3. Developers Guide

For seamless integration work the WIS API is documented using Swagger accessible through the link below.

Weather Information Service (WIS) - Swagger UIwis.unisphere.io

3.1 Available Endpoints

The WIS contain the following endpoints that deliver information based on the following categories:

1. Now – current weather values - how is the weather right now.

2. Forecast – weather data at a certain point in time in future (up to 24 hours).

3. Metar_nearby – decoded METAR information and raw METAR of nearby station of requested location.

4. User & Subscription Information

3.2 Parameter Names in for NOW and FORECAST Endpoints

3.3 Parameter Names METAR_NEARBY Endpoint

METAR information according ICAO Annex 3, July 2010.

(https://www.icao.int/airnavigation/IMP/Documents/Annex%203%20-%2075.pdf)

3.4 Data Sources

If the API request is set to <auto> or not set at all the API response will return weather information from the best source available, the requested location (latitude/longitude).

Weather information from authoritative sources

Current implementation stage uses the WAWFOR GLOBAL or WAWFOR EU dataset provided by the German Weather Service (DWD). https://www.dwd.de/EN/ourservices/aviation_wawfor/wawfor_node.html

If the requested location is within the WAWFOR EU boundaries it will return the corresponding values. Else will respond in the WAWFOR global dataset.

WAWFOR EU covers the following boundary box: Europe 23.5° W to 62.5° E / 29.5° N to 70.5° N

WAWFOR GLO covers the following extensions: Global -180° to +180 / 80.0° N to 80.0° S

METAR Information

METAR information from nearby airports / weather observation stations will be provided as string through the API. It is recommended that METAR information always be displayed to the end user to ensure compliance due to the missing parameters of some authoritative weather sources.

As a minimum (specified in paragraph 2. / EASA 2021/664 Article 12 Weather Information Service) the WIS will provide:

1. wind direction measured clockwise through the true north and speed in metres per second, including gusts;

2. the height of the lowest broken or overcast layer in hundreds of feet above ground level;

3. visibility in metres and kilometres;

4. temperature and dew point;

5. indicators of convective activity and precipitation;

6. the location and time of the observation, or the valid times and locations of the forecast;

• (a) the location of the observation or forecast using:

  • (1) ICAO designator, where available; or

  • (2) the location expressed in WGS-84 coordinate.

• (b) the validity of the observation or forecast by specifying:

  • (1) WGS-84 position or WGS-84 area of validity; and

  • (2) the time of the observation and/or the validity of the forecast in UTC time

1. appropriate QNH with geographical location of its applicability.

2. Other sources are named within the parameter table under chapter 3.2.

Be aware that the provided METAR information can be multiple kilometres away from the requested location and therefore not sufficiently reflect the conditions on the requested location.

3.5 Performance

3.5.1 Software Interfaces

The standards for communication interfaces with clients are:

1. REST API

2. Secured communication is achieved using the HTTPS protocol

3.5.2 Security Precautions

1. Authentication is managed through a dedicated API key for your organization (username & password). When subscribing to the WIS of Unisphere the API key will be shared through a secure channel.

3.5.3 Rate Limit

1. The initial rate limit of the WIS API is 1000 requests per minute for each endpoint

2. API response when reaching the rate limit: Response 429 - too many requests

3.5.4 Parallel Requests

1. The maximum number of parallel requests of the WIS API is 10 per minute and endpoint except not stated differently in the subscription.