E
F
G
H
To specify your location, select a Configuration
option (map, database, or manual), plug in the
necessary info, then click Submit. From your new
location-specific homepage, select “All passes of
the ISS” to track the International Space Station
or “Radio amateur satellites” to track a ham radio
repeater satellite (Figure J, following page).
On the Radio Amateur Satellites page, click on
one of the radio satellites you want to track from
the Satellite column (such as AO-Echo, aka AO-51;
SaudiSat 1C, aka SO- 50; or AO- 27), then show its
pass chart by selecting “Passes (all)” above the
globe (Figure K).
The pass chart lists all the satellite passes for the
next few days. Each pass is listed by its times and
locations in polar coordinates, for its start, maximum altitude, and end, with each pass typically
taking about 10 minutes. The start and end points
are defined as when the “bird” appears 10° above
the horizon, and the maximum altitude (in degrees
above the horizon) will vary. The azimuth for each
location is listed in compass points (Figure L).
Make sure your location is listed correctly on the
chart, and pick a pass during which the satellite
will come close to directly overhead. Look for max
altitudes that are 45° or higher — the higher, the
I
better. In the example here, the second pass, on July
17 at 3: 50, looks good since its altitude reaches 75°,
but the first pass, on July 16 at 16: 55, only comes up
to 18°, which is very close to the horizon and difficult
to pick up.
Next, find the frequency to tune in to. Satellite
repeaters work with 2 different frequencies — an
uplink and a downlink. You listen to signals received
via the downlink. (If you wish to transmit, you’ll need
to program in the uplink frequency as well.)
To find a radio satellite’s current frequencies,
you have to refer to the authoritative web page for
each individual satellite. Some references online,
including AMSAT (
amsat.org), aggregate frequency
information for multiple satellites, but these can be
incorrect and you often need to dig deeper.
What you want is a current update or schedule
with uplink and downlink frequencies, and this data
51 Make:
