Worldwide Archive of Low-frequency Data and Observations

Hello and welcome to WALDO World! Here we are building the world’s largest repository of publicly available ELF/VLF/LF radio data, which is used to study the physics of lightning, the ionosphere, and the magnetosphere.

The mission of WALDO World is to collect, curate and deliver ELF/VLF/LF radio data for scientific use for open public use. WALDO World spin out of a joint effort between Georgia Tech and CU-Denver, using data collected by Stanford University from the 1970s until 2016, and then continued collection by both Georgia Tech and CU-Denver starting in 2014.

Read about us in AGU’s EOS magazine!

In order to download the data, just create an account and verify your email. The account is free, no restrictions or permissions needed at any time. As soon as you are signed in, it will unlock the download buttons in the website. A reminder that if anyone needs more direct or wider access, please contact us and we can help arrange it.

These data do/will include many valuable recordings, amongst them

Our hope is for the broader community to think of new ways to analyze these datasets that have not been previously considered.

With the menus above, you can directly access all the raw data, including (1) Broadband VLF data, (2) Broadband LF data, (3) Narrowband data. Quick-look summary plots are available if desired. Check out the “What’s available?” to see maps calendars, and charts showing what data is currently on WALDO. You can navigate a large folder directly and download files either one at a time, or a whole folder at a time.

However, if you have interest in larger-scale access or are having trouble downloading the data fast enough, let us know, there are ways to arrange more direct access via a mounted Google Drive. All we need is a Gmail address to share it with, and for you to download the “Drive” app from Google.

We’ve also released some tools to help anyone use the data. The format page goes over the file format and the naming convention of the files. The scripts page contains Matlab-ready scripts to analyze the data in various way, and we note that the format is simple enough that utilities in any language or platform can easily be written to read the data files. The usage page details restrictions on the data usage (spoiler: there aren’t many). And finally, we have a page with some occassional updates as we add data and features to this website.

Right now we are working on transferring everything, but it will take some time since we’re talking about 1000 TB much of which is on DVDs. However, if there a specific dataset you know was recorded that is not yet up at WALDO that you would like to see, please contact us, morris.cohen@waldo.world and mark.golkowski@waldo.world. We can let you know if it still exists, and/or prioritize it if you have a specific interest.

Here is a PARTIAL map of some of the sites that will be on WALDO. To keep the map from being too busy, we skipped some (for now), and compressed some “clusters” of receivers into one. To get a better idea of what sites are available, look in the “What’s Available” page, and find the “Availability Maps” which show precisely what sites are available for each day. Or, click on the “World map” link in the above menu, and you can find out how much data is available for each site that is currently on WALDO. We’ll be updating this Google map periodically.

Partial map of VLF sites with data on or in the queue for WALDO

And finally, here’s a picture taken from a VLF antenna setup in central Alaska, just to give you an appreciation of the time, thought, and yes, funding, to collect all this data in the first place.

VLF antenna in Alaska