CSO's API is built on top of the AWS Lambda (serverless) platform and a PostgreSQL database. The API handles data importation (import), exportation (snapshot), and querying (observations).

The following steps can be followed using either yarn or npm

1. Install necessary packages

cd src
yarn install

2. Create .env.yaml file

touch .env.yaml

3. Add variables to env file. SQL_USERNAME, SQL_PASSWORD, SQL_HOSTNAME, SQL_DATABASE refer to the database credentials. SNOWPILOT_PASSWORD, SNOWPILOT_USERNAMErefer to the credentials for accessing SnowPilot's API.ELEVATION_API_KEY` refers to a Google Maps API key with elevation permissions enabled.

SQL_USERNAME: {INSERT_SQL_USERNAME_HERE}
SQL_PASSWORD: {INSERT_SQL_PASSWORD_HERE}
SQL_HOSTNAME: {INSERT_SQL_HOSTNAME_HERE}
SQL_DATABASE: {INSERT_SQL_DATABASE_HERE}
SNOWPILOT_PASSWORD: {INSERT_SNOWPILOT_PASSWORD_HERE}
SNOWPILOT_USERNAME: {INSERT_SNOWPILOT_USERNAME_HERE}
ELEVATION_API_KEY: {INSERT_ELEVATION_API_KEY_HERE}

4. Run lambda locally

ncc run `path/to/lambda.js`

Ex: ncc run src/import/batch.js

5. Deploy to AWS

yarn run build
yarn run deploy

New provider modules should contain two functions, raw_data(min_date, max_date), which should return a list of observations in raw form, and parse_record(record), which converts a record into the standard record format below:

{
  author_name: String,
  id: String,
  timestamp: Date,
  lat: Number
  long: Number,
  depth: Number,
  source: String
}

Elevation data from the Google Maps API is automatically inserted into the records when processed. To ensure that data from the new provider is being fetched, add the provider to the list of provider modules in import/providers/index.js.

REST endpoint: https://api.communitysnowobs.org/observations

See the Jupyter Notebook CSOobservationsAPI_demo.ipynb for a demonstration of effective use of the observations API in Python.

• bbox: Bounding box to return results from, specified by <west,north,east,south> edges in that order. Takes precedence over region. Longitude ranges from -180° to 180°. Example: -120,45,-110,40. Default: None.
• region: Arbitrary polygon to return results from, specified by <long_1>,<lat_1>_<long_2>,<lat_2>_<long_3>,<lat_3>... Example: -120,45_-120,50_-110,50_-110,45. Default: None.
• startDate: Earliest date to fetch results from. Example: 2018-06-23. Default: 2016-01-01
• endDate: Latest date to fetch results from. Example: 2018-06-23. Default: 2016-01-01
• format: Format to return results from. One of geojson, csv, json. Default: geojson
• limit: Maximum number of results to return. Example: 1000. Default: 100
• page: Page number of results to return. Example: 1. Default: 1.

The observations API returns the following attributes for each observation: id, author, source, timestamp (UTC), depth (meters), elevation (meters), long, lat. Explicit long and lat attributes are ommitted in the GeoJSON response, where the coordinates are encoded as standard point geometries.

Request up to 10 observations between 120°W and 110°W, 40°N and 45°N from Jan 2018 formatted as indicated by the format parameter.

import requests

params = {
  "bbox": "-120,45,-110,40",
  "startDate": "2018-01-01",
  "endDate": "2018-01-31",
  "format": "geojson",
  "limit": 10,
}

response = requests.get("http://api.communitysnowobs.org/observations", params=params)
print(response.content)

data = urlread('https://api.communitysnowobs.org/observations', 'Get', {
  'bbox', '-120,45,-110,40', ...
  'startDate', '2018-01-01', ...
  'endDate', '2018-01-31', ...
  'format', 'csv', ...
  'limit', '10'
});
disp(data)

curl -G https://api.communitysnowobs.org/observations \
  -d bbox=-120,45,-110,40 \
  -d startDate=2018-01-01 \
  -d endDate=2018-01-31 \
  -d format=json \
  -d limit=10