Notification and download of data from Met Office object services

Timely access to object data at a granular level

This API provides whole-file access to customers who have signed up for a Met Office object service.

Prerequisites:

• Sign up to one or more of the available Met Office object services.
• Receive one or more API keys.
• Receive one or more SNS topic Amazon Resource Names (ARNs) if using an AWS account.

Actions:

1. Set up an endpoint to receive SNS messages: either via AWS SQS or HTTP.

2. During model output periods, receive notifications of newly available files on the endpoint in a format similar to the following:

{
  "Type" : "Notification",
  "MessageId" : "4f3a4169-21d7-55d4-b427-1333c7f84113",
  "TopicArn" : "arn:aws:sns:eu-west-2:123456789012:dataset-id",
  "Message" : "{\"metadata\":{\"forecast_reference_time\":\"2018-02-11T00:00:00Z\",\"forecast_period\":\"0\",\"created_time\":\"2018-02-11T04:30:25Z\",\"name\":\"air_temperature\",\"forecast_period_units\":\"seconds\"},\"url\":\"https://<service-url-supplied-by-Met-Office/id-and-version-information-of-item-requested>\"}",
  "Timestamp" : "2018-02-11T04:41:19.095Z",
  "SignatureVersion" : "1",
  "Signature" : "af0SnkRbIxaZ1P721XkkSqPdCLaIh+/Bri1uonK8n02rnjXQ6fNXJQ4HEbu0bjUB3Wm/CSHAlLc2sVWU5aFFCYABr2UBQfsrutj07dR2OmcF6WX/MHaXodWApBFrXemqpOLJ6e+KRzfGfr+rKczlpLwc9d4CQgPhA5a1eVuKlKWhoLJNuwdxcjA5FhXT/ABx3pmd+GRJ6Zk5uh/2xxV7Kt+TZ7oom/mKIOGU0YV35ki3R+t52aKEXZ43m5J/6LF8G/o1pXeMl9BJWtgdtHA9luLfN1ryNs4TmkSQxFuWXrrHTAL2iYSyxzNKB+a0gg2DfLqS9shsxAqD2HWH4/spyg==",
  "SigningCertURL" : "https://sns.eu-west-2.amazonaws.com/SimpleNotificationService-433026a4050d206028891664da859041.pem",
  "UnsubscribeURL" : "https://sns.eu-west-2.amazonaws.com/?Action=Unsubscribe&SubscriptionArn=arn:aws:sns:eu-west-2:123456789012:dataset-id:bb3b1a84-728a-452a-807f-e92bd3b7d285"
}

Where the "message" value returned will be similar to the following example:

Global Model (Air Temperature):

{
   "metadata":{
   "forecast_reference_time":"2018-02-11T00:00:00Z",
   "forecast_period":"0",
   "created_time":"2018-02-11T04:30:25Z",
   "name":"air_temperature",
   "forecast_period_units":"seconds",
   },
   "url":"https://<service-url-supplied-by-Met-Office/id-and-version-information-of-item-requested>"
}

3. Decide by examining the metadata section in each notification which items you would like to download.

4. Using the url in the notification and the API key (see Prerequisites) as a header called "x-api-key" request the object for download.

5. Receive the requested object as a file download.