Weather Satelites
Weather Satellites: Keith Holland, G3MCD, gave the club a talk
on 25th March about receiving pictures from weather satellites. Weather satellites
fall into two main groups (1) polar orbiting at about 500 miles up (on 137-138MHz)
and (2) geostationary satellites over the equator at about 25000 miles up
(on 1700 MHz). Part of his talk was a demo, and an infrared image was taken
from the American polar orbiting satellite NOAA17 on 137.62MHz as it crossed
Europe at 9.08pm. Keith used a crossed dipole aerial mounted on a pole inside
the clubroom, with an Timestep receiver. He also showed an RX2 receiver. The
RX2 is a home built receiver kit from the Remote Imaging Group costing about
£55. The satellite signals were decoded on a laptop using a freeware program
WXSat. We heard the NOAA 17 satellite and managed to get an infrared picture
of part of Denmark and some of the UK under cloud. The image below is from
a pass of the same satellite on a clear summer evening. A list of pass times
for NOAA17 and websites for free software was given out at the meeting. If
you missed the meeting and would like a copy, send Keith an e-mail at: g3mcd@koholland.plus.com
Keith is a retired engineer and the Deputy Manager for the RSGB responsible
for North London and Herts. He has been a member of the Remote Imaging Group
(RIG) since the mid eighties and he runs a help line for people setting up
weather satellite systems.