A Pass Plan contains one Segment Plan, which may be repeated. On the Pass Plan Form, each row in the segment plan contains one Observation Specification, which is used to create one or more Observations.

Pass Plan Parameters

The Pass Plan is constructed with a number of parameters described below and shown in the Figure of the Pass Plan View in APT. 

Number

APT Parameter Field NUMBER

An identification (ID) number that designates the Pass Plan. Required (incremental numbers are added by default but may be changed by the user). Non-number characters entered by the user are automatically replaced with the next available ID number. 

Label

APT Parameter Field LABEL

Enter a name that designates the Pass Plan. Not required. The label identifies the Pass Plan in the hierarchical editor and drop-down menus.

Pass Target

APT Parameter Field PASS TARGET = APT Value Field FIXED TARGET , APT Value Field REGION TARGET , APT Value Field MULTIPLE FIXED TARGETS , APT Value Field NONE

Select one or more targets for the pass plan. Options are:

APT Value Field FIXED TARGET Select one target from the list of Fixed Targets previously created for the program. All Observation Specifications defined in the Pass Plan use the selected Fixed Target.

APT Value Field MULTIPLE FIXED TARGETS When APT Value Field MULTIPLE FIXED TARGETS  is selected, one Fixed Target must be selected from APT Parameter Field OBSERVATION TARGET for each observation.

APT Value Field REGION TARGET Select one target from the list of Region Targets previously created for the program. All Observation Specifications defined in the Pass Plan use the selected Region Target. The entire Segment Plan will be executed at each location in the specified Region Target, including the entire sequence of specified Observations/Mosaics/Dither/Repeats.

APT Value Field NONE Available when an APT Restricted Field ENGINEERING special requirement is used.

Reference Position

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

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

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

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

Segment Plan (Observation Sequence) 

The Segment Plan 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 APT Parameter Field OBSERVATION REPEAT = 23 might be shown as 3 (25-47)).

Observation Target

APT Parameter Field OBSERVATION TARGET

Only available when  APT Parameter Field PASS TARGET = MULTIPLE FIXED TARGETS. Select a target for each observation from the list of Fixed Targets previously created for this program. For certain  APT Parameter Field CALIBRATION types,  APT Parameter Field OBSERVATION TARGET is set to APT Value Field NONE and cannot be changed. (For more information see Calibration).

Optical Element

  APT Parameter Field OPTICAL ELEMENT = APT Value Field F062 APT Value Field F087 APT Value Field F106 APT Value Field F129 APT Value Field F146 APT Value Field F158 APT Value Field F184 APT Value Field F213 APT Value Field Prism APT Value Field Grism

Select an Optical Element (the WFI Optical Elements are described in the Instrument Handbook). Prism and Grism are used for spectroscopic observations. The remaining Optical Elements are for imaging mode. For certain APT Parameter Field CALIBRATION types, APT Parameter Field Optical Element is set to  APT Value Field DARK and cannot be changed (For more information see Calibration).

Mosaic

APT Parameter Field MOSAIC

Select a Mosaic Pattern from those defined by the user for the program, or APT Value Field NONE .

  APT Value Field NONE is a single Tile representing a 1 by 1 pattern.

Dither

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

Select a Dither Pattern. The resulting dither pointings are shown in the Pointings Report. Available options are: NONE (default), LINEGAP2, LINEGAP3, LINEGAP4, BOXGAP4, WIDEGAP4, BOXGAP5, BOXGAP6, WIDEGAP6, BOXGAP7, BOXGAP8, WIDEGAP8, BOXGAP9, WIDEGAP9. For more information, see WFI Dithering.

Subpixel Dither

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

Select a subpixel dither. The subpixel dither pattern will be executed at each point in the Dither Pattern.  All resulting pointings are shown in the Pointings Report. Available options are: NONE (default), SUB2, SUB3, SUB4, SUB5, SUB6, SUB7, SUB8, SUB9. For more information, see WFI Dithering.

Exposures/Dither

APT Parameter Field EXPOSURES/DITHER

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

MA Table

  APT Parameter Field MA TABLE = APT Value Field HLWAS_IMAGING APT Value Field HLWAS_SPECTROSCOPY APT Value Field HLTDS_IMAGING1 APT Value Field HLTDS_IMAGING2 ` APT Value Field HLTDS_IMAGING3 ` APT Value Field HLTDS_IMAGING4 , APT Value Field HLTDS_SPECTROSCOPY , APT Value Field GBTDS

Select the Multi Accumulation Table (required) to be used for this Observation Specification.

Resultant

APT Parameter Field RESULTANT

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. Each MA Table has a recommended minimum number of resultants. If the selected number is less than the recommended minimum, APT provides a warning.

Repeat

APT Parameter Field OBSERVATION REPEAT

Enter the number of repeats for this Observation Specification (not required).  The allowed range is APT Range Field 1-100 and each Observation is assigned an observation number (see Row Number). A APT Parameter Field Repeat of 1 is only 1 total execution of the observation.

Number of Visits

Tally of the number of visits for this Observation Specification. The sum is automatically calculated and is not editable.

Special Reqs

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

Repeat

APT Parameter Field SEGMENT REPEAT

Enter the number of times the Segment Plan is repeated (not required). This option is not available if the APT Parameter Field PASS TARGET is a Region Target. The allowed range is APT Range Field 1-250 . A  APT Parameter Field Repeat of 1 is only 1 total execution of the Segment.

Total Visits

Tally of the total number of visits in the Segment Plan. Automatically generated.

Special Requirements

The Special Requirements tab displays all Special Requirements for the selected pass plan. Special requirements 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 at STScI.