MSTN-02#
The design model can be found here: MSTx-NectarCam.
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 |
1.0.0 |
-153.26 m, 169.01 m, 24.0 m |
Ground coordinate position of an array element. |
array element position utm |
1.0.0 |
217436.44 m, 3184918.08 m, 2173.0 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 |
291.8 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 |
0.0 cm |
Depth of the camera body (used to account for effects of shadowing). |
dish_shape length |
1.0.0 |
1920.0 cm |
Dish curvature length, best equal to focal length. |
effective focal length |
1.0.0 |
1644.51 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. |
focal length |
1.0.0 |
1600.0 cm |
Nominal overall focal length of the entire telescope. |
focus offset |
1.0.0 |
2.55 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 |
2.0 cm |
Gaussian r.m.s. spread of random fluctuations in the aligned mirror distance from the focus. |
mirror align random horizontal |
1.0.0 |
0.005 deg, 31.0 deg, 0.0135 , 0.012 |
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 |
0.005 deg, 31.0 deg, 0.0135 , 0.012 |
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 |
0 |
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 |
1607.0 cm |
Standard focal length of mirror tiles. |
mirror list |
1.0.0 |
List of mirror positions, diameters, focal lengths, and shape codes. |
|
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 |
0.006759 deg, 0.125 , 0.037 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 |
ray-tracing-North-MST-NectarCam-D-d10.0-za20.0_validate_optics.ecsv |
Derived properties of the telescope optics. |
parabolic dish |
1.0.0 |
False |
Parabolic dish shape is used. |
random focal length |
1.0.0 |
3.9 cm, 0.0 cm |
The spread of random fluctuations in mirror focal lengths. |
telescope axis height |
1.0.0 |
9.0 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 |
9.15 m |
Telescope fiducial sphere radius. |
telescope transmission |
1.0.0 |
0.908661 , 0.0 , 0.0 , 0.0 , 0.0 , 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 |
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 |
1855 |
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 |
93 |
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 |
6.8 mV |
Signal amplitude after amplifier per mean p.e. at the input of the discriminators/comparators. |
discriminator fall_time |
1.0.0 |
0.75 ns |
Fall time of the discriminator output after the logical output is reset to false. |
discriminator gate length |
1.0.0 |
-3.0 ns |
Effective discriminator gate length. |
discriminator hysteresis |
1.0.0 |
0.0 mV |
Value of the discriminator hysteresis. |
discriminator output amplitude |
1.0.0 |
525.0 mV |
The nominal output amplitude of a pixel discriminator as seen at the trigger group coincidence unit. |
discriminator output_var percent |
1.0.0 |
5.0 % |
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 |
0.8 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 |
29.0 mV |
Discriminator/comparator threshold. |
discriminator time_over threshold |
1.0.0 |
2.0 ns |
Time over threshold required before logic response switches to true. |
discriminator var_gate length |
1.0.0 |
0.0 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 |
2.0 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 |
1.0.0 |
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 |
True |
AC coupling of the FADCs. |
fadc amplitude |
1.0.0 |
19.56 ct |
Peak amplitude above pedestal for a photo electron with average signal. |
fadc_bins |
1.0.0 |
105 |
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 |
0.5 ct |
Assumed error in initial calibration of pedestal (affects only the reported pedestal). |
fadc_lg amplitude |
1.0.0 |
1.4 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 |
0.3 ct |
Assumed error in initial calibration of pedestal (low-gain channels; affects only the reported pedestal). |
fadc_lg max_signal |
1.0.0 |
4288 ct |
Maximum value of digitized signal per sample (low-gain channels). |
fadc_lg noise |
1.0.0 |
3.6 ct |
Gaussian r.m.s. spread of white noise per time bin in digitisation (low-gain channels). |
fadc_lg pedestal |
1.0.0 |
250.0 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 |
1.8 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 |
4095 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 |
3.6 ct |
Gaussian r.m.s. spread of white noise per time bin in digitization. |
fadc pedestal |
1.0.0 |
250.0 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 |
60 |
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 |
18 |
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 |
1.9 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 |
0.02 |
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. |
lightguide efficiency vs wavelength |
1.0.0 |
Lightguide efficiency for on-axis photons vs wavelength. |
|
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 |
0.84 , 0.29 |
NSB scaling as function of airmass (zenith angle). |
nsb offaxis |
1.0.0 |
0.0 , 0.0 , 0.0 cm, 0.0 , 0.0 |
Fall-off of NSB with off-axis angle due to off-axis angle- dependent effective optical area. |
nsb_pixel rate |
1.0.0 |
all: 0.207706 GHz |
Number of photo-electrons per nanosecond per pixel due to nightsky background. |
num_gains |
1.0.0 |
2 |
Number of different gains the input signal gets digitized. |
only triggered telescopes |
1.0.0 |
True |
Switch to read out non-triggered telescopes. |
photon delay |
1.0.0 |
27.0 ns |
Additional delay added to the arrival times of all photons at the photo sensors. |
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 |
4.0 |
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 |
20.0 ns, 9.7 ns, 300.0 V, 1100.0 V |
Total transit time of the photodetector at the average voltage. |
pm_voltage variation |
1.0.0 |
0.04 |
Fractional high voltage variation, used to adjust the transit time variations (\(\propto 1/\sqrt(V)\)). |
qe variation |
1.0.0 |
0.035 |
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 |
1.0 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 |
0.5 ns |
Errors (r.m.s.) in transit time, not related to high voltage. |
transit time jitter |
1.0.0 |
0.7 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. |