diff --git a/Certificate/schema.json b/Certificate/schema.json
index a33360a..b554aef 100644
--- a/Certificate/schema.json
+++ b/Certificate/schema.json
@@ -1,145 +1,39 @@
 {
-  "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$schemaVersion": "0.3.4",
-  "modelTags": "IUDX",
-  "$id": "https://smart-data-models.github.io/dataModel.Weather/WeatherObserved/schema.json",
-  "title": "Weather Observed schema - Smart Data Models",
-  "description": "An observation of weather conditions at a certain place and time. This data model has been developed in cooperation with mobile operators and the GSMA.",
-  "type": "object",
-  "allOf": [
-    {
-      "$ref": "https://smart-data-models.github.io/data-models/common-schema.json#/definitions/GSMA-Commons"
-    },
-    {
-      "$ref": "https://smart-data-models.github.io/data-models/common-schema.json#/definitions/Location-Commons"
-    },
-    {
-      "$ref": "https://smart-data-models.github.io/dataModel.Weather/weather-schema.json#/definitions/Weather-Commons"
-    },
-    {
-      "properties": {
-        "type": {
-          "type": "string",
-          "enum": [
-            "WeatherObserved"
-          ],
-          "description": "Property. NGSI Entity type. It has to be WeatherObserved"
-        },
-        "dateObserved": {
-          "$ref": "https://smart-data-models.github.io/data-models/common-schema.json#/definitions/dateObserved"
-        },
-        "precipitation": {
-          "type": "number",
-          "minimum": 0,
-          "description": "Property. Model:'https://schema.org/Number'. Amount of water rain registered. Units:'Liters per square meter'. "
-        },
-        "solarRadiation": {
-          "type": "number",
-          "minimum": 0,
-          "description": "Property. Model:'https://schema.org/Number'. The solar radiation observed measured in Watts per square. Units:'w/m2'"
-        },
-        "directIrradiation": {
-          "type": "number",
-          "minimum": 0,
-          "description": "Property. Model:'https://schema.org/Number'. Direct irradiance is the part of the solar irradiance that directly reaches a surface. Units:'w/m2'"
-        },
-        "diffuseIrradiation": {
-          "type": "number",
-          "minimum": 0,
-          "description": "Property. Model:'https://schema.org/Number'. Diffuse irradiance is the part of the solar irradiance that is scattered by the atmosphere. Units:'w/m2'"
-        },
-        "pressureTendency": {
-          "oneOf": [
-            {
-              "type": "string",
-              "enum": [
-                "falling",
-                "raising",
-                "steady"
-              ]
-            },
-            {
-              "type": "number"
+    "$schema": "http://json-schema.org/schema#",
+    "$schemaVersion": "0.0.1",
+    "$id": "https://smart-data-models.github.io/dataModel.ERA/Certificate/schema.json",
+    "modelTags": "ERA vocabulary, railway, train",
+    "license": "https://smart-data-models.github.io/dataModel.ERA/Certificate/LICENSE.md",
+    "derivedFrom": "http://data.europa.eu/949/Certificate",
+    "type": "object",
+    "allOf": [
+        {
+            "$ref": "https://smart-data-models.github.io/data-models/common-schema.json#/definitions/GSMA-Commons"
+        },
+        {
+            "$ref": "https://smart-data-models.github.io/data-models/common-schema.json#/definitions/Location-Commons"
+        },
+        {
+            "properties": {
+                "type": {
+                    "type": "string",
+                    "enum": [
+                        "Certificate"
+                    ],
+                    "description": "Property. NGSI data type. It has to be Certificate"
+                },
+                "state": {
+                    "type": "string",
+                    "format": "uri",
+                    "description": "Relationship. State"
+                }
             }
-          ],
-          "description": "Property. Enum:'falling, raising, steady'. Is the pressure rising or falling? It can be expressed in quantitative terms or qualitative terms"
-        },
-        "dewPoint": {
-          "type": "number",
-          "description": "Property. Model:'https://schema.org/Number'. Units:'Celsius degrees'. The dew point encoded as a number. Observed temperature to which air must be cooled to become saturated with water vapor"
-        },
-        "refDevice": {
-          "anyOf": [
-            {
-              "type": "string",
-              "minLength": 1,
-              "maxLength": 256,
-              "pattern": "^[\\w\\-\\.\\{\\}\\$\\+\\*\\[\\]`|~^@!,:\\\\]+$",
-              "description": "Property. Identifier format of any NGSI entity"
-            },
-            {
-              "type": "string",
-              "format": "uri",
-              "description": "Property. Identifier format of any NGSI entity"
-            }
-          ],
-          "description": "Relationship. Model:'https://schema.org/URL'. A reference to the device(s) which captured this observation"
-        },
-        "streamGauge": {
-          "type": "number",
-          "minimum": 0,
-          "description": "Property. Model:'https://schema.org/Number'. The water level surface elevation observed by Hydrometric measurement sensors, namely a [Stream Gauge](https://en.wikipedia.org/wiki/Stream_gauge) expressed in centimeters. Units:'centimeters'"
-        },
-        "snowHeight": {
-          "type": "number",
-          "minimum": 0,
-          "description": "Property. Model:'https://schema.org/Number'. The snow height observed by generic snow depth measurement sensors, expressed in centimeters. Units:'centimeters'"
-        },
-        "uVIndexMax": {
-          "type": "number",
-          "minimum": 0,
-          "description": "Property. Model:'https://schema.org/Number'. The maximum UV index for the period, based on the World Health Organization's UV Index measure. [http://www.who.int/uv/intersunprogramme/activities/uv_index/en/](http://www.who.int/uv/intersunprogramme/activities/uv_index/en/) the values between 1 and 11 are the valid range for the index. The value 0 is for describing that no signal is detected so no value is stored"
-        },
-        "aqiMajorPollutant": {
-          "type": "string",
-          "description": "Property. Model:'https://schema.org/Text'. Major pollutant in the Air Quality Index (AQI)"
-        },
-        "aqiMajorPollutantForecast": {
-          "type": "string",
-          "description": "Property. Model:'https://schema.org/Text'. Forecasted major air pollutant in the Air Quality Index (AQI) over a certain duration in future"
-        },
-        "airTemperatureForecast": {
-          "type": "number",
-          "description": "Property. Model:'https://schema.org/Number'. Forecasted value of air temperature over a certain duration in future"
-        },
-        "precipitationForecast": {
-          "type": "number",
-          "description": "Property. Model:'https://schema.org/Number'. Forecasted rainfall over a certain duration in future"
-        },
-        "airQualityIndex": {
-          "type": "number",
-          "description": "Property. Model:'https://schema.org/Number'. Air quality index is a number used to report the quality of the air on any given day"
-        },
-        "relativeHumidityForecast": {
-          "type": "number",
-          "description": "Property. Model:'https://schema.org/Number'. Forecasted relative humidity (water vapour in air) over a certain duration in future"
-        },
-        "airQualityIndexForecast": {
-          "type": "number",
-          "description": "Property. Model:'https://schema.org/Number'. Forecasted overall Air Quality Index (AQI) over a certain duration in future"
-        },
-        "airTemperatureTSA": {
-          "type": "object",
-          "description": "Property. Air temperature time series aggregation",
-          "$ref": "https://smart-data-models.github.io/dataModel.Environment/Environment-schema.json#/definitions/TimeSeriesAggregation"
         }
-      }
-    }
-  ],
-  "required": [
-    "id",
-    "type",
-    "dateObserved",
-    "location"
-  ]
+    ],
+    "required": [
+        "id",
+        "type"
+    ],
+    "title": "Certificate + mapped from ERA ontology by Smart Data Models",
+    "description": ""
 }
\ No newline at end of file