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SLS pipeline
============
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Instrument correction
---------------------

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Description
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``````````````````
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`csst_ms_sls_instrument` 程序包是应用于CSST无缝光谱模块的仪器效应改正程序,无缝光谱模块包含12块9k×9k探测器,每4块探测器对应1个波段,每个波段的部分仪器参数如下:
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    - GU: 660×660″ field of view from 255-400nm with a plate scale of 0.074″/pixel
    - GV: 660×660″ field of view from 400-620nm with a plate scale of 0.074″/pixel
    - GI: 660×660″ field of view from 620-1000nm with a plate scale of 0.074″/pixel
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`csst_ms_sls_instrument` 将顺序执行一系列的探测器效应改正,生成单次曝光图像预处理后的数据产品。该程序是用Python语言实现,代码地址:code_。
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.. _code: https://csst-tb.bao.ac.cn/code/csst-l1/sls/csst_ms_sls_instrument
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Input
``````````````````
`csst_ms_sls_instrument` 将从csst_common.CsstMsDataManager获取0级数据和参考文件。
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1. 0级数据: 包含一个扩展的fits文件,头文件中存放着观测天区、曝光信息、探测器信息等,具体关键字说明参见 DataModel_,扩展的数据单元存放着原始观测图像。
#. 参考文件: 仪器效应改正中所需的参考文件如下表所示。

+-----------------+----------------------------+
| Reference file  | Description                |
+=================+============================+
| Gain map        | gain array(9k×9k)          | 
+-----------------+----------------------------+
| Superbias       | superbias file(9k×9k)      | 
+-----------------+----------------------------+
| Superdark       | superdark file(9k×9k)      |
+-----------------+----------------------------+
| Superflat       | super flatfield file(9k×9k)|
+-----------------+----------------------------+
| Badpixel table  | Bad/hot Pixel table or map |
+-----------------+----------------------------+
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.. _DataModel: https://csst-tb.bao.ac.cn/code/csst-l1/csst-l1doc/-/blob/main/docs/source/sls/data_model.md
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Output
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``````````````````
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`csst_ms_sls_instrument` 生成的数据产品是包含三个扩展的fits文件,扩展内容如下表所示:
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+-----------------+---------+-------------------+
| Extension name  |  Bunit  | Comment           |
+=================+=========+===================+
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| SCI             | e-/s    | Science image     |
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+-----------------+---------+-------------------+
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| ERR             | e-/s    | Error array       |
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+-----------------+---------+-------------------+
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| DQ              | unitless| Data quality array|
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+-----------------+---------+-------------------+
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第一个扩展(SCI)的数据单元存放着仪器效应改正后的光谱图像,第二扩展(ERR)的数据单元存放着光谱图像误差,第三个扩展(DQ)的数据单元存放着光谱图像每个像素的数据质量标志位,具体参见 DQFlags_(任娟娟提供?)。仪器效应改正过程中,同时会记录下处理时间、状态信息等关键字,具体参见 DataModel_。
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.. _DQFlags: https://?
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=========== ======= ===============================================
TTYPE       TFORM   Description
=========== ======= ===============================================
BIT         integer  The bit number, starting at zero
VALUE       integer  The equivalent base-10 value of BIT
NAME        string   The mnemonic name of the data quality condition
DESCRIPTION string   A description of the data quality condition
=========== ======= ================================================
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=====  =====  =======
A      B      A and B
=====  =====  =======
False  False  False
True   False  False
False  True   False
True   True   True
=====  =====  =======
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Data Calibration Steps
``````````````````
仪器效应改正包括以下步骤:
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**DQ Initialization**
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class: csst_ms_sls_instrument.steps.DQIstep
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reference file: Badpixel table(map)、Saturation file

DQ Initialization实现两部分内容,一是利用参考文件Badpixel table或是Badpixel map对DQ扩展进行标记,该参考文件记录着存在问题的像素点,可能是探测器的坏点、热像素。二是根据Saturation file对观测数据进行判定,并在DQ扩展中标记。Saturation file的形式需要根据后续测试结果来定,如果能测出每个像素的饱和值即可做成map,现阶段用的是常值。DQ标记的详情参见DQFlags_。

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**Bias correction**

class: csst_ms_sls_instrument.steps.BiasCorrStep

**To electrons**
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class: csst_ms_sls_instrument.steps.ToElectronsStep
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**Uncertainty Initialization**

class: csst_ms_sls_instrument.steps.UncertaintyInitStep

**Dark correction**

class: csst_ms_sls_instrument.steps.DarkCorrStep

**Flatfield correction**

class: csst_ms_sls_instrument.steps.FlatCorrStep

**CR rejection**

class: csst_ms_sls_instrument.steps.CRrejStep

**To electrons/sec**

class: csst_ms_sls_instrument.steps.CPSStep

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Position calibration
---------------------

`csst_ms_sls_position` package.


API
---

TODO