User Guide

This guide is split into two parts. Part 1 covers the step-by-step interface instructions for each page. Part 2 is a technical reference for expert users covering the data source, processing pipeline, and DLR classification methodology.

Part 1 — How to Use the Application 

Dashboard 

The Dashboard is your starting point for registering line segments and retrieving weather forecasts for them.

Task 1 — Register a New Span

Prepare a CSV file with your pylon or mast coordinates (see CSV File Format).
Click Upload on the Dashboard.
Select your file in the dialog and confirm the upload.
Your span appears on the map and is immediately available for forecast requests.

Task 2 — Request a Forecast

Select a span from the span list on the Dashboard.
Click Request Forecast.
A loading indicator appears while data is fetched and processed.
Charts update with forecast values for all coordinate points in your span, covering a 0–23 hour window from the latest model run.

Task 3 — Read the Results

Each chart shows a forecast parameter (wind, temperature, humidity, etc.) plotted over time.
Hover over chart points to see exact values at a specific hour.
For a continental overview of DLR conditions, navigate to the Severity Map page.

Spans Page 

A span is a named transmission line segment defined by an ordered set of pylon/mast coordinate pairs. The Spans page is the central place to review and manage all spans registered in your account.

Task 1 — View Your Spans

Click Spans in the navigation bar.
Your saved spans appear in a list with their names and coordinate counts.
Click any span to expand its details and inspect the individual coordinate points.

Task 2 — Manage a Span

Delete: Select a span and click the delete action.
Reuse for forecasts: Return to the Dashboard and select the span from the span list to request a new forecast.

Severity Map Page 

The Severity Map provides a continental overview of DLR conditions across Europe based on the latest forecast.

Click Severity Map in the navigation bar.
Use the forecast hour slider (0–23 h) to step through the forecast window.
Each grid cell is colour-coded by DLR severity class (1 = Very Favorable to 6 = Super-Critical).
Refer to the on-screen legend to interpret the colour scale.

Part 2 — Technical Reference 

Data Source 

All forecast data originates from the Destination Earth (Extremes) Digital Twin (DE_330 project), accessed via the Polytope RESTful API using the earthkit-data library. The service polls for new data on an hourly automated schedule.

Data covers Western Europe on a structured geographic grid. The following meteorological variables are extracted at each grid node and interpolated to user-supplied coordinates:

10m wind (U and V components) — used for DLR severity and exposed as wind_u / wind_v forecast parameters.
2m temperature — exposed as the temperature forecast parameter.
Relative humidity — exposed as the humidity forecast parameter.
Solar radiation — used internally as a Joule-heating input to the DLR severity algorithm; not exposed as a selectable forecast parameter.
Precipitation — used as an evaporative-cooling input to DLR severity and exposed as the precipitation forecast parameter.

CSV File Format 

Span coordinates must be supplied as a UTF-8 comma-delimited CSV file with a header row. Each row represents one pylon or mast location, ordered along the line segment.

Column	Type	Description	Example
`lat`	float	WGS 84 latitude in decimal degrees	`50.8503`
`lon`	float	WGS 84 longitude in decimal degrees	`4.3517`

Additional columns are permitted and will be ignored by the parser. Coordinates must lie within the Western European coverage area of the Destination Earth Extremes Digital Twin dataset.

Forecast Processing Pipeline 

Data retrieval — The backend connects to the Polytope API and fetches the latest DestinE Extremes Digital Twin GRIB fields for Western Europe on an hourly schedule.
Coordinate interpolation — User-supplied pylon coordinates rarely coincide with exact model grid nodes. A KD-tree nearest-neighbor algorithm finds the closest grid point for each coordinate, ensuring spatially consistent extraction along the full line corridor.
Multi-tier caching — Fetched GRIB fields are stored in a file/metadata/memory cache. Subsequent requests for the same forecast window are served from cache, significantly reducing latency and load on the Destination Earth platform.
Output — Time series of meteorological parameters are returned per coordinate point, covering a 0–23 hour horizon from the latest model run.

DLR Severity Methodology 

See DLR Severity Map for the full description of the CIGRE-based composite algorithm, the BASE/EXTENDED severity indices, and the five-class classification scale.