US Naval Academy Boats

Bob Bruninga, WB4APR, US Naval Academy Satellite Lab, Annapolis, MD

The USNA Satellite lab works with Prodev and SCRF to maintain communications with the boats on summer cruise. Since 1991, we have experimented with a variety of digital comm methods including HF, FLTSAT and APRS. At the bottom of this page you will find a replay of previous years experience.

This year we hope to use a new digital mode that is very robust and will offer reliable communications way down into the noise. It is called PSK-31 and a screen shot is shown below. The real advantage of this system is that it requies NO specialized hardware and simply runs on any modern PC with a buiilt-in sound card. Thus, it is as trasportable from boat to boat as a laptop. The biggest difference is that PSK-31 is conversational and allows back-and-forth dialog instead of just Email type forwarding.

Look for a description at the bottom of this image.

First notice the waterfall at the bottom of the display. This shows you what traffic the sound card is hearing. You may click on up to 3 traffic streams and each will be displayed in one of the 3 receive windows at the top of the screen. What you see here are just two HAM radio conversations I picked up while testing. Your one-line transmit window is next though you can type as much or as long as you want. Also, notice the MACROS where you can pre-load your reports and then send them with a simple click of the mouse. All of this can be logged to file.

Operationally, we will probably ask SATFAC, RCROWN, PRODEV, MESHOP and SCRF OPS to transmit down at around 800 HZ. The YP's may use 1000 to 1400 Hz and the CSTS boats may use say 1600 to 1900 Hz. This is so that the human ear can reasonably detect who is transmitting and know whether to go look at his PC or not.

This was a LIVE plot of the current positions of the US Naval Academy boats on summer cruise. There are 4 three week cruise blocks of up to 30 boats underway during the summer. Now it is just a REPLAY of a previous cruise. Be sure to PAGE-UP to see them go to Halifix. For a replay of one of the 3 week cruises in 1993, click here. The time shown is EDT. Messages, and Status are restricted information and are not shown here.

Also we have a special satellite tracker on FROLIC and more detailed charts.

Please either zoom this map with the commands below, or choose another detailed map from the MAP button below. Hit REFRESH each time you view this site to get the current information which is updated every 10 minutes. Also you can check out a photo of our HF station. We hope to use Satellite links for this data, but also have a backup link on a Navy HF frequency at 300 baud.

javAPRS Commands (Case Insensitive)
U or D
zooms up/down (you may also use PGup/dn)
CTRL or ALT-click
Centers or Zooms map on clicked location
Arrow keys
scrolls map

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The Naval Academy is a registered user of APRS and WinAPRS. The purpose of this web page is to show several applications currently in use at this site and should not be considered as an advertisement or an endorsement of any commercial product.

WA8LMF Mirror of WB4APR Website - 21 July 2008