🎈 Quick start

This tool draws a Stüve, Emagram, or Skew-T diagram from Windsond S2 radiosonde ascent data. Load your own CSV, or explore the sample flight. Hover the chart for readings at any height — diagram type, altitude unit, and wind display are adjustable just above it. Export, print, or share a link once you're ready.

Confirm Transition Altitude

Below the transition altitude, altitudes are shown in feet (QNH-referenced) instead of Flight Levels — standard aviation practice. This is an estimate based on the launch site's elevation, not a lookup of the actual published airspace boundaries — please check the current AIP for this location and adjust if needed.

Transition altitude: ft

Is the sonde still in ascent?

Do you want to keep polling this CSV file until the sonde flight is completed? The diagram will keep rebuilding itself as new rows are written to the file.

Polling interval: sec

Upload to SondeHub (Amateur)

This sends this flight's ascent telemetry to amateur.sondehub.org, where it becomes publicly visible on their live map. SondeHub's own tools are built for near-real-time tracking; uploading a completed flight after the fact works technically but isn't the typical use case — please make sure that's okay before proceeding. The upload uses SondeHub's published API directly from this page; if your browser or network blocks the request (a real possibility, since this isn't the exact workflow SondeHub was designed for), you'll see an error below instead of a silent failure.

Your callsign / identifier (required by SondeHub):

Payload callsign (shown on the map):

Amateur Radiosonde Telemetry

Radiosonde Sounding Diagram

please load Windsond S2 ascent data … · v1.03.04 (2026-08-04)

· v1.03.04 (2026-08-04)

⤒ Load new CSV (raw_flight_history)

Saved flights (this browser)

⚖ Compare flight

Keyboard shortcuts

PPrint TToggle light/dark EExport CSV LCreate link

Click the time scrubber or the zoom handles, then use ← → (or ↑ ↓) for fine, one-step adjustments.

Print with side panels?

Hodograph, rise speed, Theta-E, and flight path can be included, or left out so the main diagram fills the page instead.

Link (data is encoded directly in the link):

No sounding loaded yet - I am sad, idle and bored ...

Upload a raw_flight_history CSV above, or click the highlighted ▶ Sample data button to load an example ascent.

Flight Statistics

Flight Analytics

Analytical Comments

Graph Variables

DIAGRAM TYPE

ALTITUDE

TA: ft (edit)

SPEED

BARB DENSITY

WIND DATA

THETA-E

CLOUD SHADING FROM

% RH

ZOOM

SCRUB TIME

Hodograph (kt)

Rise speed (m/s)

Theta-E (°C-eq)

Flight path

Map tiles unavailable (offline or blocked by network) — showing flight path only.

x = temperature (°C) · y = (p / 1000 hPa)^0.286, axis inverted (ground at bottom) · dew point via Magnus formula · dry adiabats: straight lines T=θ·y · moist adiabats: pseudoadiabatic integration (Bolton 1980) · one wind barb per isobar level (sonde's GPS ground speed/heading used as a wind proxy, in knots) · only the ascent phase is shown (automatically detected up to the altitude maximum).
This file is a self-contained web application — uploading a CSV locally is enough, no account needed to use it. "Create link": the full dataset is stored via a small shared Cloudflare Worker endpoint, so the link only carries a short reference (works for anyone visiting this page, no login required). If that storage endpoint is unreachable, the button automatically falls back to a self-contained link with the data thinned down and encoded directly in the URL — still shareable, just not full resolution. Reverse-geocoding the launch location and the map's street tiles also need an internet connection; if blocked, coordinates and a schematic flight-path plot are still shown instead.