add SVOM/MXT localization notices (N2m)

gcn/notices/svom/mxt/localization.example.json

@@ -0,0 +1,18 @@
+{
+  "$schema": "https://gcn.nasa.gov/schema/main/gcn/notices/svom/mxt/localization.schema.json",
+  "mission": "SVOM",
+  "instrument": "MXT",
+  "messenger": "EM",
+  "alert_datetime": "2024-02-22T08:51:55",
+  "alert_tense": "current",
+  "alert_type": "initial",
+  "id": ["sb24022203"],
+  "record_number": 1,
+  "trigger_time": "2024-02-22T08:51:31.320000",
+  "image_snr": 25.67,
+  "mean_flux": 5.1,
+  "flux_error": 0.2,
+  "ra": 143.2478,
+  "dec": -68.0289,
+  "ra_dec_error": 0.1
+}

gcn/notices/svom/mxt/localization.schema.json

@@ -0,0 +1,32 @@
+{
+  "$id": "https://gcn.nasa.gov/schema/main/gcn/notices/svom/mxt/localization.schema.json",
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "type": "object",
+  "unevaluatedProperties": false,
+  "title": "SVOM/MXT localisation parameters",
+  "description": "MXT refined localisation after a slew of the SVOM platform on an ECLAIRs triggered source",
+  "allOf": [
+    { "$ref": "../../core/AdditionalInfo.schema.json" },
+    { "$ref": "../../core/Alert.schema.json" },
+    { "$ref": "../../core/DateTime.schema.json" },
+    { "$ref": "../../core/Event.schema.json" },
+    { "$ref": "../../core/Localization.schema.json" },
+    { "$ref": "../../core/Reporter.schema.json" },
+    { "$ref": "../../core/Statistics.schema.json" }
+  ],
+  "properties": {
+    "$schema": true,
+    "mean_flux": {
+      "type": "number",
+      "description": "Mean flux of the detection [erg.cm^-2]"
+    },
+    "flux_error": {
+      "type": "number",
+      "description": "Error on the mean flux of the detection [erg.cm^-2]"
+    },
+    "use_VT_attitude": {
+      "type": "boolean",
+      "description": "Whether the platform stabilisation process uses the VT instead of the standard star tracker. This leads to an improved localization."
+    }
+  }
+}