RAD-136 Add Slope and Error to Dark (#323)

* Added slopes to dark.

* Updated Changelog.

CHANGES.rst

@@ -1,7 +1,7 @@
 0.17.2 (unreleased)
 -------------------
 
--
+- Added Slope and Error to Dark reference schema. [#323]
 
 0.17.1 (2023-08-03)
 -------------------

src/rad/resources/schemas/reference_files/dark-1.0.0.yaml

@@ -69,7 +69,33 @@ properties:
       unit:
         tag: tag:astropy.org:astropy/units/unit-1.0.0
         enum: ["DN"]
+  dark_slope:
+    title: Dark current slope array
+    description: |
+       The dark current slope array represents the slope of the
+       integrated number of counts due to the accumulation of dark
+       current electrons in the pixels for slope fitting purposes.
+    tag: tag:stsci.edu:asdf/unit/quantity-1.1.0
+    properties:
+      value:
+        tag: tag:stsci.edu:asdf/core/ndarray-1.0.0
+        datatype: float32
+        ndim: 2
+      unit:
+        tag: tag:astropy.org:astropy/units/unit-1.0.0
+        enum: ["DN / s"]
+  dark_slope_error:
+    title: Uncertainty in dark current slope array
+    tag: tag:stsci.edu:asdf/unit/quantity-1.1.0
+    properties:
+      value:
+        tag: tag:stsci.edu:asdf/core/ndarray-1.0.0
+        datatype: float32
+        ndim: 2
+      unit:
+        tag: tag:astropy.org:astropy/units/unit-1.0.0
+        enum: ["DN / s"]
 required: [meta, data, dq, err]
 flowStyle: block
-propertyOrder: [meta, data, dq, err]
+propertyOrder: [meta, data, dq, err, dark_slope, dark_slope_error]
 ...