==== Science IFU template METIS_ifu_ext_obs_FixedSkyOffset ====

=== Procedure for METIS_ifu_ext_obs_FixedSkyOffset ===
 
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Setup IFU|
  * User can choose the central wavelength (INS WLEN CEN) from a pre-defined list. The system then sets the order, and the grating tilt of the Echelle necessary to provide the required setting.
    * ''LMS PP4'' Select pre-dispersed range (order)
    * ''LMS PP5'' Select main dispersed range 
  * Set detector parameters (DIT, NDIT, readout mode, cube mode T/F)
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Start science exposures|
  * This template moves the telescope or the chopper alternatively between OBJECT and SKY positions, in the same way it does in imaging.
  * The OBJECT positions are randomly distributed around the initial telescope position and within a box defined by the parameter ''Jitter Box Width'' (in arcsec). In the extended mode, the offsets are performed only in the along-slice direction, keeping the target always in the middle of the three used slices.
  * The SKY positions are randomly distributed around a position set at a constant distance from the initial telescope pointing. This distance is defined by the parameters ''Sky offset in RA'' and ''Sky offset in DEC''. The dither around this position is calculated to be within a ''Jitter Box Width''.
  * Offsets to sky an dithering are performed using CFO-PP2 chopper or telescope offsets (TBD).
  * The observing sequence is performed as OSO-OSO, where O,S refer to OBJECT,SKY exposures. The keyword NOSOCycles defines the number of OSO cycles.
  * There are gaps in the instantaneous wavelength coverage of the LMS, which can be accounted for by tilting slightly the main dispersion grating. The user can select the angle of the dispersion grating from a list of pre-defined named positions, or can explicitly specify the desired angle (TBD).
  * The science sequence is repeated at each setting of the main dispersion grating angle. 
  * At each offset position start science exposures with DIT/NDIT. 
  * Read-out and save individual exposures, or co-added frames, depending on the ''cube mode'' T/F keyword.
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End science exposures|
  * Return telescope or chopper (depending on which actuator is used for offsetting) back to the initial position.
  * Collect headers
  * Merge into one or more data cubes
  * Send cube to ESO Archive
  * Send cube to Pipeline machine or ICS storage (tbd)
  * Go back to //Setup IFU// until target observations are finished (single OB). For example, to observe at a different central wavelength.

At the end of the OB:
  * Stop chopper
  * Stop CFO pupil stabilization
  * Stop AO
    * open loop
    * stop field stabilization
    * stop registration
    * stop modulation
  * Stop derotator
  * Handover to telescope
    * CCS takes control of M4 and M5
    * Telescope gets ready for next preset
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===Parameters for METIS_ifu_ext_obs_FixedSkyOffset===

^Parameter             ^Hidden     ^Range (default)            ^Label^  
|DPR CATG              |yes        |SCIENCE TEST (SCIENCE)     |Data product category|
|DPR TECH              |yes        |IFU (IFU)                  |Data product technique|
|DPR TYPE              |yes        |OBJECT SKY (OBJECT)        |Data product type|                            
|DET1 DIT               |yes         |0..TBD (NODEFAULT)         |IMG-LM Detector integration time (DIT)|
|DET1 NCORRS NAME       |no         |TBD                         |IMG-LM Readout mode|
|DET3 DIT               |yes         |0..TBD (NODEFAULT)         |LMS Detector integration time (DIT)|
|DET3 NCORRS NAME       |no         |TBD                         |LMS Readout mode|
|DET1 CUBE MODE        |yes         |T F (T)                    |Toggle cube mode| 
|DET3 CUBE MODE        |yes         |T F (T)                    |Toggle cube mode| 
|SEQ JITTER WIDTH      |no         |0..5 (NODEFAULT)           |Jitter Box Width (arcsec)|
|SEQ NOSOCYCLES         |no         |0..100 (NODEFAULT)         |Number of OSO cycles|
|SEQ TIME OBJECT       |no         |0..TBD (NODEFAULT)         |Total integration time on OBJECT position (sec)|
|SEQ TIME SKY          |no         |0..TBD (NODEFAULT)         |Total integration time on SKY position (sec)|
|SEQ DET1 NDIT OBJECT       |yes         |1..1000 (NODEFAULT)       |NDIT on OBJECT positions IMG-LM|
|SEQ DET1 NDIT SKY          |yes         |1..1000 (NODEFAULT)       |NDIT on SKY positions IMG-LM|
|SEQ DET3 NDIT OBJECT       |yes         |1..1000 (NODEFAULT)       |NDIT on OBJECT positions LMS|
|SEQ DET3 NDIT SKY          |yes         |1..1000 (NODEFAULT)       |NDIT on SKY positions LMS|
|SEQ NEXPO             |no         |0..1000 (NODEFAULT)        |Number of exposures per offset|
|SEQ OBSTYPE LIST      |no         |O S (NODEFAULT)            |Observation type list, O/S|
|SEQ OFFSET COORDS     |no         |SKY DETECTOR (DETECTOR)    |Offset coordinate type selection|
|SEQ SKYOFFSET ALPHA   |no         |0..TBD (10)                |RA offset to sky|
|SEQ SKYOFFSET DELTA   |no         |0..TBD (10)                |DEC offset to sky|
|SEQ POISSON           |yes        |1..100 (10)                |Random throw generator
|SEQ RETURN            |no         |T F (T)                    |Return to origin?|
|SEQ CFO CHOP POSANG       |yes        |0..360 (NODEFAULT)         |Chopper position angle|
|SEQ CFO CHOP THROW        |yes        |0..5 (NODEFAULT)           |Chop throw|
|SEQ CFO CHOP FREQ         |yes        |TBD                        |Chopping frequency|
|INS WLEN CEN         |no         |2700 - 5300 nm (NODEFAULT)           |Central wavelength|
|INS OPTI10 NAME         |no         |L' H2Oice shortL IB4.05 PAH3.3 PAH3.3ref Br-alpha Br-alpharef M' CO(1-0)/ice COref HCIL-short HCIL-long (L')                |IMG-LM Filter name|
|INS OPTI11 NAME         |no         |OPEN ND1 ND2 ND3 ND4 ND5 (NODEFAULT)                  |IMG-LM Neutral density filter|