NOAA GMD/OZWV Software Downloads

These software packages were developed by the NOAA Ozone and Water Vapor Group to assist with weather balloon launch planning, data collection/processing, and instrument setup. They are written for Windows (XP/Vista/7/8/10) and require the .NET Framework 4.0 or higher (typically already installed on modern computers). Contact Information:


Disclaimer: The availability of these tools to the general public does not condone attempts to recover balloon payloads that land on private property, government property, or hazardous locations. Predicted trajectories and landing zones are only approximate, therefore active tracking is required to accurately locate launched payloads.

Balloon Prediction

This program forecasts weather balloon trajectories and landing locations, showing the resulting path on a map. Use this to help select safe launch days, avoiding airports, city centers, and other hazardous landing zones (though accurate results are not guaranteed).

  • Calculates weather balloon trajectories/paths and landing locations
  • Uses NOAA GFS model wind data, or NWS radiosonde soundings as input
  • Custom burst/turn altitude, launch locations, dates/times, and time zones
  • Adjustable rise rate tables for different balloons/payloads
  • Detailed mapping, selectable map sources
  • Google Earth KML output file for 3D trajectory viewing

SkySonde Client/Server

A pair of programs for collecting and displaying Intermet iMet-1-RSB radiosonde data telemetry in real-time during a weather balloon flight, along with the NOAA Frostpoint Hygrometer (FPH), EN-SCI/DMT ECC Ozonesonde, and several other instruments.

  • Parses, displays, and stores wireless data from the iMet-1 radiosonde
  • Support for the NOAA FPH and ECC Ozonesonde is built in
  • Extra instrument plugins included for the ETH COBALD, Anasphere SLWC, MetOne OPC, and NOAA POPS (contact Allen Jordan to add more)
  • Audio input data from a receiver can be demodulated directly without a physical modem
  • Client/Server architecture. Can be run on the same computer or across a network (a server computer attached to the receiver, one or more client computers displaying and saving the data)

XDATA Radiosonde Protocol

The XDATA protocol was invented by Jim Wendell ( for connecting external instruments to a radiosonde for wireless data transmission to a ground station. It is currently implemented in Intermet iMet-1-RSB radiosondes, and partially in Vaisala RS41 radiosondes. The documents below describe both the XDATA protocol for instrument to radiosonde communications, and the received data protocol for radiosonde to antenna/receiver communications.

  • Attach custom instruments to a radiosonde for wireless transmission, using only a standard UART module
  • Open protocol implemented on several radiosondes and used by multiple prominent weather balloon instruments
  • The received data protocol allows for writing custom telemetry programs similar to SkySonde

SkySonde Client Plugin System Documentation

SkySonde Client supports plugins for parsing and storing data from other XDATA instruments attached to an iMet radiosonde. Instructions for writing a custom plugin are provided below, along with source code for an example plugin (written in C# using Visual Studio 2013).

  • Make custom XDATA instruments that transmit through iMet radiosondes, and collect the data in SkySonde Client using a custom plugin
  • Customize the metadata collection and real-time data display
  • Output any data fields and calculations, will be matched with current radiosonde PTU/GPS measurements on the same CSV file row