SSTS-21#
The design model can be found here: SSTS-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 |
-504.03 m, -494.45 m, 59.25 m |
Ground coordinate position of an array element. |
array_element_position_utm |
2.0.0 |
367321.0 m, 7268967.0 m, 2203.0 m |
UTM coordinate position of an array element. |
axes_offsets |
1.0.0 |
70.0 cm, 70.0 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 |
49.5 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 |
2 |
Camera body shape parameter (used to account for effects of shadowing). |
camera_depth |
1.0.0 |
50.164 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 |
215.191 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 |
215.0 cm |
Nominal overall focal length of the entire telescope. |
focal_surface_parameters |
1.0.0 |
258.88 cm, -0.00471698 cm, -1.04952e-07 cm, -4.67036e-12 cm, -2.59788e-16 cm, -1.61847e-20 cm, -1.08033e-24 cm, -7.55454e-29 cm, -5.46285e-33 cm, -4.0516e-37 cm, -3.06502e-41 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 |
1.0 cm |
The length scale to which the focal_surface_parameters apply. |
focus_offset |
1.0.0 |
0.0 cm, 0.0 deg, 0.0 , 0.0 |
Distance of the starlight focus from the camera pixels (light guides) entry. |
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_offset |
1.0.0 |
0.0 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 |
0.0255 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. |
|
optics_properties |
1.0.0 |
Derived properties of the telescope optics. |
|
parabolic_dish |
1.0.0 |
False |
Parabolic dish shape is used. |
pixels_parallel |
1.0.0 |
2 |
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 |
424.1 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 |
0.0 cm |
The diameter of any non-reflective part of the primary mirror. |
primary_mirror_incidence_angle |
1.0.0 |
Distribution of incidence angle on the SST primary mirror. |
|
primary_mirror_parameters |
1.0.0 |
0.0 cm, 0.000608051 cm, -7.36248e-10 cm, 5.82125e-15 cm, -6.76447e-20 cm, -3.89542e-24 cm, -5.28036e-29 cm, 2.99107e-34 cm, 4.39153e-38 cm, 6.17433e-43 cm, -2.73586e-47 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 |
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 |
1.0 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. |
|
secondary_mirror_baffle |
2.0.0 |
298.1 cm, 276.9 cm, 97.0 cm, 10.0 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 |
180.0 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 |
0.0 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_incidence_angle |
1.0.0 |
Distribution of incidence angle on the SST secondary mirror. |
|
secondary_mirror_parameters |
1.0.0 |
310.84 cm, 0.00229358 cm, 2.8273e-08 cm, -2.7689e-12 cm, 8.80066e-17 cm, 3.37315e-21 cm, -1.02973e-25 cm, -6.72882e-30 cm, -3.06437e-34 cm, 3.1718e-38 cm, -3.71217e-43 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 |
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 |
1.0 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_shadow_diameter |
2.0.0 |
214.0 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 |
2.0.0 |
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 |
3.25 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 |
3.0 m |
Telescope fiducial sphere radius. |
telescope_transmission |
2.0.0 |
0.921 , 1.0 , 14.924 , 310.479 , 1.21 , 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 |
2.0.0 |
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 |
2.0.0 |
Wavelength dependence of the camera transmission, possibly as a function of incidence angle. |
|
camera_pixels |
1.0.0 |
2048 |
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 |
128 |
Number of time bins used for the discriminator simulation. |
disc_start |
1.0.0 |
3 |
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 |
-8.0 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 |
2.0.0 |
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 |
3.0.0 |
10.93 mV |
Discriminator/comparator threshold. |
discriminator_time_over_threshold |
2.0.0 |
0.15 ns |
Time over threshold required before logic response switches to true. |
discriminator_var_gate_length |
2.0.0 |
0.075 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 |
0.25 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 |
2.0.0 |
True |
AC coupling of the FADCs. |
fadc_amplitude |
2.0.0 |
6.74 ct |
Peak amplitude above pedestal for a photo electron with average signal. |
fadc_bins |
1.0.0 |
160 |
Number of FADC bins to be simulated. |
fadc_compensate_pedestal |
1.0.0 |
-1 |
Emulation of FADC pedestal compensation. |
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 |
0.0 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_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_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 |
2.0.0 |
4.7 ct |
Gaussian r.m.s. spread of white noise per time bin in digitization. |
fadc_pedestal |
2.0.0 |
1000.0 ct |
(F)ADC pedestal value per time slice (for high-gain channel for dual-gain readout). |
fadc_pulse_shape |
2.0.0 |
(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 |
128 |
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 |
24 |
Number of bins before telescope trigger where summing or reading of sampled data starts. |
fadc_sysvar_pedestal |
1.0.0 |
0.0 ct |
Systematic common variations of pedestals. |
fadc_var_pedestal |
2.0.0 |
1.0 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 |
0.0 |
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 |
0.05 |
Fractional gain variation between different photo detectors after adjusting the voltage to have approximately the same gain in all channels. |
lightguide_efficiency_vs_incidence_angle |
1.0.0 |
Lightguide efficiency as a function of incidence angle. |
|
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 |
2.0.0 |
0.84 , 0.29 |
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 |
2.0.0 |
1.0 , 0.154 , 14.19 cm, 2.133 , 0.993 |
Fall-off of NSB with off-axis angle due to off-axis angle- dependent effective optical area. |
nsb_pixel_rate |
3.0.0 |
all: 0.13212 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 |
5.0 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_photoelectron_spectrum |
2.0.0 |
Single photoelectron (p.e.) response distribution (takes into account afterpulsing and the photoelectron collection efficiency for PMT cameras). |
|
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 |
2.0.0 |
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 |
2.0.0 |
0.01 |
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 |
0.5 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 |
2.0.0 |
0.3 ns |
Errors (r.m.s.) in transit time, not related to high voltage. |
transit_time_jitter |
2.0.0 |
0.1 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 |
2 |
Number of pixels required for single telescope trigger. |