Symbol | Explanation | |
area | ||
area of primary mirror | ||
area of aperture | ||
aperture | ||
generic constant | ||
offset of linear regression in the reset interval correction | ||
slope of linear regression in the reset interval correction | ||
, | first order correction on point source spectral response function | |
, | first order signal corrections for PHT-S chopped observations | |
, | coefficients for signal dependent PHT-S correction | |
flux density conversion factor | ||
empirical asymmetry factor for chopper offset | ||
coefficients for chopper offset correction | ||
surface brightness | ||
mean brightness | ||
background surface brightness | ||
accumulated sum of first n sky measurements to | ||
mean brightness | ||
generic constant | ||
speed of light = 299792500 ms in OLP | ||
generic constant | ||
generic constant | ||
, | constants | |
statistic | ||
detector capacitance | ||
idem for detector | ||
C1 | constant for transmission of the whole optical path for a given filter | |
assuming as reference spectrum.The effective size | ||
of the primary mirror; reflection losses, filter transmission, spectral | ||
response of the detector, etc. are included | ||
spectral response function for pixel i | ||
average spectral response function for a point source | ||
spectral response of pixel i for a point source p corrected for chopped c | ||
signal losses | ||
average spectral response function for PHT-S staring observations | ||
spectral response function for pixel i corrected for chopped signal loss | ||
PHT-S averaged chopped spectral response function for a point source | ||
integration capacitance associated with detector P1, P2 or P3, | ||
point source responsivity for PHT-S pixel | ||
extended source responsivity for PHT-S pixel | ||
height of source peak (background subtracted) | ||
diameter of Airy disk | ||
diameter of aperture for PHT-P, side length of the array for PHT-C | ||
Dec | declination | |
DI | selected offset data word (0...4095) | |
fixed voltage offset for CRE | ||
exposure time | ||
e(i,j) | contribution from nth sky sample to exposure time | |
accumulated exposure time | ||
(i,j) | sum of first n sky pointings | |
(i,j) | total exposure time of image | |
filter | ||
flux density | ||
point spread function fraction for filter f | ||
entering the field aperture in case of PHT-P or falling onto the | ||
array in case of PHT-C | ||
intensity function of a point source entering the aperture | ||
fraction of the telescope point spread function falling into a given | ||
aperture for PHT-P or onto the full array for PHT-C | ||
idem for a given aperture | ||
idem for the entire detector array | ||
idem for a given pixel | ||
fraction of point spread function at the reference wavelength | ||
wavelength dependent beam profile | ||
inside the aperture or pixel | ||
coverage factor | ||
flat-field correction for pixel | ||
flux density in frequency units unless explicitly specified | ||
(i,k) | flux for pixel i at raster point k | |
source+background flux | ||
source+background flux | ||
background flux | ||
background flux | ||
source flux with psf correction for point source | ||
(i) | flux density in wavelength units for pixel | |
flux density of source at specific wavelength | ||
source flux density for an assumed spectral energy distribution | ||
(flux density at reference wavelength) | ||
flux density at centre wavelength of filter | ||
flux density for applied SED | ||
flux density quoted in AAR | ||
flux density in frequency range | ||
flux density in wavelength range | ||
source flux density for an assumed spectral energy distribution | ||
at reference wavelength | ||
weighting function for correction | ||
weight factors related to correction (i,S,t) | ||
goodness of fit | ||
gain | ||
offset gain | ||
signal gain | ||
Planck constant | ||
heating power of FCS | ||
linearisation correction for signal S | ||
idem, for filter , detector pixel , and signal | ||
pixel index, integer counter | ||
Surface brightness in wavelength units unless explicitly stated | ||
surface brightness based on monochromatic point source flux density | ||
surface brightness of (extended) source in filter f, assuming | ||
(i) | surface brightness of a given detector array element i (of PHT-S) | |
IBP | in-band power in W | |
step flag, for chopper position within a chopper cycle | ||
integer counter | ||
chopper cycle number | ||
raster point number in one direction | ||
Boltzmann's constant | ||
colour correction | ||
constant | ||
(SED) | colour correction factors for applied SED | |
length or integer counter | ||
raster point number in one direction | ||
length | ||
map size in RA | ||
map size in Dec | ||
mean pixel value used to convert into the correct units | ||
number of raster steps along a raster leg | ||
median of s per chopper unit | ||
number of columns of raster | ||
n | integer counter | |
n | minimum number of image pixels in RA to cover raster area | |
n | minimum number of image pixels in Dec to cover raster area | |
n | index representing the dwell time in the calibration files | |
n | number of detector pixels | |
N | integer counter | |
number of iterations for ramp deglitching | ||
minimum number of readouts per ramp | ||
sigma value to identify outliers in ramp deglitching | ||
number of chopper units | ||
number of ramps per chopper plateau | ||
total number of readouts | ||
actual number of ramps per chopper plateau in the telemetry, is derived | ||
from N' = N/DAT_RED where N is the commanded number of | ||
ramps per chopper plateau and DAT_RED is the applied data reduction | ||
factor | ||
number of fine grid positions that fall within the detector footprint | ||
total number of fine grid positions that fall within a pixel | ||
cirrus confusion noise | ||
galaxy confusion noise | ||
power in W | ||
in-band power for filter f' and FCS heating power h in mW as obtained from | ||
FCS power tables, for PHT-P in Wmm, | ||
for PHT-C in W/pixel | ||
source power | ||
power measured on pixel if line is centred | ||
power measured on adjacent pixel if line is centred | ||
power measured on pixel if line is centred between pixels | ||
(h) | in-band power for filter f and FCS heating power h | |
in-band power of celestial calibrator | ||
in-band power for filter f in aperture a | ||
in-band power for filter f and pixel | ||
maximum commandable power on FCS | ||
in-band power of on-source position | ||
in-band power of off-source position | ||
in-band power of source only | ||
peak (source) power value | ||
background power value | ||
in-band power on the detector from the FCS due to heating power h | ||
in-band power obtained from the source | ||
in-band power for given FCS heating power h | ||
constant | ||
detection limit in multiples of | ||
quaternion | ||
quarternion that defines the position of the PHT central field of view for | ||
a given raster point in the J2000 inertial frame | ||
defines the J2000 pointing of the ISO star tracker | ||
defines the raster point relative to the raster centre of the scan | ||
describes misalignment between the star tracker and the quadrant star | ||
sensor (QSS) | ||
describes the QSS to instrument aperture alignment | ||
gives the fine pointing correction to the star tracker calibration | ||
quarternions representing the rotations of the detector origin with | ||
respect to a given raster point, assuming perfect alignment between | ||
chopper and spacecraft y-axis | ||
chopper quaternion | ||
constant | ||
responsivity | ||
average relative system response derived from a bandpass | ||
detector responsivity | ||
(i) | detector responsivity of pixel i | |
default detector responsivity | ||
responsivity for each pixel of a C detector | ||
responsivity of pixel obtained from FCS | ||
system response at specific wavelength | ||
sensor resistance | ||
constant in resistance | ||
harness resistance | ||
EEU shunt resistor in parallel to sensor | ||
measured responsivity of pixel relative to default responsivity | ||
signal in V/s | ||
source signal | ||
signal at time t | ||
pairwise differences between V(k) and V(k+1) | ||
slope for ramp j | ||
signal taken with reset interval RI and data reduction rate DAT_RED | ||
signal after orbital dependent dark correction | ||
initial signal | ||
((t)) | orbit dependent dark correction | |
signal before signal linearisation | ||
signal after signal linearisation | ||
signal | ||
average of valid signals per chopper plateau | ||
difference signals of consecutive readouts | ||
generic pattern | ||
source signal determined via generic pattern | ||
source signal determined via generic pattern, corrected for losses due to | ||
chopper modulation | ||
(x) | source signal for chopper cycle k | |
(X) | given set of powers | |
weighted mean signal for FCS measurement | ||
FCS signal per chopper plateau | ||
image pixel size | ||
nominal uncertainty of fit | ||
uncertainty of fit | ||
signal | ||
linearised difference signal (from chopped measurement) | ||
linearised difference signal, corrected for losses due to chopper | ||
modulations | ||
, S | on- and off-source signals | |
signal for pixel i at raster point k | ||
measured signal of calibrator | ||
measured dark FCS signal (stray light) | ||
signal of FCS measurement in filter f' | ||
linearised source signal (PHT-P) after dark signal subtraction | ||
linearised source signal (PHT-C) after dark signal subtraction | ||
signal transient of pixel i at time t | ||
orbit dependent dark signals | ||
size | ||
side length of (square) fine grid image pixel | ||
side length of square detector pixel | ||
time in s | ||
time at midpoint of a given ramp | ||
time at first readout of a given ramp | ||
chopper dwell time | ||
measurement time | ||
reset interval time | ||
chopper plateau time | ||
dwell time | ||
temperature in K | ||
EEU temperature | ||
reflection losses on optical elements | ||
tmd | telemetry data value | |
maximum value of telemetry word (=4096) | ||
TOL | voltage for chopper deflection calibration | |
RA | right ascension | |
chopper unit | ||
uncertainty | ||
(i,j) | mean brightness uncertainty contribution from nth sky sample | |
voltage in V | ||
voltage for chopper deflection calibration | ||
voltage for chopper deflection calibration | ||
voltage for chopper deflection calibration | ||
voltage for chopper deflection calibration | ||
CRE output voltage | ||
GAIN dependent offset voltage | ||
uncertainty | ||
(i,j) | accumulated mean brightness uncertainty | |
(i,j) | brightness uncertainty from rms | |
voltage in V | ||
voltage corresponding to readout k | ||
voltage | ||
weight | ||
weight function for PHT-S chopped measurements | ||
statistical weight of each signal obtained from its associated statistical | ||
uncertainty | ||
distance or coordinate | ||
margin around raster in m direction | ||
margin around raster in n direction | ||
angular x coordinate of the image pixel origin | ||
data word for focal plane chopper position | ||
distance or coordinate | ||
chopper deflection | ||
angular y coordinate of the image pixel origin | ||
distance or coordinate | ||
spacecraft z-offset |