IMaX: Calibrations and Observations

The software's point of view

Calibrations and Observations

● Exposure Time● Focus● Wavelenghts● Phase diversity● Flat field● Dark current

● Standard Observing Modes (OM)

– VS, VM– LS, LM– DM

● New OM– V3, V5, V6, V7,

V12– L3, L5, L6, L7,

L12

Calibrating: Exposure Time

● It acquires six images with increasing exposure time.

● It calculates the average for every image (centered square 500x500) and ignores the ones with an average over 85% of the max value for a pixel.

● It adjusts a line with the rest of the points and takes the value corresponding to 2500 counts.

Calibrating: Exposure Time● Use of “CalibrateExposureTime” DECO.● This DECO takes six different times (in

milliseconds) as parameters.● It sets the Etalon voltage to the 5th of the VS OM.● It needs the dark current image.● It calibrates both cameras.● It updates CF (HD & Mem).

ImageAcquisition.Camera_1_ExposureTime & ImageAcquisition.Camera_2_ExposureTime

Calibrating: Focus

● It takes a single image and calculates RMS for a centered square (500x500).

● RMS:

RMS= standard deviationaverage

Calibrating: Focus

● Use of TC “CalculateContrast”. Long duration & low priority.

● Process coordinated by the ICU.● It just uses camera 1.● It needs dark current and flat field image.● It sets the Etalon voltage to the 5th of the VS

OM.● It sends a HK with the calculated contrast.

Calibrating: Wavelengths

● It takes images with increasing wavelength values.

● It calculates an average for every image in a centered square(50x50). It takes the minimum average and two from every side. It adjusts a parabola for these five points. The minimum of the parabola allows us to obtain the offset of the line ('a').

λ=a+bV● This way we can obtain the new voltages for

the Observing Modes.

Calibrating: Wavelengths

● Use of CalibrateWavelengths DECO.● It takes v0, v1 and vdelta as parameters.● It needs flat field and dark current images.● It just uses camera 1.● It calculates the new 'a' coefficient and writes

it to the CF (HD & Mem).● It recalculates the new CF voltages to all the

OM with the new 'a' coefficient and writes it to the CF (HD & Mem).

Calibrating: File names

● The images used for calibration are stored in the ICU DSS.

● cal_exp_cam_x_n_y.raw, where x is the camera and y is the exposure time argument number.

● cal_focus_cam_1_n_x.raw, where x is an increasing counter of the focus calibration carried out.

● cal_lambda_v_x.raw, where x is the voltage in counts.

Calibrating: Phase Diversity

● It sets the Etalon voltage to the 5th of the VS OM.● It sets ROCLIs to p1 of the VS OM.● Accumulation?● Truncation bits: 0● No demodulation● It sets the PD at the beginning and unset at the

end.

Calibrating: Dark current & flat field

● Provided by the scientist team as raw images during AIV in Esrange.

Former Observing Modes

● The former observing modes takes the the following parameters from the CF.

● Grouped by OM (VS, VM, LS, LM & DM):– Iddle time– Discarded frames– Accumulations– Truncation bits– Demodulate– Etalon voltages– ROCLI voltages

Former Observing Modes

● Grouped by tuning mode (FPTM, ITM, DMM) and Camera

– Demodulation matrix● All of them have only one:

– Camera 1 exposure time– Camera 2 exposure time– Max observing time– Max number of cycles– Max time to enter science mode– Lambda to voltage function coefficients

New Observing Modes● All of them use the Configurable mode for (including

V3, V5, L3 and L5):– Iddle time– Discarded frames– Accumulations– Truncation bits– Demodulate– Etalon voltages– ROCLI voltages

New Observing Modes

● V3, V5, V6, V7and V12 use FPTM demodulation matrix

● L3, L5, L6, L7 and L12 use ITM demodulation matrix

● All of them have only one (same as former):– Camera 1 and camera 2 exposure time– Max observing time– Max number of cycles– Max time to enter science mode– Lambda to voltage function coefficients

New Observing Modes

● Due to timing restrictions, all of them use FPTM tuning mode.

● Wavelengths are fixed and translated to voltages at the beginning of the execution with the 'a' and 'b' coefficients from the CF.

● For the V# OM, the ROCLI retardances(number of retardances and values) and truncation bits are copied from the Vector Spectropolarimeter OM values. The demodulation matrix applied are the ones for the FPTM.

New Observing Modes

● For the L# OM, the ROCLI retardances(number of retardances and values) and truncation bits are copied from the Longitudinal Spectropolarimeter OM values. The demodulation matrix applied are the ones for the ITM.

New Observing Modes: Simulating ITM with FPTM

● Because L3, L5, L6, L7 and L12 are carried out with a FPTM, some tricks have to be applied:

– Because FPTM needs 4 polarizations for the ROCLIs, the 2 polarizations are performed twice.

– The 4x4 demodulation matrix is built from the 2x2:

a bc d ⇒a b 0 0

c d 0 00 0 a b0 0 c d

Observing DECOs

● SetObservingMode(dswMode, camera, ccdTimeExposure, iddleTime, accumulations, truncation, demodulation, wavelengthsNo, RocliNo, wavelengths[5], retardancesR1[4], retardancesR2[4], discards[5], cycles, time)

● StartVectorSpectropolarimeterOM(cycles, time), same for StartVectorMagnetographOM, StartLongitudinalSpectropolarimeterOM, StartLongitudinalMagnetographOM and StartDeepMagnetographOM.

Observing DECOs

● StartConfigurableOM(cycles, time, tuningMode)

● StartV3ObservingMode(accumulations, cycles, time, demodulation), same for StartV5ObservingMode, StartV6ObservingMode, StartV7ObservingMode, StartV12ObservingMode, StartL3ObservingMode StartL5ObservingMode, StartL6ObservingMode, StartL7ObservingMode and StartL12ObservingMode.

Observing DECOs● ChangeCF_LambdaToVoltageCoefficient_A(a,

writeToCFHD)● ChangeCF_LambdaToVoltageCoefficient_B(a,

writeToCFHD)