SCTS-117#
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 |
311.59 m, -165.08 m, 27.5 m |
Ground coordinate position of an array element. |
array_element_position_utm |
2.0.0 |
366984.0 m, 7269779.0 m, 2165.5 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. |
|
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 |
False |
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 |
True |
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 |
True |
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 |
False |
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 |
1.0.1 |
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 |
True |
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 |
True |
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 |
True |
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. |