From 46411febe2314eac07dcdae6fc3fff4828edabef Mon Sep 17 00:00:00 2001 From: dmggh Date: Tue, 20 Jul 2021 22:48:59 -0400 Subject: [PATCH 1/3] Add Jump documentation (RCAL-115) --- docs/roman/jump/arguments.rst | 48 ++++++++++++++++++ docs/roman/jump/description.rst | 77 +++++++++++++++++++++++++++++ docs/roman/jump/index.rst | 14 ++++++ docs/roman/jump/package_index.rst | 12 +++++ docs/roman/jump/reference_files.rst | 15 ++++++ 5 files changed, 166 insertions(+) create mode 100644 docs/roman/jump/arguments.rst create mode 100644 docs/roman/jump/description.rst create mode 100644 docs/roman/jump/index.rst create mode 100644 docs/roman/jump/package_index.rst create mode 100644 docs/roman/jump/reference_files.rst diff --git a/docs/roman/jump/arguments.rst b/docs/roman/jump/arguments.rst new file mode 100644 index 000000000..7e0fe1092 --- /dev/null +++ b/docs/roman/jump/arguments.rst @@ -0,0 +1,48 @@ +Arguments +========= + +The ``jump`` step has five optional arguments that can be set by the user: + +* ``--rejection_threshold``: A floating-point value that sets the sigma + threshold for jump detection for ramps having 5 or more groups.. In the code + sigma is determined using the read noise from the read noise reference file + and the Poisson noise (based on the median difference between samples, and the + gain reference file). Note that any noise source beyond these two that may be + present in the data will lead to an increase in the false positive rate and + thus may require an increase in the value of this parameter. The default value + of 4.0 for the rejection threshold will yield 6200 false positives for every + million pixels, if the noise model is correct. + +* ``--three_group_rejection_threshold``: A floating-point value that sets the + sigma threshold for jump detection for ramps having exactly 3 groups. The + default value is 6.0 + +* ``--four_group_rejection_threshold``: A floating-point value that sets the + sigma threshold for jump detection for ramps having exactly 4 groups. The + default value is 5.0 + +* ``--maximum_cores``: The fraction of available cores that will be + used for multi-processing in this step. The default value is 'none' which does not use + multi-processing. The other options are 'quarter', 'half', and 'all'. Note that these + fractions refer to the total available cores and on most CPUs these include physical + and virtual cores. The clock time for the step is reduced + almost linearly by the number of physical cores used on all machines. For example, on an Intel CPU with + six real cores and 6 virtual cores setting maximum_cores to 'half' results in a + decrease of a factor of six in the clock time for the step to run. Depending on the system + the clock time can also decrease even more with maximum_cores is set to 'all'. + +* ``--flag_4_neighbors``: If set to True (default is True) it will cause the four perpendicular + neighbors of all detected jumps to be flagged as a jump. This is needed because of + the inter-pixel capacitance (IPC) causing a small jump in the neighbors. The small jump + might be below the rejection threshold but will affect the slope determination of + the pixel. The step will take about 40% longer to run when this is set to True. + +* ``--max_jump_to_flag_neighbors``: A floating point value in units of sigma that limits + the flagging of neighbors. Any jump above this cutoff will not have its neighbors flagged. + The concept is that the jumps in neighbors will be above the rejection-threshold and thus + be flagged as primary jumps. The default value is 1000. + +* ``--min_jump_to_flag_neighbors``: A floating point value in units of sigma that limits + the flagging of neighbors of marginal detections. Any primary jump below this value will + not have its neighbors flagged. The goal is to prevent flagging jumps that would be too + small to significantly affect the slope determination. The default value is 10. diff --git a/docs/roman/jump/description.rst b/docs/roman/jump/description.rst new file mode 100644 index 000000000..d9fe028d8 --- /dev/null +++ b/docs/roman/jump/description.rst @@ -0,0 +1,77 @@ +Description +=========== + +Assumptions +----------- +We assume that the ``saturation`` step has already been applied to the input +science exposure, so that saturated values are appropriately flagged in the +input GROUPDQ array. We also assume that steps such as the reference pixel +correction (``refpix``) and non-linearity correction (``linearity``) have been applied, so +that the input data ramps do not have any non-linearities or noise above the modeled Poission +and read noise due to instrumental effects. The absence of any of these preceding corrections +or residual non-linearities or noise can lead to the false detection of jumps in the ramps, +due to departure from linearity. + +The ``jump`` step will automatically skip execution if the input data contain fewer +than 3 groups in the integration, because the baseline algorthim requires two first +differences to work. + +Algorithm +--------- +This routine detects jumps in an exposure by looking for outliers +in the up-the-ramp signal for each pixel in the integration within +an input exposure. On output, the GROUPDQ array is updated with the DQ flag +"JUMP_DET" to indicate the location of each jump that was found. +In addition, any pixels that have non-positive or NaN values in the gain +reference file will have DQ flags "NO_GAIN_VALUE" and "DO_NOT_USE" set in the +output PIXELDQ array. +The SCI and ERR arrays of the input data are not modified. + +The current implementation uses the two-point difference method described +in Anderson&Gordon2011_. + +Two-Point Difference Method +^^^^^^^^^^^^^^^^^^^^^^^^^^^ +The two-point difference method is applied to the integration as follows: + +* Compute the first differences for each pixel (the difference between + adjacent groups) +* Compute the clipped (dropping the largest difference) median of the first differences for each pixel. +* Use the median to estimate the Poisson noise for each group and combine it + with the read noise to arrive at an estimate of the total expected noise for + each difference. +* Compute the "difference ratio" as the difference between the first differences + of each group and the median, divided by the expected noise. +* If the largest "difference ratio" is greater than the rejection threshold, + flag the group corresponding to that ratio as having a jump. +* If a jump is found in a given pixel, iterate the above steps with the + jump-impacted group excluded, looking for additional lower-level jumps + that still exceed the rejection threshold. +* Stop iterating on a given pixel when no new jumps are found or only one difference remains. +* If the there are only three differences (four groups), the standard median is used rather than + the clipped median. +* If there are only two differences (three groups), the smallest one is compared to the larger + one and if the larger one is above a threshold, it is flagged as a jump. + +Note that any ramp values flagged as SATURATED in the input GROUPDQ array +are not used in any of the above calculations and hence will never be +marked as containing a jump. + +Multiprocessing +=============== +This step has the option of running in multiprocessing mode. In that mode it will +split the input data cube into a number of row slices based on the number of available +cores on the host computer and the value of the max_cores input parameter. By +default the step runs on a single processor. At the other extreme if max_cores is +set to 'all', it will use all available cores (real and virtual). Testing has shown +a reduction in the elapsed time for the step proportional to the number of real +cores used. Using the virtual cores also reduces the elasped time but at a slightly +lower rate than the real cores. + +If multiprocessing is requested the input cube will be divided into a number of +slices in the row dimension (with the last slice being slightly larger, if needed). +The slices are then sent to twopoint_difference.py by detect_jumps. After all the +slices have finished processing, detect_jumps assembles the output group_dq cube +from the slices. + +.. _Anderson&Gordon2011: https://ui.adsabs.harvard.edu/abs/2011PASP..123.1237A diff --git a/docs/roman/jump/index.rst b/docs/roman/jump/index.rst new file mode 100644 index 000000000..bafe8c4d0 --- /dev/null +++ b/docs/roman/jump/index.rst @@ -0,0 +1,14 @@ +.. _jump_step: + +============== +Jump Detection +============== + +.. toctree:: + :maxdepth: 2 + + description.rst + arguments.rst + reference_files.rst + +.. automodapi:: romancal.jump diff --git a/docs/roman/jump/package_index.rst b/docs/roman/jump/package_index.rst new file mode 100644 index 000000000..7c543432e --- /dev/null +++ b/docs/roman/jump/package_index.rst @@ -0,0 +1,12 @@ +============= +Package Index +============= +.. toctree:: + :maxdepth: 2 + + datamodels/index.rst + dark_current/index.rst + flatfield/index.rst + gain_scale/index.rst + jump/index.rst + references_general/index.rst diff --git a/docs/roman/jump/reference_files.rst b/docs/roman/jump/reference_files.rst new file mode 100644 index 000000000..de77cc0f2 --- /dev/null +++ b/docs/roman/jump/reference_files.rst @@ -0,0 +1,15 @@ +Reference File Types +===================== + +The ``jump`` step uses two reference files: :ref:`GAIN ` +and :ref:`READNOISE `. +The GAIN reference file is used to temporarily convert pixel values in +the ``jump`` step from units of DN to electrons. +The READNOISE reference file is used in estimating the expected noise +in each pixel. +Both are necessary for proper computation of noise estimates within the +``jump`` step. + +:ref:`GAIN ` + +:ref:`READNOISE ` From 11e9a8fa5d608984cda94767ea895ea67e413e7a Mon Sep 17 00:00:00 2001 From: dmggh Date: Wed, 21 Jul 2021 17:07:54 -0400 Subject: [PATCH 2/3] Added file to wrong directory --- docs/roman/jump/arguments.rst | 48 ------------------ docs/roman/jump/description.rst | 77 ----------------------------- docs/roman/jump/index.rst | 14 ------ docs/roman/jump/package_index.rst | 12 ----- docs/roman/jump/reference_files.rst | 15 ------ 5 files changed, 166 deletions(-) delete mode 100644 docs/roman/jump/arguments.rst delete mode 100644 docs/roman/jump/description.rst delete mode 100644 docs/roman/jump/index.rst delete mode 100644 docs/roman/jump/package_index.rst delete mode 100644 docs/roman/jump/reference_files.rst diff --git a/docs/roman/jump/arguments.rst b/docs/roman/jump/arguments.rst deleted file mode 100644 index 7e0fe1092..000000000 --- a/docs/roman/jump/arguments.rst +++ /dev/null @@ -1,48 +0,0 @@ -Arguments -========= - -The ``jump`` step has five optional arguments that can be set by the user: - -* ``--rejection_threshold``: A floating-point value that sets the sigma - threshold for jump detection for ramps having 5 or more groups.. In the code - sigma is determined using the read noise from the read noise reference file - and the Poisson noise (based on the median difference between samples, and the - gain reference file). Note that any noise source beyond these two that may be - present in the data will lead to an increase in the false positive rate and - thus may require an increase in the value of this parameter. The default value - of 4.0 for the rejection threshold will yield 6200 false positives for every - million pixels, if the noise model is correct. - -* ``--three_group_rejection_threshold``: A floating-point value that sets the - sigma threshold for jump detection for ramps having exactly 3 groups. The - default value is 6.0 - -* ``--four_group_rejection_threshold``: A floating-point value that sets the - sigma threshold for jump detection for ramps having exactly 4 groups. The - default value is 5.0 - -* ``--maximum_cores``: The fraction of available cores that will be - used for multi-processing in this step. The default value is 'none' which does not use - multi-processing. The other options are 'quarter', 'half', and 'all'. Note that these - fractions refer to the total available cores and on most CPUs these include physical - and virtual cores. The clock time for the step is reduced - almost linearly by the number of physical cores used on all machines. For example, on an Intel CPU with - six real cores and 6 virtual cores setting maximum_cores to 'half' results in a - decrease of a factor of six in the clock time for the step to run. Depending on the system - the clock time can also decrease even more with maximum_cores is set to 'all'. - -* ``--flag_4_neighbors``: If set to True (default is True) it will cause the four perpendicular - neighbors of all detected jumps to be flagged as a jump. This is needed because of - the inter-pixel capacitance (IPC) causing a small jump in the neighbors. The small jump - might be below the rejection threshold but will affect the slope determination of - the pixel. The step will take about 40% longer to run when this is set to True. - -* ``--max_jump_to_flag_neighbors``: A floating point value in units of sigma that limits - the flagging of neighbors. Any jump above this cutoff will not have its neighbors flagged. - The concept is that the jumps in neighbors will be above the rejection-threshold and thus - be flagged as primary jumps. The default value is 1000. - -* ``--min_jump_to_flag_neighbors``: A floating point value in units of sigma that limits - the flagging of neighbors of marginal detections. Any primary jump below this value will - not have its neighbors flagged. The goal is to prevent flagging jumps that would be too - small to significantly affect the slope determination. The default value is 10. diff --git a/docs/roman/jump/description.rst b/docs/roman/jump/description.rst deleted file mode 100644 index d9fe028d8..000000000 --- a/docs/roman/jump/description.rst +++ /dev/null @@ -1,77 +0,0 @@ -Description -=========== - -Assumptions ------------ -We assume that the ``saturation`` step has already been applied to the input -science exposure, so that saturated values are appropriately flagged in the -input GROUPDQ array. We also assume that steps such as the reference pixel -correction (``refpix``) and non-linearity correction (``linearity``) have been applied, so -that the input data ramps do not have any non-linearities or noise above the modeled Poission -and read noise due to instrumental effects. The absence of any of these preceding corrections -or residual non-linearities or noise can lead to the false detection of jumps in the ramps, -due to departure from linearity. - -The ``jump`` step will automatically skip execution if the input data contain fewer -than 3 groups in the integration, because the baseline algorthim requires two first -differences to work. - -Algorithm ---------- -This routine detects jumps in an exposure by looking for outliers -in the up-the-ramp signal for each pixel in the integration within -an input exposure. On output, the GROUPDQ array is updated with the DQ flag -"JUMP_DET" to indicate the location of each jump that was found. -In addition, any pixels that have non-positive or NaN values in the gain -reference file will have DQ flags "NO_GAIN_VALUE" and "DO_NOT_USE" set in the -output PIXELDQ array. -The SCI and ERR arrays of the input data are not modified. - -The current implementation uses the two-point difference method described -in Anderson&Gordon2011_. - -Two-Point Difference Method -^^^^^^^^^^^^^^^^^^^^^^^^^^^ -The two-point difference method is applied to the integration as follows: - -* Compute the first differences for each pixel (the difference between - adjacent groups) -* Compute the clipped (dropping the largest difference) median of the first differences for each pixel. -* Use the median to estimate the Poisson noise for each group and combine it - with the read noise to arrive at an estimate of the total expected noise for - each difference. -* Compute the "difference ratio" as the difference between the first differences - of each group and the median, divided by the expected noise. -* If the largest "difference ratio" is greater than the rejection threshold, - flag the group corresponding to that ratio as having a jump. -* If a jump is found in a given pixel, iterate the above steps with the - jump-impacted group excluded, looking for additional lower-level jumps - that still exceed the rejection threshold. -* Stop iterating on a given pixel when no new jumps are found or only one difference remains. -* If the there are only three differences (four groups), the standard median is used rather than - the clipped median. -* If there are only two differences (three groups), the smallest one is compared to the larger - one and if the larger one is above a threshold, it is flagged as a jump. - -Note that any ramp values flagged as SATURATED in the input GROUPDQ array -are not used in any of the above calculations and hence will never be -marked as containing a jump. - -Multiprocessing -=============== -This step has the option of running in multiprocessing mode. In that mode it will -split the input data cube into a number of row slices based on the number of available -cores on the host computer and the value of the max_cores input parameter. By -default the step runs on a single processor. At the other extreme if max_cores is -set to 'all', it will use all available cores (real and virtual). Testing has shown -a reduction in the elapsed time for the step proportional to the number of real -cores used. Using the virtual cores also reduces the elasped time but at a slightly -lower rate than the real cores. - -If multiprocessing is requested the input cube will be divided into a number of -slices in the row dimension (with the last slice being slightly larger, if needed). -The slices are then sent to twopoint_difference.py by detect_jumps. After all the -slices have finished processing, detect_jumps assembles the output group_dq cube -from the slices. - -.. _Anderson&Gordon2011: https://ui.adsabs.harvard.edu/abs/2011PASP..123.1237A diff --git a/docs/roman/jump/index.rst b/docs/roman/jump/index.rst deleted file mode 100644 index bafe8c4d0..000000000 --- a/docs/roman/jump/index.rst +++ /dev/null @@ -1,14 +0,0 @@ -.. _jump_step: - -============== -Jump Detection -============== - -.. toctree:: - :maxdepth: 2 - - description.rst - arguments.rst - reference_files.rst - -.. automodapi:: romancal.jump diff --git a/docs/roman/jump/package_index.rst b/docs/roman/jump/package_index.rst deleted file mode 100644 index 7c543432e..000000000 --- a/docs/roman/jump/package_index.rst +++ /dev/null @@ -1,12 +0,0 @@ -============= -Package Index -============= -.. toctree:: - :maxdepth: 2 - - datamodels/index.rst - dark_current/index.rst - flatfield/index.rst - gain_scale/index.rst - jump/index.rst - references_general/index.rst diff --git a/docs/roman/jump/reference_files.rst b/docs/roman/jump/reference_files.rst deleted file mode 100644 index de77cc0f2..000000000 --- a/docs/roman/jump/reference_files.rst +++ /dev/null @@ -1,15 +0,0 @@ -Reference File Types -===================== - -The ``jump`` step uses two reference files: :ref:`GAIN ` -and :ref:`READNOISE `. -The GAIN reference file is used to temporarily convert pixel values in -the ``jump`` step from units of DN to electrons. -The READNOISE reference file is used in estimating the expected noise -in each pixel. -Both are necessary for proper computation of noise estimates within the -``jump`` step. - -:ref:`GAIN ` - -:ref:`READNOISE ` From c51c89da88534f3dbff2c112b3605ad183cb4712 Mon Sep 17 00:00:00 2001 From: dmggh Date: Wed, 21 Jul 2021 17:23:42 -0400 Subject: [PATCH 3/3] Add Jump documentation (RCAL-115) --- docs/roman/jump/arguments.rst | 48 ++++++++++++++++++ docs/roman/jump/description.rst | 77 +++++++++++++++++++++++++++++ docs/roman/jump/index.rst | 14 ++++++ docs/roman/jump/reference_files.rst | 15 ++++++ docs/roman/package_index.rst | 1 + 5 files changed, 155 insertions(+) create mode 100644 docs/roman/jump/arguments.rst create mode 100644 docs/roman/jump/description.rst create mode 100644 docs/roman/jump/index.rst create mode 100644 docs/roman/jump/reference_files.rst diff --git a/docs/roman/jump/arguments.rst b/docs/roman/jump/arguments.rst new file mode 100644 index 000000000..7e0fe1092 --- /dev/null +++ b/docs/roman/jump/arguments.rst @@ -0,0 +1,48 @@ +Arguments +========= + +The ``jump`` step has five optional arguments that can be set by the user: + +* ``--rejection_threshold``: A floating-point value that sets the sigma + threshold for jump detection for ramps having 5 or more groups.. In the code + sigma is determined using the read noise from the read noise reference file + and the Poisson noise (based on the median difference between samples, and the + gain reference file). Note that any noise source beyond these two that may be + present in the data will lead to an increase in the false positive rate and + thus may require an increase in the value of this parameter. The default value + of 4.0 for the rejection threshold will yield 6200 false positives for every + million pixels, if the noise model is correct. + +* ``--three_group_rejection_threshold``: A floating-point value that sets the + sigma threshold for jump detection for ramps having exactly 3 groups. The + default value is 6.0 + +* ``--four_group_rejection_threshold``: A floating-point value that sets the + sigma threshold for jump detection for ramps having exactly 4 groups. The + default value is 5.0 + +* ``--maximum_cores``: The fraction of available cores that will be + used for multi-processing in this step. The default value is 'none' which does not use + multi-processing. The other options are 'quarter', 'half', and 'all'. Note that these + fractions refer to the total available cores and on most CPUs these include physical + and virtual cores. The clock time for the step is reduced + almost linearly by the number of physical cores used on all machines. For example, on an Intel CPU with + six real cores and 6 virtual cores setting maximum_cores to 'half' results in a + decrease of a factor of six in the clock time for the step to run. Depending on the system + the clock time can also decrease even more with maximum_cores is set to 'all'. + +* ``--flag_4_neighbors``: If set to True (default is True) it will cause the four perpendicular + neighbors of all detected jumps to be flagged as a jump. This is needed because of + the inter-pixel capacitance (IPC) causing a small jump in the neighbors. The small jump + might be below the rejection threshold but will affect the slope determination of + the pixel. The step will take about 40% longer to run when this is set to True. + +* ``--max_jump_to_flag_neighbors``: A floating point value in units of sigma that limits + the flagging of neighbors. Any jump above this cutoff will not have its neighbors flagged. + The concept is that the jumps in neighbors will be above the rejection-threshold and thus + be flagged as primary jumps. The default value is 1000. + +* ``--min_jump_to_flag_neighbors``: A floating point value in units of sigma that limits + the flagging of neighbors of marginal detections. Any primary jump below this value will + not have its neighbors flagged. The goal is to prevent flagging jumps that would be too + small to significantly affect the slope determination. The default value is 10. diff --git a/docs/roman/jump/description.rst b/docs/roman/jump/description.rst new file mode 100644 index 000000000..d9fe028d8 --- /dev/null +++ b/docs/roman/jump/description.rst @@ -0,0 +1,77 @@ +Description +=========== + +Assumptions +----------- +We assume that the ``saturation`` step has already been applied to the input +science exposure, so that saturated values are appropriately flagged in the +input GROUPDQ array. We also assume that steps such as the reference pixel +correction (``refpix``) and non-linearity correction (``linearity``) have been applied, so +that the input data ramps do not have any non-linearities or noise above the modeled Poission +and read noise due to instrumental effects. The absence of any of these preceding corrections +or residual non-linearities or noise can lead to the false detection of jumps in the ramps, +due to departure from linearity. + +The ``jump`` step will automatically skip execution if the input data contain fewer +than 3 groups in the integration, because the baseline algorthim requires two first +differences to work. + +Algorithm +--------- +This routine detects jumps in an exposure by looking for outliers +in the up-the-ramp signal for each pixel in the integration within +an input exposure. On output, the GROUPDQ array is updated with the DQ flag +"JUMP_DET" to indicate the location of each jump that was found. +In addition, any pixels that have non-positive or NaN values in the gain +reference file will have DQ flags "NO_GAIN_VALUE" and "DO_NOT_USE" set in the +output PIXELDQ array. +The SCI and ERR arrays of the input data are not modified. + +The current implementation uses the two-point difference method described +in Anderson&Gordon2011_. + +Two-Point Difference Method +^^^^^^^^^^^^^^^^^^^^^^^^^^^ +The two-point difference method is applied to the integration as follows: + +* Compute the first differences for each pixel (the difference between + adjacent groups) +* Compute the clipped (dropping the largest difference) median of the first differences for each pixel. +* Use the median to estimate the Poisson noise for each group and combine it + with the read noise to arrive at an estimate of the total expected noise for + each difference. +* Compute the "difference ratio" as the difference between the first differences + of each group and the median, divided by the expected noise. +* If the largest "difference ratio" is greater than the rejection threshold, + flag the group corresponding to that ratio as having a jump. +* If a jump is found in a given pixel, iterate the above steps with the + jump-impacted group excluded, looking for additional lower-level jumps + that still exceed the rejection threshold. +* Stop iterating on a given pixel when no new jumps are found or only one difference remains. +* If the there are only three differences (four groups), the standard median is used rather than + the clipped median. +* If there are only two differences (three groups), the smallest one is compared to the larger + one and if the larger one is above a threshold, it is flagged as a jump. + +Note that any ramp values flagged as SATURATED in the input GROUPDQ array +are not used in any of the above calculations and hence will never be +marked as containing a jump. + +Multiprocessing +=============== +This step has the option of running in multiprocessing mode. In that mode it will +split the input data cube into a number of row slices based on the number of available +cores on the host computer and the value of the max_cores input parameter. By +default the step runs on a single processor. At the other extreme if max_cores is +set to 'all', it will use all available cores (real and virtual). Testing has shown +a reduction in the elapsed time for the step proportional to the number of real +cores used. Using the virtual cores also reduces the elasped time but at a slightly +lower rate than the real cores. + +If multiprocessing is requested the input cube will be divided into a number of +slices in the row dimension (with the last slice being slightly larger, if needed). +The slices are then sent to twopoint_difference.py by detect_jumps. After all the +slices have finished processing, detect_jumps assembles the output group_dq cube +from the slices. + +.. _Anderson&Gordon2011: https://ui.adsabs.harvard.edu/abs/2011PASP..123.1237A diff --git a/docs/roman/jump/index.rst b/docs/roman/jump/index.rst new file mode 100644 index 000000000..bafe8c4d0 --- /dev/null +++ b/docs/roman/jump/index.rst @@ -0,0 +1,14 @@ +.. _jump_step: + +============== +Jump Detection +============== + +.. toctree:: + :maxdepth: 2 + + description.rst + arguments.rst + reference_files.rst + +.. automodapi:: romancal.jump diff --git a/docs/roman/jump/reference_files.rst b/docs/roman/jump/reference_files.rst new file mode 100644 index 000000000..de77cc0f2 --- /dev/null +++ b/docs/roman/jump/reference_files.rst @@ -0,0 +1,15 @@ +Reference File Types +===================== + +The ``jump`` step uses two reference files: :ref:`GAIN ` +and :ref:`READNOISE `. +The GAIN reference file is used to temporarily convert pixel values in +the ``jump`` step from units of DN to electrons. +The READNOISE reference file is used in estimating the expected noise +in each pixel. +Both are necessary for proper computation of noise estimates within the +``jump`` step. + +:ref:`GAIN ` + +:ref:`READNOISE ` diff --git a/docs/roman/package_index.rst b/docs/roman/package_index.rst index a35bd6c98..7c543432e 100644 --- a/docs/roman/package_index.rst +++ b/docs/roman/package_index.rst @@ -8,4 +8,5 @@ Package Index dark_current/index.rst flatfield/index.rst gain_scale/index.rst + jump/index.rst references_general/index.rst