From 9f1ea6446ecb4d6d7ff54a9a5cedc574a5b1bc91 Mon Sep 17 00:00:00 2001
From: Athish Thiruvengadam <athisht2@illinois.edu>
Date: Mon, 16 Sep 2024 17:44:40 -0500
Subject: [PATCH] LVK schema and example JSONs

---
 gcn/notices/lvk/alert.example.json | 38 ++++++++++++
 gcn/notices/lvk/alert.schema.json  | 95 ++++++++++++++++++++++++++++++
 2 files changed, 133 insertions(+)
 create mode 100644 gcn/notices/lvk/alert.example.json
 create mode 100644 gcn/notices/lvk/alert.schema.json

diff --git a/gcn/notices/lvk/alert.example.json b/gcn/notices/lvk/alert.example.json
new file mode 100644
index 00000000..c730b21e
--- /dev/null
+++ b/gcn/notices/lvk/alert.example.json
@@ -0,0 +1,38 @@
+{
+  "$schema": "https://gcn.nasa.gov/schema/main/gcn/notices/lvk/alert.schema.json",
+  "alert_type": "update",
+  "alert_datetime": "2018-11-01T22:36:25Z",
+  "id": ["MS181101ab"],
+  "trigger_time": "2018-11-01T22:22:46.654Z",
+  "far": 9.11069936486e-14,
+  "significant": true,
+  "detector_status": {
+    "H1": "triggered",
+    "L1": "triggered",
+    "V1": "triggered"
+  },
+  "healpix_file": "U0lNUExFICA9ICAgICAgICAgICAgICAgICAgICBUIC8gY29uZm...",
+  "healpix_url": "https://gracedb.ligo.org/api/superevents/MS181101ab/files/bayestar.multiorder.fits,0",
+  "search": "MDC",
+  "group": "CBC",
+  "pipeline": "gstlal",
+  "duration": null,
+  "central_frequency": null,
+  "properties": { "HasNS": 0.95, "HasRemnant": 0.91, "HasMassGap": 0.01 },
+  "classification": {
+    "BNS": 0.95,
+    "NSBH": 0.01,
+    "BBH": 0.03,
+    "Terrestrial": 0.01
+  },
+  "external_coincidence": {
+    "gcn_notice_id": 524666471,
+    "ivorn": "ivo://nasa.gsfc.gcn/Fermi#GBM_Fin_Pos2017-08-17T12:41:06.47_524666471_0-389",
+    "observatory": "Fermi",
+    "search": "GRB",
+    "time_difference": 2.02,
+    "time_coincidence_far": 2.14387838137e-14,
+    "time_sky_position_coincidence_far": 6.410749524018777e-16,
+    "combined_skymap": "U0lNUExFICA9ICAgICAgICAgICAgICAgICAgICBUIC8gY29uZm..."
+  }
+}
diff --git a/gcn/notices/lvk/alert.schema.json b/gcn/notices/lvk/alert.schema.json
new file mode 100644
index 00000000..fdd83626
--- /dev/null
+++ b/gcn/notices/lvk/alert.schema.json
@@ -0,0 +1,95 @@
+{
+  "$id": "https://gcn.nasa.gov/schema/main/gcn/notices/lvk/alert.schema.json",
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "type": "object",
+  "unevaluatedProperties": false,
+  "title": "Alert",
+  "description": "LIGO-Virgo Collaboration Gravitational Wave Alert",
+  "allOf": [
+    { "$ref": "../core/Alert.schema.json" },
+    { "$ref": "../core/DateTime.schema.json" },
+    { "$ref": "../core/Event.schema.json" },
+    { "$ref": "../core/Localization.schema.json" },
+    { "$ref": "../core/Statistics.schema.json" }
+  ],
+  "properties": {
+    "$schema": true,
+    "detector_status": {
+      "type": "object",
+      "properties": {
+        "H1": { "$ref": "../core/DetectorStatus.schema.json" },
+        "L1": { "$ref": "../core/DetectorStatus.schema.json" },
+        "V1": { "$ref": "../core/DetectorStatus.schema.json" }
+      }
+    },
+    "duration": {
+      "type": ["number", "null"],
+      "description": "Duration of GW signal. Defined only for the burst class of events."
+    },
+    "central_frequency": {
+      "type": ["number", "null"],
+      "description": "Peak frequency of GW signal in Hz. Defined only for the burst class of events."
+    },
+    "pipeline": {
+      "type": "string",
+      "description": "The pipeline used to process the triggers."
+    },
+    "search": {
+      "type": "string",
+      "description": "The search method used for the GW event."
+    },
+    "group": {
+      "type": "string",
+      "description": "The class of GW trigger: CBC or Burst."
+    },
+    "significant": {
+      "type": "boolean",
+      "description": "Whether the far is above a certain threshold."
+    },
+    "external_coincidence": {
+      "anyOf": [
+        { "type": "null" },
+        {
+          "type": "object",
+          "description": "Coincidence with a non-GW event sent through GCN.",
+          "properties": {
+            "gcn_notice_id": {
+              "type": "number",
+              "description": "ID used by GCN to identify external event."
+            },
+            "ivorn": {
+              "type": "string",
+              "description": "External IVORN identification field."
+            },
+            "observatory": {
+              "type": "string",
+              "description": "The mission which detected the external event."
+            },
+            "search": {
+              "type": "string",
+              "description": "The search method used to find the external event."
+            },
+            "time_difference": {
+              "type": "number",
+              "description": "Time between GW source and external event [secs]"
+            },
+            "time_coincidence_far": {
+              "type": "number",
+              "description": "Estimated coincidence false alarm rate using just timing [Hz]"
+            },
+            "time_sky_position_coincidence_far": {
+              "type": "number",
+              "description": "Estimated coincidence false alarm rate using timing and sky position [Hz]"
+            },
+            "combined_skymap": {
+              "type": "string",
+              "contentEncoding": "base64",
+              "contentMediaType": "image/fits",
+              "description": "The GW skymap and the external coincidence skymap combined in a multi-order FITS file as a Base64-encoded string."
+            }
+          }
+        }
+      ]
+    }
+  }
+}