathrm{counts}]$ digital output.

$\mathit{DN}_{ij}'$

$\mathit{DN}_{ij}'$ $[\mathrm{counts}]$ corrected pixel value.

$\mathit{DN}_{max}$

$\mathit{DN}_{min}$ [counts] minimum ADC output.

$\mathit{DR}$ $[dB]$ Dynamic Range.

$\lambda_{1}\cdots\lambda_{2}$ [Å] filter passband.

$\Delta\lambda$ [Å] filter-bandwidth.

$\Delta\lambda$ [Å] filter passband.

$E_{\gamma_{app}}$ $[\mathrm{photons}\,\mathrm{s}^{-1}\,m^{-2}]$ spectral radiant incidence at the aperture.

$E_{\gamma_{i}}$ $[\mathrm{photons}\,\mathrm{s}^{-1}\,m^{-2}]$ spectral radiant incidence at the image plane.

$\mathit{FR}$ $[\mathrm{images}/s]$ frame rate.

$\mathit{FoV_{o}}$ [angle] optical field-of-view.

$\mathit{FoV_{}}$ field-of-view

$\mathit{FoV_{p}}$ [angle] field-of-view per pixel.

$\mathit{FoV_{p}}$

$\mathit{FoV_{x}}$ [angle] field-of-view in x-direction.

$\mathit{FoV_{y}}$ [angle] field-of-view in y-direction.

$L_{\gamma}$

$L_{\gamma}$

$L_{\gamma}$

$\mathit{NEE}$ Noise Equivalent Exposure.

$\Omega$ $[\mathrm{sr}]$ solid angle.

$\Omega_{ds}$

$\Phi$ $[W]$ radiant flux.

$\Phi_{\gamma_{app}}$ $[\mathrm{photons}/s]$ photon flux.

${Q_{E}}$

${Q_{E}}$ $[e^{-}/\mathrm{photons}]$ quantum efficiency.

$\mathit{SNR}$ $[1]$ signal-to-noise ratio.

$\mathit{SNR}$

$\mathit{SNR}$

$\mathit{SNR}$

$\mathit{SNR}$

$\mathit{SNR}$

$\mathit{SNR}$ of an ICCD $\mathit{SNR}_{ICCD}$

$\alpha$

$\alpha$

$\alpha$-axis

$a_{\phi}$

$a_{\phi}$ [angle] azimuth.

$\beta$

$\beta$

$\beta$

$\beta$-axis

$\mathit{B}_{0}$ $[\mathrm{counts}]$ black-level (or preset bias).

$\mathit{B}_{Lj}$ $[\mathrm{counts}]$ overscan-strip correction.

$\mathit{B}_{\overline{Z}ij}$ $[\mathrm{counts}]$ averaged bias-correction image.

$\mathit{B}_{ij}$ $[\mathit{B}_{]}$ bias (or DC-level).

$\mathit{B}_{q}$ $[\mathrm{counts}]$ quadrant bias.

$\cos^4 \theta$ ``natural vignetting''.

$\cos^4 \theta$

$\mathit{D}_{ij}$ $\mathrm{counts}$ dark-current correction image.

$h_{\theta}$

$\epsilon(\mathbf{r},t,\lambda)$ $[\mathrm{photons}\,\mathrm{m}^{-3}\mathrm{s}^{-1}]$ volume emission rate.

$\eta_{E}$

$\eta_{P}$ $[1]$ phosphor efficiency.

$\mathit{F}_{Mij\lambda}$

$\mathit{F}_{Mij\lambda}$ $[1]$ modelled flat-field correction.

$\mathit{F}_{ij\lambda}$ $[1]$ flat-field correction.

$f_{\char93 }$ $[1]$ f-number.

$\lambda$

$\lambda$ index.

$\lambda$

$\lambda$

$\lambda_{\theta}$

$\lambda_{cw}$

$\lambda_{cw}$ [Å] filter centre wavelength at normal incidence.

$\mathbf{\zeta}$

$n_{e^{-}_{\gamma}}$

$\overline{n}_{e^{-}_{\gamma}}$ $[{e^{-}_{RMS}}]$ average number of photoelectrons.

$\overline{n}_{e^{-}_{\gamma MCP}}$ $[{e^{-}_{RMS}}]$ average number of secondary photoelectrons.

$\overline{n}_{e^{-}_{\gamma{},pc}}$ $[{e^{-}_{RMS}}]$ average number of signal electrons generated by the photo-cathode.

$\overline{n}_{e^{-}_{\gamma{}ij}}$

$n_{e^{-}_{max}}$ $[e^{-}_{}]$ charge well capacity.

$n_{\gamma_{CCD}}$ $[\mathrm{photons}]$ number of photons hitting the CCD.

$n_{\gamma_{i}}$

$n_{\gamma_{i}}$ $[\mathrm{photons}]$ number of photons reaching the image plane.

$n_{\gamma_{pix}}$ $[\mathrm{photons}]$ number of photons hitting an individual pixel.

$\nu$

$\overline{X}$

$\overline{\mathit{DN}}'_{C}$

$\overline{g}$ $[1]$ average MCP gain.

$\overline{g}$

$\overline{g}$

$\langle X \rangle$

$\langle {X} \rangle^{2}$

$\langle n_{e^{-}_{\gamma}} \rangle$ $[{e^{-}_{RMS}}]$ standard deviation of the noise resulting from the photoelectrons.

$\langle n_{e^{-}_{ICCD}} \rangle$ [ ${e^{-}_{RMS}}$] total noise for the ICCD.

$\langle n_{e^{-}_{\gamma}} \rangle$ $[{e^{-}_{RMS}}]$ standard deviation of the noise resulting from the photoelectrons.

$\langle n_{e^{-}_{d}} \rangle$ $[{e^{-}_{RMS}}]$ dark-current noise.

$\langle n_{e^{-}_{p}} \rangle$ $[{e^{-}_{RMS}}]$ pattern noise.

$\langle n_{e^{-}_{r}} \rangle$ $[{e^{-}_{RMS}}]$ standard deviation of the noise floor (or read noise).

$\langle n_{e^{-}_{s}} \rangle$ $[{e^{-}_{RMS}}]$ shot noise.

$\langle n_{e^{-}_{tot}} \rangle$ ${e^{-}_{RMS}}$ total noise.

$\tau_{DCS}$ $[\mu{}s]$ DCS integrator time constant.

$\theta$

$\theta$

$\theta_{max}$ [angle] maximum ray-angle through the filter.

$\theta_{max}$

$t_{\mathit{int}}$

$t_{\mathit{int}}$

$t_{\mathit{int}}$

$t_{\mathit{int}}$ $[s]$ on-chip integration (``exposure'') time.

$t_{int,k}$ $[s]$ integration time for image $k$.

$t_{\mathit{misc}}$ $[s]$ misc. time before the next image can be read.

$t_{\mathit{read}}$ $[s]$ read-out time.

$z_{\theta}$

$z_{\theta}$ zenith-angle.

$c$

$d_{app}$ $[m]$ aperture-stop.

$f$ $[m]$ focal length.

$f_{\char93 fl}$ [1] f-number setting on the front lens.

$h$

$h_{i}$

$h_{s}$

$i$ $[1 \cdots m]$ pixel columns.

$j$ $[1 \cdots n]$ pixel rows.

$k_{MCP}$ microchannel excess noise.

$l$ $[m]$ line of sight.

$r_{i}$

$r_{s}$

$t_{DCS}$ $[\mu{}s]$ DCS integration time.

[R/Å]

$x_{bin}$ $[1]$ binning-factor in the x-direction.

$y_{bin}$ $[1]$ binning factor in the y-direction.

Index

Abisko Scientific Station ANS

absolute calibration constant with binned pixels $C_{abs\lambda{c,binxy}}$ $[R/Ã?Â?]$

absolute calibration constant $C_{abs\lambda{c}}$ $[R/\mathrm{counts}]$

ADC bit weight ( $90.6~\mu{}V/\mathrm{counts}$) $B_{ADC}$ $[\mu{}V/\mathrm{counts}]$

ADCs Analogue to Digital Converters ,

AIDA

AIDA Alis Internal Data Administration ,

ALIS Auroral Large Imaging System , , , , , , ,

Alis Internal Data Administration AIDA

All-Sky Camera ASC

all-sky optical imager ASI

Analogue to Digital Converters ADCs

aniara , , , , ,

ANS Abisko Scientific Station ,

aperture-stop $d_{app}$ $[m]$

area of a CCD pixel $A_{pix}$ $[m^2]$

area of CCD-detector $A_{CCD}$ $[m^{2}]$

arnljot

ASC All-Sky Camera ,

ASI all-sky optical imager ,

Auroral Large Imaging System ALIS , , ,

average MCP gain $\overline{g}$ $[1]$

average number of photoelectrons $\overline{n}_{e^{-}_{\gamma}}$ $[{e^{-}_{RMS}}]$

average number of secondary photoelectrons $\overline{n}_{e^{-}_{\gamma MCP}}$ $[{e^{-}_{RMS}}]$

average number of signal electrons generated by the photo-cathode $\overline{n}_{e^{-}_{\gamma{},pc}}$ $[{e^{-}_{RMS}}]$

averaged bias-correction image $\mathit{B}_{\overline{Z}ij}$ $[\mathrm{counts}]$

Azimuth

azimuth/elevation drive

azimuth $a_{\phi}$ [angle]

bias (or DC-level) $\mathit{B}_{ij}$ $[\mathit{B}_{]}$

bias-frame

bias-pixels

binning factor in the y-direction $y_{bin}$ $[1]$

binning-factor in the x-direction $x_{bin}$ $[1]$

black-level (or preset bias) $\mathit{B}_{0}$ $[\mathrm{counts}]$

Bright Star Catalogue BSC

BSC Bright Star Catalogue ,

calibrated pixel-value $I_{ij}$ $[R]$

camera control unit ,

Camera Control Unit CCU ,

Camera Positioning System CPS , ,

Camera stand

CC control centre ,

CCD camera head CCH ,

CCD Charge Coupled Device ,

CCD output sensitivity $G_{CCD}$ $[\mu{}V/e^{-}_{\gamma}]$

CCH CCD camera head , , ,

CCU

CCU Camera Control Unit , , ,

CCU CPS Control Unit ,

Charge Coupled Device CCD

Charge Transfer Efficiency $\mathit{CTE}$

charge well capacity $n_{e^{-}_{max}}$ $[e^{-}_{}]$

column emission

column emission rate

column emission rate of the light standard $I_{ls}(\lambda)$ $[R/Ã?Â?]$

column emission rate $I$ $[R]$

Computer Tomography CT

control centre

control centre CC

corrected pixel value $\mathit{DN}_{ij}'$ $[\mathrm{counts}]$

CPC

CPC CPS Control unit ,

CPS

CPS Camera Positioning System , , , , ,

CPS Control Unit CCU

CPS Control unit CPC

CT Computer Tomography ,

dark-current correction image $\mathit{D}_{ij}$ $\mathrm{counts}$

dark-current noise

dark-current noise $\langle n_{e^{-}_{d}} \rangle$ $[{e^{-}_{RMS}}]$

DC-bias-level $\mathit{DN}_{DC}$ $[\mathrm{counts}]$

DCS

DCS Double Correlated Sampling ,

DCS integration time $t_{DCS}$ $[\mu{}s]$

DCS integrator time constant $\tau_{DCS}$ $[\mu{}s]$

DDS Digital Data Storage ,

detective quantum efficiency DQE

Digital Data Storage DDS

digital output $\mathit{DN}$ $[\mathrm{counts}]$

digital output $\mathit{DN}_{ij}$ $[\mathrm{counts}]$

digital-output

DIS Doppler Imaging System , , ,

Doppler Imaging System DIS ,

Double Correlated Sampling DCS

DQE detective quantum efficiency ,

Dynamic Range $\mathit{DR}$ $[dB]$

effective aperture of the optics $A_{app}$ $[m^{2}]$

effective index of refraction $N_e$ [1]

effective quantum yield

Effective Radiated Power ERP

EISCAT

EISCAT European Incoherent SCATter radar ,

electron multiplication noise

electrostatic discharge ESD

EPLD Erasable, Programmable Logic Device ,

EPROM

EPROM Erasable Programmable Read-Only Memory ,

Erasable Programmable Read-Only Memory EPROM

Erasable, Programmable Logic Device EPLD

ERP Effective Radiated Power ,

ESD electrostatic discharge ,

European Incoherent SCATter radar EISCAT

f-number setting on the front lens $f_{\char93 fl}$ [1]

f-number $f_{\char93 }$ $[1]$

Fabry-Perot filters

fibre-optic minification ratio $M_{FO}$ $[1]$

field-of-view in x-direction $\mathit{FoV_{x}}$ [angle]

field-of-view in y-direction $\mathit{FoV_{y}}$ [angle]

field-of-view per pixel $\mathit{FoV_{p}}$ [angle]

field-of-view $\mathit{FoV_{}}$

filter centre wavelength at normal incidence $\lambda_{cw}$ [Å]

filter passband $\lambda_{1}\cdots\lambda_{2}$ [Å]

filter passband $\Delta\lambda$ [Å]

Filter Wheel Control unit FWC

filter-bandwidth $\Delta\lambda$ [Å]

Filter-Wheel Control unit FWC

FITS

FITS Flexible Image Transfer System ,

Fixed Pattern Noise FPN

flat-field correction $\mathit{F}_{ij\lambda}$ $[1]$

Flexible Image Transfer System FITS

focal length $f$ $[m]$

FPN Fixed Pattern Noise ,

FPS

Frame rate

frame rate $\mathit{FR}$ $[\mathrm{images}/s]$

frequency

FWC ,

FWC Filter Wheel Control unit ,

FWC Filter-Wheel Control unit ,

General Instrument Platform GIP

geometrical calibration

GIP General Instrument Platform ,

GLIP Ground-based Low-light Imaging Platform , , ,

Global Positioning System GPS

GOSSIP

GPS Global Positioning System ,

Ground-based Low-light Imaging Platform GLIP ,

HAARP High Frequency Active Auroral Research Program facility ,

HALIS Housing for ALIS ,

HENRIK ,

HF high-frequency ,

HF pump-enhanced airglow

High Frequency Active Auroral Research Program facility HAARP

high-frequency HF

high-speed link

Housekeeping Unit

Housekeeping Unit HU

Housing for ALIS HALIS

http

HU Housekeeping Unit ,

ICC Imager Control Computer ,

ICCD Intensified CCD ,

IGY International Geophysical Year ,

image area $A_{i}$ $[m^{2}]$

Image Processing Computer IPC

image-intensifier

Imager Control Computer ICC

imager system gain $G_{S}$ $[\mathrm{counts}/e^{-}_{\gamma}]$

index $\lambda$

Information Technology IT

integrating sphere

integration time

integration time for image $k$ $t_{int,k}$ $[s]$

Intensified CCD ICCD

interference filter

International Brightness Coefficients IBC

International Geophysical Year IGY

IPC Image Processing Computer ,

IRF , , , , ,

IRF Swedish Institute of Space Physics , , ,

IT Information Technology ,

LAN Local Area Network , , ,

line of sight $l$ $[m]$

Local Area Network LAN ,

Magnetohydrodynamical MHD

MART Multiplicative Algebraic Reconstruction Technique ,

maximum ADC output

maximum charge-well capacity $\mathit{DN}_{SEE}$ $[\mathrm{counts}]$

maximum ray-angle through the filter $\theta_{max}$ [angle]

MCP micro-channel plate ,

mean value

MHD Magnetohydrodynamical ,

micro-channel plate MCP

microchannel excess noise $k_{MCP}$

mima , , ,

minimum ADC output $\mathit{DN}_{min}$ [counts]

misc. time before the next image can be read $t_{\mathit{misc}}$ $[s]$

modelled flat-field correction

modelled flat-field correction $\mathit{F}_{Mij\lambda}$ $[1]$

Multiplicative Algebraic Reconstruction Technique MART

narrow-band interference filters

National Bureau of Standards NBS

National Institute for Polar Research NIPR

NBS National Bureau of Standards ,

Near-sensor Interface and Processing Unit NIPU

network time protocol ntp

NIPR National Institute for Polar Research

NIPU , , , , , , , , , ,

NIPU Near-sensor Interface and Processing Unit ,

Noise

Noise Equivalent Exposure $\mathit{NEE}$

normalised filter transmittance function $T'(\lambda)$ $[1]$

ntp network time protocol ,

ntpd

number of photons hitting an individual pixel $n_{\gamma_{pix}}$ $[\mathrm{photons}]$

number of photons hitting the CCD $n_{\gamma_{CCD}}$ $[\mathrm{photons}]$

number of photons reaching the image plane

number of photons reaching the image plane $n_{\gamma_{i}}$ $[\mathrm{photons}]$

number of transfers

OC Operations Centre ,

on-chip integration (``exposure'') time $t_{\mathit{int}}$ $[s]$

OPERA OPERations system for ALIS ,

operations centre

Operations Centre OC

OPERations system for ALIS OPERA

optical field-of-view $\mathit{FoV_{o}}$ [angle]

overscan-strip ,

overscan-strip correction $\mathit{B}_{Lj}$ $[\mathrm{counts}]$

PAI Portable Auroral Imager , , ,

parsifal , ,

passband

pattern noise $\langle n_{e^{-}_{p}} \rangle$ $[{e^{-}_{RMS}}]$

PCNN Pulse Coupled Neural Networks ,

PDU Power Distribution Unit ,

Phase-Locked Loop PLL

phosphor efficiency $\eta_{P}$ $[1]$

Photo Response Non-Uniformities PRNU

photo-cathode

photo-cathode dark-current noise

photo-cathode $\mathit{pc}$

photometry

photon flux $\Phi_{\gamma_{app}}$ $[\mathrm{photons}/s]$

photon-noise

pixel columns $i$ $[1 \cdots m]$

pixel indices $(i,j)$

pixel rows $j$ $[1 \cdots n]$

Planck's constant

PLL Phase-Locked Loop ,

point spread function PSF

Point-to-Point Protocol ppp

Polar Stratospheric Clouds PSC , ,

polar-stratospheric clouds

Portable Auroral Imager PAI ,

Power Distribution Unit PDU

ppp

ppp Point-to-Point Protocol ,

PPS Pulse Per Second ,

PRNU Photo Response Non-Uniformities ,

programmable gain setting (5 or 10) $G_{P}$ $[1]$

PSC

PSC Polar Stratospheric Clouds , , , , ,

PSF point spread function ,

Pulse Coupled Neural Networks PCNN

Pulse Per Second PPS

quadrant bias $\mathit{B}_{q}$ $[\mathrm{counts}]$

quantum efficiency ${Q_{E}}$ $[e^{-}/\mathrm{photons}]$

radames

Radial Basis Neural Network RBNN

radiance

radiant flux $\Phi$ $[W]$

Radio Frequency Interference RFI

radiometric unit for the aurora and airglow

radiometry

Rayleigh

Rayleighs/�ngström

RBNN Radial Basis Neural Network ,

read noise

read-noise

read-out time $t_{\mathit{read}}$ $[s]$

reference pixels

reference-pixels

Removing the instrument signature

RFI Radio Frequency Interference ,

rigoletto

root-mean-square electrons

Saturation Equivalent Exposure SEE

SC Station Computer , , ,

SEE Saturation Equivalent Exposure ,

Selective Imaging Technique SIT

shot noise $\langle n_{e^{-}_{s}} \rangle$ $[{e^{-}_{RMS}}]$

Signal-to-noise ratio

signal-to-noise ratio of an ICCD

signal-to-noise ratio $\mathit{SNR}$ $[1]$

Simultaneous Iterative Reconstruction Technique SIRT

Singular Value Decomposition SVD

SIRT Simultaneous Iterative Reconstruction Technique ,

SIT Selective Imaging Technique ,

sky background correction $I_{bg,ij}$ $[R]$

solid angle of the lens aperture as seen from the source

solid angle $\Omega$ $[\mathrm{sr}]$

source area $A_{s}$ $[m^{2}]$

source of area $A_{s}$ $[m^{2}]$

spectral radiant incidence at the aperture $E_{\gamma_{app}}$ $[\mathrm{photons}\,\mathrm{s}^{-1}\,m^{-2}]$

spectral radiant incidence at the image plane $E_{\gamma_{i}}$ $[\mathrm{photons}\,\mathrm{s}^{-1}\,m^{-2}]$

Spectral radiant incidence (irradiance) $E$

spectral radiant sterance ,

spectral radiant sterance in energy units $L_{E}$ $[W\,m^{-2}\,\mathrm{sr}^{-1}]$

spectral radiant sterance in quantum units

spectral radiant sterance $L$

speed of light

ssh

standard deviation

standard deviation of the noise floor (or read noise) $\langle n_{e^{-}_{r}} \rangle$ $[{e^{-}_{RMS}}]$

standard deviation of the noise resulting from the photoelectrons $\langle n_{e^{-}_{\gamma}} \rangle$ $[{e^{-}_{RMS}}]$

station computer SC ,

SVD Singular Value Decomposition ,

Swe-ALIS the Swedish part of ALIS ,

Swedish Institute of Space Physics IRF ,

Swedish part of ALIS Swe-ALIS

telnet

threshold of detection

tosca ,

total noise for the ICCD $\langle n_{e^{-}_{ICCD}} \rangle$ [ ${e^{-}_{RMS}}$]

total noise $\langle n_{e^{-}_{tot}} \rangle$ ${e^{-}_{RMS}}$

Transmittance

transmittance of the atmosphere

transmittance of the filter $T_{f}(i,j,\lambda)$ [1]

transmittance $T(\lambda,...)$ $[1]$

uniformly illuminated central pixels of the CCD $\mathit{DN}_{Cij}$ $[\mathrm{counts}]$

Uninterruptable Power Supply UPS

Uninterrupted Power Supply UPS

UPS Uninterruptable Power Supply ,

variance

verdi ,

vignetting

volume emission rate $\epsilon(\mathbf{r},t,\lambda)$ $[\mathrm{photons}\,\mathrm{m}^{-3}\mathrm{s}^{-1}]$

Vorticity

WAN Wide Area Network (connected to the Internet) ,

WAN/LAN Interface consisting of the WAN-Interface, a router, a switch and possibly also a firewall WLI

wavelength ,

Westward Travelling Surges WTS

Wide Area Network (connected to the Internet) WAN

WLI WAN/LAN Interface consisting of the WAN-Interface, a router, a switch and possibly also a firewall ,

WTS Westward Travelling Surges

Zenith angle

zenith-angle $z_{\theta}$

zero-exposure