feat: resolves #4

README.md

@@ -49,6 +49,18 @@ Some extensions may specify more specific rules for this field.
 
 This field superceedes the `sar:product_type` field.
 
+#### product:acquisition_type
+
+The product acquisition type in this extension is an enumeration text that providers can use to descibe their product types.
+As described in the [specifications](https://docs.ogc.org/is/10-157r4/10-157r4.html):
+
+> Used to distinguish at a high level the appropriateness of the acquisition for "general" use, whether the product is a nominal acquisition, special calibration product or other.
+
+Admitted values are:
+ - `nominal`
+ - `calibration`
+ - `other`
+
 #### Timeliness
 
 Below you can find an example that shows how the timeliness fields could be used.

examples/collection.json

@@ -39,7 +39,8 @@
     ],
     "product:timeliness_category": [
       "NRT"
-    ]
+    ],
+    "product:acquisition_type": "calibration"
   },
   "links": [
     {

examples/item.json

@@ -16,7 +16,8 @@
     ],
     "product:type": "GRD",
     "product:timeliness": "PT3H",
-    "product:timeliness_category": "NRT"
+    "product:timeliness_category": "NRT",
+    "product:acquisition_type": "nominal"
   },
   "geometry": {
     "type": "Polygon",

json-schema/schema.json

@@ -119,6 +119,9 @@
         },
         "product:timeliness_category": {
           "$ref": "#/definitions/product:timeliness_category"
+        },
+        "product:acquisition_type": {
+          "$ref": "#/definitions/product:acquisition_type"
         }
       },
       "patternProperties": {
@@ -137,6 +140,10 @@
     "product:timeliness_category": {
       "type": "string"
     },
+    "product:acquisition_type": {
+      "type": "string",
+      "enum": [ "nominal", "calibration", "other" ]
+    },
     "json_schema": {
       "$comment": "JSON Schema",
       "type": "object"