Add first draft of Optical

README.md

@@ -1,4 +1,4 @@
-# CEOS ARD Extension Specification
+# CEOS-ARD Extension Specification
 
 - **Title:** CEOS-ARD
 - **Identifier:** <https://stac-extensions.github.io/ceos-ard/v0.2.0/schema.json>
@@ -8,7 +8,7 @@
 - **Owner**: @m-mohr
 
 This document explains the CEOS-ARD Extension to the [SpatioTemporal Asset Catalog](https://github.com/radiantearth/stac-spec) (STAC) specification.
-It specifies how to create STAC Items and Collections that comply to the various CEOS ARD product family specifications.
+It specifies how to create STAC Items and Collections that comply to the various CEOS-ARD product family specifications.
 It is planned that this extension supersedes the existing [CARD4L extension](https://github.com/stac-extensions/card4l),
 which itself is planned to be deprecated.
 
@@ -35,6 +35,10 @@ The fields in the table below can be used in these parts of STAC documents:
 | ceos_ard:specification         | string    | **REQUIRED.** The CARD4L product family specification implemented. |
 | ceos_ard:specification_version | string    | **REQUIRED.** The CEOS-ARD product family specification version. |
 
+Additional requirements are specified in the mapping documents:
+
+- [Optical](optical/README.md)
+
 ### Additional Field Information
 
 #### ceos_ard:specification
@@ -44,6 +48,7 @@ The following values are supported:
 **Type 'Optical':**
 - `optical-ar`: Aquatic Reflectance
 - `optical-lidar-tcth`: LiDAR Terrain and Canopy Top Height
+- `optical-nighttime-lights-sr`: Nighttime Lights Surface Radiance
 - `optical-sr`: Surface Reflectance
 - `optical-st`: Surface Temperature