SCTS-01#
The design model can be found here: SCTS-design.
Parameters shown in bold and italics are specific to each telescope. Parameters without emphasis are inherited from the design model.
Structure#
Parameter Name |
Parameter Version |
Values |
Short Description |
|---|---|---|---|
array element position ground |
2.0.0 |
-0.0 m, -0.0 m, 24.0 m |
Ground coordinate position of an array element. |
array element position utm |
2.0.0 |
366822.0 m, 7269466.0 m, 2162.0 m |
UTM coordinate position of an array element. |
axes offsets |
1.0.0 |
160.0 cm, 0.0 cm |
Geometric offsets to be used in case that the azimuth, altitude, and optical axes do not intersect at the reference point. |
camera body diameter |
1.0.0 |
154.0 cm |
Diameter of camera body (used to account for effects of shadowing). Flat-to-flat for square and hexagonal shapes. |
camera body_shape |
1.0.0 |
0 |
Camera body shape parameter (used to account for effects of shadowing). |
camera depth |
1.0.0 |
0.0 cm |
Depth of the camera body (used to account for effects of shadowing). |
camera filter incidence angle |
1.0.0 |
Distribution of incidence angle on the camera filter. |
|
dish_shape length |
1.0.0 |
0.0 cm |
Dish curvature length, best equal to focal length. |
effective focal length |
1.0.0 |
558.31 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm |
Effective focal length. Only to be used for image analysis, has no effect on the simulation. |
fake mirror list |
1.0.0 |
Fake mirror list to be used for camera efficiency calculations (‘testeff’ program). |
|
focal length |
1.0.0 |
558.63 cm |
Nominal overall focal length of the entire telescope. |
focal surface parameters |
1.0.0 |
1.16667 cm, -0.8327 cm, 4.995 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm |
Defines the position of the focal surface along the optical axis and its off-axis shape. |
focal surface ref_radius |
1.0.0 |
558.63 cm |
The length scale to which the focal_surface_parameters apply. |
focus offset |
1.0.0 |
0.2 cm, 0.0 deg, 0.0 , 0.0 |
Distance of the starlight focus from the camera pixels (light guides) entry. |
mirror align random distance |
1.0.0 |
0.0 cm |
Gaussian r.m.s. spread of random fluctuations in the aligned mirror distance from the focus. |
mirror align random horizontal |
1.0.0 |
0.0 deg, 0.0 deg, 0.0 , 0.0 |
Gaussian r.m.s. spread of random fluctuations of the mirror alignment angle with respect to nominal alignment in the horizontal component. |
mirror align random vertical |
1.0.0 |
0.0 deg, 0.0 deg, 0.0 , 0.0 |
Gaussian r.m.s. spread of random fluctuations of the mirror alignment angle with respect to nominal alignment in the vertical component. |
mirror class |
1.0.0 |
2 |
Parameter to control the type of mirror used (DC, parabolic or SC). |
mirror degraded reflection |
1.0.0 |
1.0 |
Mirror degradation factor (wavelength independent). |
mirror focal length |
1.0.0 |
0.0 cm |
Standard focal length of mirror tiles. |
mirror offset |
1.0.0 |
-203.0 cm |
Offset of mirror back plane from fixed point of telescope mount or from the altitude rotation axis, along the direction of the optical axis. |
mirror reflection random angle |
1.0.0 |
0.025 deg, 0.0 , 0.0 deg |
Gaussian r.m.s. spread of random fluctuations of microscopic reflection angles due to small-scale surface deviations. |
mirror reflectivity |
1.0.0 |
Mirror reflectivity measured directly on the facet as function of wavelength. For dual mirror telescopes without explicit reflectivity table given for the secondary, this reflectivity given here is applied twice. |
|
parabolic dish |
1.0.0 |
0 |
Parabolic dish shape is used. |
pixels parallel |
1.0.0 |
3 |
Parameter controlling the orientation of the pixels, setting it to be aligned with the optical axis or the focal surface normal. |
primary mirror diameter |
1.0.0 |
966.38 cm |
The outer diameter of the primary reflector. Used only in case mirror_list is not defined (i.e., mirror_list=none). |
primary mirror hole diameter |
1.0.0 |
438.66 cm |
The diameter of any non-reflective part of the primary mirror. |
primary mirror parameters |
1.0.0 |
0.0 cm, 0.111112 cm, -0.00698726 cm, -0.00206487 cm, -0.00689219 cm, 0.0301911 cm, -0.119762 cm, 0.319791 cm, -0.602077 cm, 0.777846 cm, -0.661167 cm, 0.333439 cm, -0.0764291 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm |
Parameters for a polynomial defining the position of the primary mirror along the optical axis and its shape. |
primary mirror_ref radius |
1.0.0 |
558.63 cm |
The length scale to which the primary_mirror_parameters apply. |
primary mirror segmentation |
1.0.0 |
Definition of segments or segment groups of the primary reflector. |
|
random focal length |
1.0.0 |
0.0 cm, 0.0 cm |
The spread of random fluctuations in mirror focal lengths. |
secondary mirror baffle |
1.0.0 |
680.17 cm, 780.5 cm, 284.48 cm, 2.64 cm, 0.0 cm |
Defines a baffle around the secondary mirror to keep NSB light from falling directly onto the camera. |
secondary mirror degraded reflection |
1.0.0 |
1.0 |
Mirror degradation factor for the secondary mirror (wavelength independent). |
secondary mirror diameter |
1.0.0 |
541.66 cm |
The outer diameter of the secondary reflector. Used only in case mirror_list is not defined (i.e., mirror_list=none). |
secondary mirror hole diameter |
1.0.0 |
78.9 cm |
The diameter of any non-reflective part of the secondary mirror. For the secondary, this should not be a hole. With a segments defined, it effectively clips the inner edge of the segments |
secondary mirror parameters |
1.0.0 |
1.5 cm, 0.416667 cm, 0.145816 cm, -0.712012 cm, 4.17685 cm, -23.1617 cm, 118.844 cm, -520.501 cm, 1802.98 cm, -4605.3 cm, 8019.1 cm, -8422.9 cm, 4004.61 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm |
Parameters for a polynomial defining the position of the secondary mirror along the optical axis and its shape. |
secondary mirror_ref radius |
1.0.0 |
558.63 cm |
The length scale to which the secondary_mirror_parameters apply. |
secondary mirror reflectivity |
1.0.0 |
Secondary mirror reflectivity measured directly on the facet as function of wavelength. |
|
secondary mirror segmentation |
1.0.0 |
Definition of segments or segment groups of the secondary reflector. |
|
secondary mirror shadow diameter |
1.0.0 |
-1.0 cm |
The diameter of any non-reflective but not transparent (black) central part of the secondary mirror in a dual- mirror telescope. |
secondary mirror shadow offset |
1.0.0 |
0.0 cm |
The offset of the shadowing element from the level of the edge of the secondary mirror. |
telescope axis height |
1.0.0 |
6.1 m |
Height of telescope elevation axis above ground level. |
telescope random angle |
1.0.0 |
0.0 deg |
Random (known) misalignment of the telescope in each axis (Gaussian r.m.s.). The resulting telescope pointing including this misalignment are saved as telescope azimuth and altitude pointing directions. |
telescope random error |
1.0.0 |
0.0 deg |
Random (unknown) alignment error of the telescope in each axis (Gaussian r.m.s.). The resulting telescope pointing including this misalignment is not saved to the simulation output. |
telescope sphere radius |
1.0.0 |
7.15 m |
Telescope fiducial sphere radius. |
telescope transmission |
1.0.0 |
0.971 , 1.0 , 0.158 , 5.376 , 1.069 , 0.0 |
Off-axis angle-dependent transmission, accounting for absorption and shadowing by masts. |
Camera#
Parameter Name |
Parameter Version |
Values |
Short Description |
|---|---|---|---|
adjust gain |
1.0.0 |
1.0 |
Gain adjustment for amplitudes and PMT gain. |
asum clipping |
1.0.0 |
0.0 mV |
The amplitude level at which the signal from each pixel (after optional shaping) is clipped for its contribution to the analog sum trigger. |
asum offset |
1.0.0 |
0.0 ns |
Offset in time where shaping convolution is done. |
asum threshold |
1.0.0 |
0.0 mV |
The amplitude level above which an analog sum leads to a telescope trigger. |
camera config file |
1.0.0 |
camera_CTA-SC-MST-54mmModPitch_0.5mmModDS_6.5mmPixAct_r1.dat |
Definition of pixel types, positions, status (on/off), relative gain (w.r.t the provided gain) and quantum/photodetector efficiency scaling (scale the provided quantum/photodetector efficiency distribution, ignoring wavelength dependence). |
camera degraded efficiency |
1.0.0 |
1.0 |
Camera efficiency degradation factor (wavelength independent). |
camera filter |
1.0.0 |
Wavelength dependence of the camera transmission, possibly as a function of incidence angle. |
|
camera pixels |
1.0.0 |
11328 |
Number of pixels in the camera. |
camera transmission |
1.0.0 |
1.0 |
Global wavelength-independent transmission factor of the camera, including any plexiglass window. |
channels per_chip |
1.0.0 |
4 |
Number of channels per readout chip. |
default trigger |
1.0.0 |
Majority |
Trigger algorithm used. |
disc_ac coupled |
1.0.0 |
1 |
Control AC coupling of the discriminators. |
disc_bins |
1.0.0 |
80 |
Number of time bins used for the discriminator simulation. |
disc_start |
1.0.0 |
0 |
Number of time bins by which the discriminator simulation is ahead of the FADC readout. |
discriminator amplitude |
1.0.0 |
1.0 mV |
Signal amplitude after amplifier per mean p.e. at the input of the discriminators/comparators. |
discriminator fall_time |
1.0.0 |
0.0 ns |
Fall time of the discriminator output after the logical output is reset to false. |
discriminator gate length |
1.0.0 |
-6.0 ns |
Effective discriminator gate length. |
discriminator hysteresis |
1.0.0 |
0.0 mV |
Value of the discriminator hysteresis. |
discriminator output amplitude |
1.0.0 |
1.0 mV |
The nominal output amplitude of a pixel discriminator as seen at the trigger group coincidence unit. |
discriminator output_var percent |
1.0.0 |
0.0 % |
Channel-to-channel variation (Gaussian r.m.s.) of the output amplitude of a pixel discriminator. |
discriminator pulse shape |
1.0.0 |
Pulse shape at the discriminator/comparator of an individual pixel. |
|
discriminator rise_time |
1.0.0 |
0.0 ns |
Rise time of the discriminator output. The output signal rises linearly within time frame. |
discriminator scale threshold |
1.0.0 |
1.0 |
Discriminator/comparator threshold scale factor. |
discriminator sigsum over threshold |
1.0.0 |
0.0 mV ns |
Integrated signal required over threshold. |
discriminator threshold |
1.0.0 |
7.45 mV |
Discriminator/comparator threshold. |
discriminator time_over threshold |
1.0.0 |
0.15 ns |
Time over threshold required before logic response switches to true. |
discriminator var_gate length |
1.0.0 |
0.07 ns |
Variation of gate length (Gaussian r.m.s). |
discriminator var_sigsum over threshold |
1.0.0 |
0.0 mV ns |
Gaussian r.m.s. spread of discriminator_sigsum_over_threshold (Pixel-to-pixel variation). |
discriminator var threshold |
1.0.0 |
0.0 mV |
Channel-to-channel variation of discriminator threshold. |
discriminator var_time over threshold |
1.0.0 |
0.0 ns |
Pixel-to-pixel variation of the time over threshold required before logic response switches to true. |
dsum clipping |
1.0.0 |
0 ct |
Amplitude level at which the digitized signal from each pixel is clipped. |
dsum ignore below |
1.0.0 |
0 ct |
FADC signal minimum contribution to digital signal sum. |
dsum offset |
1.0.0 |
0.0 ns |
Time offset applied before signal processing. |
dsum pedsub |
1.0.0 |
1 |
Expected pedestal is first subtracted before any shaping, scaling, clipping, etc. operations (if true). Without pedestal subtraction, shaping kernels with non-zero sum are not practical. |
dsum_pre clipping |
1.0.0 |
0 ct |
The amplitude level (in ADC counts above pedestal) at which the digitized signal from each pixel (before optional shaping) is clipped for its contribution to the digital sum trigger. A value of zero indicates no clipping is applied. Any such clipping is usually not a good idea, with FADC maximum value defined by fadc_max_signal anyway. |
dsum prescale |
1.0.0 |
0 , 0 |
Scaling of shaped signals. |
dsum presum_max |
1.0.0 |
0 |
Maximum of pre-sum in available number of bits. |
dsum presum shift |
1.0.0 |
0 |
After a patch-wise pre-summation, the resulting sum may be right-shifted to reduce the significant number of bits. |
dsum shaping renormalize |
1.0.0 |
0 |
The positive part of the shaping kernel is auto-normalized to a sum of 1.0 (if true). If false, the shaping kernel is used as-is. |
dsum threshold |
1.0.0 |
0.0 ct |
Amplitude level above which a digital sum leads to a telescope trigger. |
dsum_zero clip |
1.0.0 |
0 |
Clipping of negative shaped signals. |
fadc_ac coupled |
1.0.0 |
1 |
AC coupling of the FADCs. |
fadc amplitude |
1.0.0 |
7.63 ct |
Peak amplitude above pedestal for a photo electron with average signal. |
fadc_bins |
1.0.0 |
84 |
Number of FADC bins to be simulated. |
fadc compensate pedestal |
1.0.0 |
-1 |
Emulation of FADC pedestal compensation. |
fadc_dev pedestal |
1.0.0 |
0.0 |
Deviation of (F)ADCs pedestals in a single channel. (for high-gain channel in case of dual-readout chain). |
fadc_err compensate pedestal |
1.0.0 |
0.0 |
R.M.S. error on the pedestal evaluation for the compensation step. |
fadc_err pedestal |
1.0.0 |
0.08 ct |
Assumed error in initial calibration of pedestal (affects only the reported pedestal). |
fadc_lg amplitude |
1.0.0 |
1.0 ct |
Peak amplitude above pedestal for a photo electron with average signal (low-gain channels). |
fadc_lg compensate pedestal |
1.0.0 |
-1 |
Emulation of FADC pedestal compensation. |
fadc_lg dev pedestal |
1.0.0 |
-1.0 |
Deviation of (F)ADCs pedestals in a single channel (low-gain channels). |
fadc_lg err compensate pedestal |
1.0.0 |
-1.0 |
R.M.S. error on the pedestal evaluation for the compensation step. |
fadc_lg err pedestal |
1.0.0 |
-1.0 ct |
Assumed error in initial calibration of pedestal (low-gain channels; affects only the reported pedestal). |
fadc_lg max_signal |
1.0.0 |
-1 ct |
Maximum value of digitized signal per sample (low-gain channels). |
fadc_lg max_sum |
1.0.0 |
-1 ct |
The maximum value of a pulse sum produced by hardware pulse summation, in sum mode rather than recording pulse samples (low-gain channels). |
fadc_lg noise |
1.0.0 |
1.3 ct |
Gaussian r.m.s. spread of white noise per time bin in digitisation (low-gain channels). |
fadc_lg pedestal |
1.0.0 |
-1.0 ct |
(F)ADC pedestal value per time slice (low-gain channels). |
fadc_lg sensitivity |
1.0.0 |
-1.0 ct / mV |
FADC counts per mV voltage (for low-gain channels). |
fadc_lg sysvar pedestal |
1.0.0 |
-1.0 ct |
Systematic common variations of pedestals (low-gain channels). |
fadc_lg var pedestal |
1.0.0 |
-1.0 ct |
Channel-to-channel (or pixel-to-pixel) variation of the pedestal per FADC time slice (low-gain channels). Value is the r.m.s. of the randomly chosen pedestal values around the FADC pedestal. |
fadc_lg var sensitivity |
1.0.0 |
-1.0 |
Relative variations in sensitivity (even for FADCs of the same channel; low-gain channels). |
fadc_max signal |
1.0.0 |
65535 ct |
Maximum value of digitized signal per sample. |
fadc_max sum |
1.0.0 |
16777215 ct |
The maximum value of a pulse sum produced by hardware pulse summation, in sum mode rather than recording pulse samples. |
fadc_mhz |
1.0.0 |
1000.0 MHz |
FADC sampling rate. |
fadc_noise |
1.0.0 |
1.0 ct |
Gaussian r.m.s. spread of white noise per time bin in digitization. |
fadc pedestal |
1.0.0 |
1200.0 ct |
(F)ADC pedestal value per time slice (for high-gain channel for dual-gain readout). |
fadc_pulse shape |
1.0.0 |
(F)ADC pulse shape (amplitude vs time). |
|
fadc sensitivity |
1.0.0 |
1.0 ct / mV |
FADC counts per mV voltage. |
fadc_sum bins |
1.0.0 |
64 |
Number of bins read out in sampled data or summed up in ADC sum data. Corresponds to the experimental length of the readout window. |
fadc_sum offset |
1.0.0 |
37 |
Number of bins before telescope trigger where summing or reading of sampled data starts. |
fadc sysvar pedestal |
1.0.0 |
0.04 ct |
Systematic common variations of pedestals. |
fadc_var pedestal |
1.0.0 |
0.75 ct |
Channel-to-channel (or pixel-to-pixel) variation of the pedestal per FADC time slice. Value is the r.m.s. of the randomly chosen pedestal values around the FADC pedestal (for high-gain channel for dual-gain readout. |
fadc_var sensitivity |
1.0.0 |
0.02 |
Relative variations in sensitivity (even for FADCs of the same channel). |
flatfielding |
1.0.0 |
1 |
If enabled, the gains in pixels are adjusted to achieve the same signal from the same illumination. If disabled, the gains are adjusted to have equal single-p.e. amplitudes. |
gain variation |
1.0.0 |
0.02 |
Fractional gain variation between different photo detectors after adjusting the voltage to have approximately the same gain in all channels. |
hg_lg variation |
1.0.0 |
0.0 |
Relative pixel-to-pixel variation of the ratio of high-gain to low-gain amplitudes. |
multiplicity offset |
1.0.0 |
-0.5 |
Actual threshold of the telescope trigger, adjusted relative to the number of required pixels. |
muon_mono threshold |
1.0.0 |
0 , 0 |
Thresholds for mono muon events. |
nsb autoscale airmass |
1.0.0 |
0.83 , 0.2 |
NSB scaling as function of airmass (zenith angle). |
nsb_gain drop_scale |
1.0.0 |
0.0 GHz |
Pixel p.e. rate at which the gain drops to half the nominal value due to bias resistance and cell capacitance (SiPM cameras). |
nsb offaxis |
1.0.0 |
1.0 , 0.056 , 40.031 cm, 1.349 , 4.288 |
Fall-off of NSB with off-axis angle due to off-axis angle- dependent effective optical area. |
nsb_pixel rate |
1.0.0 |
all: 0.0321095 GHz |
Number of photo-electrons per nanosecond per pixel due to nightsky background. |
num_gains |
1.0.0 |
1 |
Number of different gains the input signal gets digitized. |
only triggered telescopes |
1.0.0 |
1 |
Switch to read out non-triggered telescopes. |
pedestal events |
1.0.0 |
0 |
Number of pedestal events at start of run with camera lid open (same NSB as for normal events). |
photon delay |
1.0.0 |
2.0 ns |
Additional delay added to the arrival times of all photons at the photo sensors. |
pixel cells |
1.0.0 |
14400 |
Modeling of pixel saturation. Value corresponds to the limited number of cells in a pixel (of SiPM type) which each can only fire once during the typical arrival time spread of Cherenkov photons. The presence of a non-zero value does not imply any microscopic model of the pixel structure. |
pixeltrg time_step |
1.0.0 |
0.0 ns |
Time difference between telescope and pixel trigger recording. |
pm_average gain |
1.0.0 |
40000.0 |
Photo detector average gain. Used to determine the DC currents from night-sky background (NSB) pixel rates. |
pm collection efficiency |
1.0.0 |
1.0 |
Photoelectron collection efficiency at the first stage of the photo detector. |
pm_gain index |
1.0.0 |
0.0 |
PMT gain g and voltage U are assumed to be related by the PMT gain index p through \(g \propto U^{p}\). Used only for PMT timing. |
pm photoelectron spectrum |
1.0.0 |
Single photoelectron (p.e.) response distribution (takes into account afterpulsing and the photoelectron collection efficiency for PMT cameras). |
|
pm_transit time |
1.0.0 |
1.0 ns, 0.0 ns, 0.0 V, 0.0 V |
Total transit time of the photodetector at the average voltage. |
pm_voltage variation |
1.0.0 |
0.0 |
Fractional high voltage variation, used to adjust the transit time variations (\(\propto 1/\sqrt(V)\)). |
qe variation |
1.0.0 |
0.03 |
Variation of quantum or photon detection efficiency (Gaussian r.m.s. spread of random fluctuations) between photo detectors in a given camera. Given in fraction of the average quantum or photon detection efficiency; the variation is applied independent of the wavelength. |
quantum efficiency |
1.0.0 |
Quantum or photon detection efficiency averaged over all pixels per camera. Random pixel-to-pixel variations are calculated using the qe_variation parameter. Pixel-to-pixel differences in detection efficiency using scaling factors can be specified in the camera_config_file. |
|
random mono probability |
1.0.0 |
0.0 |
Fraction of random mono events to pass stereo selection. |
teltrig min_sigsum |
1.0.0 |
0.0 mV ns |
Minimum signal sum at sector trigger over threshold. |
teltrig min_time |
1.0.0 |
1.5 ns |
Minimum time of sector trigger over threshold. |
transit time_calib error |
1.0.0 |
0.0 ns |
Accuracy with which the actual signal delay due to transit time variation and corresponding compensation can be determined. |
transit time compensate error |
1.0.0 |
0.0 ns |
Additional error (r.m.s.) in how well the number of steps for transit time compensation can be determined before the compensation is applied. |
transit time compensate step |
1.0.0 |
0.0 ns |
If signal delays can be compensated independent of the sampling, this is the time step in which this compensation can be done. A value of zero means no compensation is applied. The same compensation is applied to all channels. |
transit time_error |
1.0.0 |
0.0 ns |
Errors (r.m.s.) in transit time, not related to high voltage. |
transit time jitter |
1.0.0 |
0.15 ns |
Time jitter (Gaussian r.m.s. spread of random fluctuations) of individual photo-electrons. |
trigger current limit |
1.0.0 |
20.0 uA |
Pixels above this limit are excluded from the trigger. |
trigger delay compensation |
1.0.0 |
0.0 ns, 0.0 ns, 0.0 ns, 0.0 ns |
The delay applied to the trigger output to compensate for the different execution times of each trigger algorithm. |
trigger pixels |
1.0.0 |
3 |
Number of pixels required for single telescope trigger. |