The blog of a dedicated radio amateur and electronics enthusiast

"Having fun on the air and in the workshop - communicating and creating"
Showing posts with label WEFAX. Show all posts
Showing posts with label WEFAX. Show all posts

20 April 2010

Iceland's volcanic plume



The plume of volcanic ash belching from the Eyjafjallajoekull volcano, ( 1666m ), in the Katla range is visible from space. It can just be seen on an image I received yesterday, 19th April at 1215gmt, from the NOAA 19 weather satellite on 137.10MHz.
At first I had almost overlooked it, believing, because of the enormous publicity the eruption had attracted, that from the satellite's viewpoint most of western Europe would be hidden from view under the ash cloud. A further series of images captured today from NOAA 15, 18 & 19 confirm the continued presence of the plume, but show it to be diminishing.
I shall be following the progress of the ash plume/cloud from space and post additional pictures if they are more distinctive.
Iceland is at the limit of my range from here for clear satellite reception; the satellite being only just above my horizon as Iceland comes into view !

17 April 2010

Full earth disc


Previously posted weather satellite imagery has been from satellites in low earth orbit as they pass over above my horizon for upto 15mins every 100mins or so. For full earth disc pictures I had to receive the signals from satellites much further away in the geostationary orbit; in particular satellite Meteosat 7 at 0 deg. E. Using an 80cm satellite tv dish pointing in that direction, I had no problem receiving the analogue WEFAX imagery on 1691MHz. The last time was in 2002; it doesn't seem so, but I checked. That's a long time ago. How time flies !
Recently, I have been occasionally listening for Meteosat 7's transmissions again; but heard nothing. Has the satellite re-entered, or been parked into a graveyard orbit, I wondered. No, instead it has been moved to above the Indian Ocean.
More importantly, the analogue service ceased anyway probably early in 2004. I can't receive the new higher resolution digital service from Meteosat 9, Meteosat 7's replacement at 0 deg. E, without spending some money on equipment. I might not bother.
So, if in the future I don't receive any more full earth disc pics, I have posted one from my archive from 2002, and we just have to imagine the quality and resolution of the digital pics nowadays; or use the web, but that would be too easy.

16 April 2010

Sat pic gallery





Today's images in the visible light band which I received "off-air" from the US National Oceanographic and Atmospheric Administration, ( NOAA ), low earth orbiting weather satellites, NOAA18 & NOAA19, automatic picture transmission, ( APT ), weather facsimilie, ( WEFAX ), service.

From top to bottom:-
NOAA19, 1104gmt, downlink 137.10MHz
NOAA18, 1141gmt, downlink 137.9125MHz
NOAA19, 1246gmt, downlink 137.10MHz
NOAA18, 1323gmt, downlink 137.9125MHz

There is still some sea-ice to be seen at the northern end of the Gulf of Bothnia.
If you look carefully you may see a red cross which gives away the position of my ground station.

15 April 2010

The changing seasons


It is interesting to follow the seasonal changes on earth from the images which I receive directly from weather satellites. The last time on 26th January, ( see post ), showed Europe from Germany eastwards under ice and snow. The images which I captured today tell a very different story.
The infra-red image I have chosen to post here was derived from the heat detected by the infra-red sensor onboard satellite NOAA18, and transmitted on 137.9125MHz at 1151gmt. Darker shades, ( black, brown, green ), represent warmer areas than lighter shades, ( blue, white ). Many Baltic countries had a fine, warm day today. I was outdoors making the most of it !