SWL – Weather Fax Images

Every wonder what other beeping and buzzing sound off the ham bands are.  Or do you wonder how ships at sea get weather reports.  Well the Nation Weather Service still transmit fax weather maps out on the HF bands.  They have stations in Boston, New Orleans, Pt Reyes California, and Kodiak Alaska they transmit 24/7 on assign frequencies that you can find in this document. So how do you decode and view an fax image on your computer you use the good old FLdigi program the same one you use for decoding RTTY and PSK31 data.  From the OpMode menu item you select WEFAX and the the particular mode is called WEFAX576.  It does take about 10 minutes to receive an full fax image but once set up FLdigi will do all the work. Then just tune to the frequencies listed in the document for example 8.5039 Mhz for New Orleans  and center the tone so that they are around 1500 Hz in the FLdigi waterfall this will then let you set up your filtering to cut out adjacent noise on the the frequency.

If your image starts to look like it slide to the right or left you can adjust the “SLANT” to get the image vertical. You can also use “ALIGN” to center the image on your display. It does take about 10 minutes to receive the whole fax image but FLdigi will store the image automatically at the end of the broadcast. Now different station transmit different images. I have notice that Pt Reyes show the Pacific ocean images and New Orleans show the southern Atlantic image.


Additional Weather Fax Information:

Satellite Images via Fax: {Poor image due to loosing sync was stitched together}

Click on Image for full size view

53520cookie-checkSWL – Weather Fax Images