A Pass Plan contains one Observation Sequence, which contains specifications for one or more observations. Each observation may optionally be Repeated within the observation sequence. The entire observation sequence itself may be executed multiple times using Segments Per Pass. Pass Plans are executed only as part of a Survey Plan.

Pass Plan Parameters

A Pass Plan contains one or more observation specifications as shown in the Figure of the Pass Plan View in APT. Parameters may be entered or edited on the Pass Plan form. 

Number

NUMBER

An identification (ID) number that designates the Pass Plan. Required (incremental numbers are added by default but may be changed by the user).

 Label

LABEL Enter a name that designates the Pass Plan (optional). The label identifies the Pass Plan in the hierarchical editor and drop-down menus.

Pass Target

PASS TARGET = Fixed Target , Region Target , MULTIPLE FIXED TARGETS , NONE , PARALLEL

Select the target to be used for all observations. Options are:

Fixed Target Select a target from the list of Fixed Targets previously created for the program. 

Region Target Select a target from the list of Region Targets previously created for the program. The entire Observation Sequence will be executed at each location in the specified Region Target, including the entire sequence of specified Observations/Mosaics/Dither/Repeats.

NONE Available when an ENGINEERING special requirement is used.

PARALLEL (see Parallel CGI/WFI Programs).

MULTIPLE FIXED TARGETS  Select this option when including both internal and external targets in a Pass Plan. When Multiple Fixed Targets is selected,  an Observation Target must be specified for each observation.

Reference Position

All targets in the Survey Plan are observed at the same orient with respect to the  Reference Position . Reference Position  is optional and may be entered manually or automatically.

To add the Reference Position automatically, click the Set Reference Position button. APT calculates the Reference Position  RA/Dec as the center of all coordinates in the Survey Plan.  

Right ascension ( RA ) and declination ( Dec )  must be entered as ICRS coordinates (International Celestial Reference System).

• RA may be entered in HMS format (hh mm ss.ssss), or as decimal degrees (ddd.dddd). Decimal numbers will be converted to HMS. 
• Dec may be entered in DMS format (dd mm ss.ssss) or as decimal degrees (ddd.dddd). Decimal degrees will be converted to DMS.

Observation Sequence 

The Observation Sequence is an ordered list of one or more Observation Specifications. Each Observation Specification associates a target with a Mosaic Pattern, an instrument set up, and a Dither Pattern.

Row Number

A sequential number for the Observation Specification (assigned by APT). When Observation Repeat is used, the Row Number expands to also show the range of assigned observation numbers. 

Example: The third row with OBSERVATION REPEAT = 23 might be shown as 3 (25-47)).

Observation Target

OBSERVATION TARGET

Only available when  PASS TARGET = MULTIPLE FIXED TARGETS. Select a target for each observation from the list of Fixed Targets previously created for this program.   Only one fixed target may be used in an observation sequence.

For certain  CALIBRATION types,  OBSERVATION TARGET is set to NONE and cannot be changed. For more information see Calibration Requirements. 

Optical Element

  OPTICAL ELEMENT = F062 F087 F106 F129 F146 F158 F184 F213 Prism Grism

Select an Optical Element (WFI Optical Elements are described in the Instrument Handbook).

• Prism and Grism are used for spectroscopic observations.
• For certain  CALIBRATION types, Optical Element is set to  DARK and cannot be changed (For more information see Calibration Requirements).
• All other Optical Elements are used for imaging mode.

MA Table

Select the Multi Accumulation Table (required) to be used for this Observation Specification. Available MA Tables depend on the selected Optical Element and whether Restricted Access is allowed.

The name of each MA Table indicates its intended use. All MA Tables are listed below.

• The prefix of the MA Table name indicates whether it used for either Imaging or Spectroscopic observations: 
  • Imaging Mode - MA Table names begin with "IM_"
  • Spectroscopy - MA Table names begin with "SP_"
• The middle number is the approximate maximum exposure time in seconds. 
• The final number is the number of resultants in the MA Table. 
• Tables with the _S suffix are for sparse fields only. Do not use in dense fields (e.g. the galactic plane).
• After the MA Table name, the drop-down list shows the exposure time for the maximum allowed resultants for the MA Table.

For example, the table name IM_107_7 corresponds to a science Imaging mode table with an approximate maximum exposure time of 107 seconds with a total number of 7 resultants.  

Please see WFI MultiAccum Tables for more information about the available Roman MA Tables. All MA Tables are listed below for convenience.

Resultant

RESULTANT

(available only when Allow Restricted is selected)

Select the resultant at which to stop observing for the selected MA Table (see Multi Accumulation Table). Each MA Table has a defined number of resultants, and the observation is truncated at the selected resultant number.

• The drop-down list displays the Total Integration Duration (in seconds) for each resultant option (see Multi Accumulation Table).
• If the selected number of resultants is less than the recommended minimum for the selected MA Table, APT provides a warning.
• When Allow Restricted is not selected, RESULTANT is not shown but the Resultant value is the highest resultant for the selected MA Table.

Mosaic

MOSAIC

Select a Mosaic Pattern from those already defined  in the program, or NONE .

  NONE is a single Tile representing a 1 by 1 pattern.

Dither

  DITHER = NONE (default), LINEGAP2 LINEGAP3 LINEGAP4 BOXGAP4 WIDEGAP4 BOXGAP5 BOXGAP6 WIDEGAP6 BOXGAP7 BOXGAP8 WIDEGAP8 BOXGAP9 WIDEGAP9

Select a Dither Pattern.  For more information, see WFI Dithering.

Subpixel Dither

SUBPIXEL DITHER = NONE (default), SUB2 SUB3 SUB4 SUB5 SUB6 SUB7 SUB8 SUB9

Select a subpixel dither. The subpixel dither pattern will be executed at each point in the Dither Pattern.  For more information, see WFI Dithering.

Exposures/Dither

EXPOSURES/DITHER

Enter the number of exposures to be executed at each of the dither and subpixel dither points. (Optional) The range is 1-99

Repeat

OBSERVATION REPEAT

Enter the number of observations to create using this Observation Specification (optional). The allowed range is 1-100 and each Observation is assigned an observation number (see Row Number). A Repeat of 1 is only 1 total execution of the observation (and a repeat of 2 is 2 total observations). 

Visits

VISITS

The calculated total number of Visits for this Observation Specification. The sum is automatically calculated and is not editable.

Special Reqs

Indicates how many Requirements have been applied to the Observation Specification. The details of the user-defined Requirements for the selected  Observation Specification are listed in the Special Requirements tab. 

Observations Per Segment

OBSERVATIONS PER SEGMENT

The calculated number of observations in each segment. Not editable.

Visits Per Segment

VISITS PER SEGMENT

The calculated number of Visits in each segment. Not editable.

Visits Per Pass

VISITS PER PASS

The calculated number of Visits in each pass. Not editable.

Segments Per Pass

SEGMENTS PER PASS

Enter the number of times the Observation Sequence is executed (optional). The allowed range is 1-250 . A  SEGMENTS PER PASS of 1 is only 1 total execution of the Segment.

For Region Targets,  SEGMENTS PER PASS is set to the number of pointings for the Region Target and cannot be changed.

Science Time (sec) 

SCIENCE TIME

Total exposure time in seconds required to complete the entire Pass Plan, excluding required overhead time. Not editable.

Execution Time (sec)

EXECUTION TIME

Total time in seconds required to complete the entire Pass Plan, excluding statistical external overheads such as certain slews. Not editable.

Data Volume (MB)

DATA VOLUME

Total data volume in megabytes calculated for the entire Pass Plan. Not editable.

Special Requirements

The Special Requirements tab displays all Requirements for the selected Observation Specification. Special requirements are optional and may be added, removed, or edited here. 

Comments

The Comments tab displays comments entered for the Pass Plan. Comments may be added, removed, or edited here. Comments are not required.

For additional questions not answered in this article, please contact the Roman Help Desk.