Engineering MultiAccum Tables
This article describes each of the Roman Wide Field Instrument (WFI) engineering MultiAccum (MA) tables. These tables are restricted for nearly all users.
The multi-accumulation tables (also called MultiAccum or MA Tables) define the sequence of detector reads that are taken during a WFI exposure. Additional details about these tables can be found in WFI MultiAccum Tables article. For guidance on how the choice of MultiAccum Table influences sensitivity, saturation, and exposure-time trade-offs in Roman WFI observations, see Understanding Roman WFI Sensitivity, Saturation, and Exposure Time.
The MA tables below are specific to the WFI imaging mode. For each table, the following is provided:
- a general summary table, and
- a table listing the properties of each resultant.
The MA tables for the imaging mode can be found in the Imaging MultiAccum Tables article. The MA tables for the spectroscopic mode can be found in the Spectroscopy MultiAccum Tables article.
The MA tables described below correspond to "Rev H".
Table of Engineering MA Tables
These tables are restricted and used for engineering or calibration purposes. A majority of users will not be able to use the tables listed below.
| MA Table Name | MA Table Number | Number of Resultants | Maximum Exposure Time (seconds) | Additional Notes |
|---|---|---|---|---|
| DROP_10_OF_11 | 9005 | 47 | 1600 | Restricted Mode |
| DROP_4_OF_5 | 9006 | 102 | 1600 | Restricted Mode |
| DROP_3_OF_4 | 9007 | 128 | 1610 | Restricted Mode |
| DROP_2_OF_3 | 9008 | 170 | 1605 | Restricted Mode |
| DROP_1_OF_2 | 9009 | 255 | 1610 | Restricted Mode |
| IM_DIAGNOSTIC | 9010 | 300 | 950 | Restricted Mode |
| SP_DIAGNOSTIC | 9011 | 300 | 1550 | Restricted Mode |
| DEFOCUS_MED_V2 | 9012 | 15 | 410 | Restricted Mode |
| DEFOCUS_LRG_V2 | 9013 | 15 | 595 | Restricted Mode |
DROP_10_OF_11 Restricted Mode
This mode is intended to be used for engineering purposes and is not anticipated to be used for science observations.
Note that each engineering MA table is executed from the beginning of the sequence but may be truncated at any arbitrary resultant before reaching the end of the table. MA table truncation may result in undesirable effects in the data. The recommended minimum number of resultants for each MA table is indicated below. Users are also advised to choose a final resultant that contains a single read for optimal cosmic-ray rejection during data processing.
Table of DROP_10_OF_11 (General Properties)
| MA Table Name | DROP_10_OF_11 |
| Maximum Resultants | 47 |
| Minimum Recommended Resultants | 1 |
| WFI Observing Mode | WIM |
| Science Read Time | 3.16247 |
| Number of Reset Reads | 1 |
| Reset Read Time | 3.16248 |
| Subtract Reference Read | True |
| MA Table Number | 9005 |
| MA Table ID | SCI9005 |
MA Table Description | Engineering mode; downlinks every 11th read; maximum integration ~1600 seconds |
Changes to the technical details and other specifications presented here are expected as a part of commissioning and early operations.
Table of DROP_10_OF_11 (Resultants)
DROP_4_OF_5 Restricted Mode
This mode is intended to be used for engineering purposes and is not anticipated to be used for science observations.
Note that each engineering MA table is executed from the beginning of the sequence but may be truncated at any arbitrary resultant before reaching the end of the table. MA table truncation may result in undesirable effects in the data. The recommended minimum number of resultants for each MA table is indicated below. Users are also advised to choose a final resultant that contains a single read for optimal cosmic-ray rejection during data processing.
Table of DROP_4_OF_5 (General Properties)
| MA Table Name | DROP_4_OF_5 |
| Maximum Resultants | 102 |
| Minimum Recommended Resultants | 1 |
| WFI Observing Mode | WIM |
| Science Read Time | 3.16247 |
| Number of Reset Reads | 1 |
| Reset Read Time | 3.16248 |
| Subtract Reference Read | True |
| MA Table Number | 9006 |
| MA Table ID | SCI9006 |
MA Table Description | Engineering mode; downlinks every 5th read; maximum integration ~1600 seconds |
Changes to the technical details and other specifications presented here are expected as a part of commissioning and early operations.
Table of DROP_4_OF_5 (Resultants)
DROP_3_OF_4 Restricted Mode
This mode is intended to be used for engineering purposes and is not anticipated to be used for science observations.
Note that each engineering MA table is executed from the beginning of the sequence but may be truncated at any arbitrary resultant before reaching the end of the table. MA table truncation may result in undesirable effects in the data. The recommended minimum number of resultants for each MA table is indicated below. Users are also advised to choose a final resultant that contains a single read for optimal cosmic-ray rejection during data processing.
Table of DROP_3_OF_4 (General Properties)
| MA Table Name | DROP_3_OF_4 |
| Maximum Resultants | 128 |
| Minimum Recommended Resultants | 1 |
| WFI Observing Mode | WIM |
| Science Read Time | 3.16247 |
| Number of Reset Reads | 1 |
| Reset Read Time | 3.16248 |
| Subtract Reference Read | True |
| MA Table Number | 9007 |
| MA Table ID | SCI9007 |
MA Table Description | Engineering mode; downlinks every 4th read; maximum integration ~1610 seconds |
Changes to the technical details and other specifications presented here are expected as a part of commissioning and early operations.
Table of DROP_3_OF_4 (Resultants)
DROP_2_OF_3 Restricted Mode
This mode is intended to be used for engineering purposes and is not anticipated to be used for science observations.
Note that each engineering MA table is executed from the beginning of the sequence but may be truncated at any arbitrary resultant before reaching the end of the table. MA table truncation may result in undesirable effects in the data. The recommended minimum number of resultants for each MA table is indicated below. Users are also advised to choose a final resultant that contains a single read for optimal cosmic-ray rejection during data processing.
Table of DROP_2_OF_3 (General Properties)
| MA Table Name | DROP_2_OF_3 |
|---|---|
| Maximum Resultants | 170 |
| Minimum Recommended Resultants | 1 |
| WFI Observing Mode | WIM |
| Science Read Time | 3.16247 |
| Number of Reset Reads | 1 |
| Reset Read Time | 3.16248 |
| Subtract Reference Read | True |
| MA Table Number | 9008 |
| MA Table ID | SCI9008 |
MA Table Description | Engineering mode; downlinks every 3rd read; maximum integration ~1605 seconds |
Changes to the technical details and other specifications presented here are expected as a part of commissioning and early operations.
Table of DROP_2_OF_3 (Resultants)
DROP_1_OF_2 Restricted Mode
This mode is intended to be used for engineering purposes and is not anticipated to be used for science observations.
Note that each engineering MA table is executed from the beginning of the sequence but may be truncated at any arbitrary resultant before reaching the end of the table. MA table truncation may result in undesirable effects in the data. The recommended minimum number of resultants for each MA table is indicated below. Users are also advised to choose a final resultant that contains a single read for optimal cosmic-ray rejection during data processing.
Table of DROP_1_OF_2 (General Properties)
| MA Table Name | DROP_1_OF_2 |
| Maximum Resultants | 255 |
| Minimum Recommended Resultants | 1 |
| WFI Observing Mode | WIM |
| Science Read Time | 3.16247 |
| Number of Reset Reads | 1 |
| Reset Read Time | 3.16248 |
| Subtract Reference Read | True |
| MA Table Number | 9009 |
| MA Table ID | SCI9009 |
MA Table Description | Engineering mode; downlinks every 2nd read; maximum integration ~1610 seconds |
Changes to the technical details and other specifications presented here are expected as a part of commissioning and early operations.
Table of DROP_1_OF_2 (Resultants)
DEFOCUS_MED_V2 Restricted Mode
This mode is intended to be used for engineering purposes and is not anticipated to be used for science observations.
Note that each engineering MA table is executed from the beginning of the sequence but may be truncated at any arbitrary resultant before reaching the end of the table. MA table truncation may result in undesirable effects in the data. The recommended minimum number of resultants for each MA table is indicated below. Users are also advised to choose a final resultant that contains a single read for optimal cosmic-ray rejection during data processing.
Table of DEFOCUS_MED_V2 (General Properties)
| MA Table Name | DEFOCUS_MED_V2 |
| Maximum Resultants | 15 |
| Minimum Recommended Resultants | 1 |
| WFI Observing Mode | DEFOCUS |
| Science Read Time | 4.40977 |
| Number of Reset Reads | 1 |
| Reset Read Time | 4.40978 |
| Subtract Reference Read | True |
| MA Table Number | 9012 |
| MA Table ID | SCI9012 |
MA Table Description | Medium defocused engineering exposure |
Changes to the technical details and other specifications presented here are expected as a part of commissioning and early operations.
Table of DEFOCUS_MED_V2 (Resultants)
| Resultant Number | Number of Skips | Number of Science Reads | Resultant Duration (s) | Integration Duration (s) | Accumulated Exposure Time (s) | Effective Exposure Time (s) |
|---|---|---|---|---|---|---|
| 1 | 0 | 1 | 4.409770 | 8.819540 | 4.409770 | 4.409770 |
| 2 | 1 | 1 | 4.409770 | 17.639080 | 13.229300 | 13.229300 |
| 3 | 3 | 1 | 4.409770 | 35.278150 | 30.868370 | 30.868370 |
| 4 | 3 | 1 | 4.409770 | 52.917220 | 48.507440 | 48.507440 |
| 5 | 3 | 1 | 4.409770 | 70.556290 | 66.146510 | 66.146510 |
| 6 | 5 | 1 | 4.409770 | 97.014890 | 92.605120 | 92.605120 |
| 7 | 7 | 1 | 4.409770 | 132.293030 | 127.883260 | 127.883260 |
| 8 | 7 | 1 | 4.409770 | 167.571170 | 163.161400 | 163.161400 |
| 9 | 7 | 1 | 4.409770 | 202.849310 | 198.439540 | 198.439540 |
| 10 | 7 | 1 | 4.409770 | 238.127450 | 233.717670 | 233.717670 |
| 11 | 7 | 1 | 4.409770 | 273.405590 | 268.995810 | 268.995810 |
| 12 | 7 | 1 | 4.409770 | 308.683730 | 304.273950 | 304.273950 |
| 13 | 7 | 1 | 4.409770 | 343.961870 | 339.552090 | 339.552090 |
| 14 | 7 | 1 | 4.409770 | 379.240010 | 374.830230 | 374.830230 |
| 15 | 7 | 1 | 4.409770 | 414.518150 | 410.108370 | 410.108370 |
Changes to the technical details and other specifications presented here are expected as a part of commissioning and early operations.
DEFOCUS_LRG_V2 Restricted Mode
This mode is intended to be used for engineering purposes and is not anticipated to be used for science observations.
Note that each engineering MA table is executed from the beginning of the sequence but may be truncated at any arbitrary resultant before reaching the end of the table. MA table truncation may result in undesirable effects in the data. The recommended minimum number of resultants for each MA table is indicated below. Users are also advised to choose a final resultant that contains a single read for optimal cosmic-ray rejection during data processing.
Table of DEFOCUS_LRG_V2 (General Properties)
| MA Table Name | DEFOCUS_LRG_V2 |
| Maximum Resultants | 15 |
| Minimum Recommended Resultants | 1 |
| WFI Observing Mode | DEFOCUS |
| Science Read Time | 6.40293 |
| Number of Reset Reads | 1 |
| Reset Read Time | 6.40294 |
| Subtract Reference Read | True |
| MA Table Number | 9013 |
| MA Table ID | SCI9013 |
MA Table Description | Large defocused engineering exposure |
Changes to the technical details and other specifications presented here are expected as a part of commissioning and early operations.
Table of DEFOCUS_LRG_V2 (Resultants)
| Resultant Number | Number of Skips | Number of Science Reads | Resultant Duration (s) | Integration Duration (s) | Accumulated Exposure Time (s) | Effective Exposure Time (s) |
|---|---|---|---|---|---|---|
| 1 | 0 | 1 | 6.402930 | 12.805860 | 6.402930 | 6.402930 |
| 2 | 1 | 1 | 6.402930 | 25.611710 | 19.208780 | 19.208780 |
| 3 | 3 | 1 | 6.402930 | 51.223420 | 44.820480 | 44.820480 |
| 4 | 3 | 1 | 6.402930 | 76.835120 | 70.432190 | 70.432190 |
| 5 | 3 | 1 | 6.402930 | 102.446830 | 96.043890 | 96.043890 |
| 6 | 5 | 1 | 6.402930 | 140.864390 | 134.461450 | 134.461450 |
| 7 | 7 | 1 | 6.402930 | 192.087800 | 185.684860 | 185.684860 |
| 8 | 7 | 1 | 6.402930 | 243.311210 | 236.908270 | 236.908270 |
| 9 | 7 | 1 | 6.402930 | 294.534620 | 288.131680 | 288.131680 |
| 10 | 7 | 1 | 6.402930 | 345.758030 | 339.355090 | 339.355090 |
| 11 | 7 | 1 | 6.402930 | 396.981440 | 390.578500 | 390.578500 |
| 12 | 7 | 1 | 6.402930 | 448.204850 | 441.801910 | 441.801910 |
| 13 | 7 | 1 | 6.402930 | 499.428250 | 493.025320 | 493.025320 |
| 14 | 7 | 1 | 6.402930 | 550.651660 | 544.248730 | 544.248730 |
| 15 | 7 | 1 | 6.402930 | 601.875070 | 595.472140 | 595.472140 |
Changes to the technical details and other specifications presented here are expected as a part of commissioning and early operations.
IM_DIAGNOSTIC Restricted Mode
This mode is intended to be used for engineering purposes and is not anticipated to be used for science observations.
Note that each engineering MA table is executed from the beginning of the sequence but may be truncated at any arbitrary resultant before reaching the end of the table. MA table truncation may result in undesirable effects in the data. The recommended minimum number of resultants for each MA table is indicated below. Users are also advised to choose a final resultant that contains a single read for optimal cosmic-ray rejection during data processing.
Table of IM_DIAGNOSTIC (General Properties)
| MA Table Name | IM_DIAGNOSTIC |
| Maximum Resultants | 300 |
| Minimum Recommended Resultants | 1 |
| WFI Observing Mode | WIM |
| Science Read Time | 3.16247 |
| Number of Reset Reads | 1 |
| Reset Read Time | 3.16248 |
| Subtract Reference Read | True |
| MA Table Number | 9010 |
| MA Table ID | SCI9010 |
MA Table Description | Diagnostic mode; down-link all reads; maximum integration ~950 seconds |
Changes to the technical details and other specifications presented here are expected as a part of commissioning and early operations.
Table of IM_DIAGNOSTIC (Resultants)
SP_DIAGNOSTIC Restricted Mode
This mode is intended to be used for engineering purposes and is not anticipated to be used for science observations.
Note that each engineering MA table is executed from the beginning of the sequence but may be truncated at any arbitrary resultant before reaching the end of the table. MA table truncation may result in undesirable effects in the data. The recommended minimum number of resultants for each MA table is indicated below. Users are also advised to choose a final resultant that contains a single read for optimal cosmic-ray rejection during data processing.
Table of SP_DIAGNOSTIC (General Properties)
| MA Table Name | SP_DIAGNOSTIC |
| Maximum Resultants | 300 |
| Minimum Recommended Resultants | 1 |
| WFI Observing Mode | WSM |
| Science Read Time | 5.14116 |
| Number of Reset Reads | 1 |
| Reset Read Time | 5.14117 |
| Subtract Reference Read | True |
| MA Table Number | 9011 |
| MA Table ID | SCI9011 |
| MA Table Description | Diagnostic mode; down-link all reads; maximum integration ~1550 seconds |
Changes to the technical details and other specifications presented here are expected as a part of commissioning and early operations.
Table of SP_DIAGNOSTIC (Resultants)
For additional questions not answered in this article, please contact the Roman Help Desk.