Paul,
Tropospheric bounce sounds like the most plausable explaination. I was
just exercising alternative explaination. Since you brought it up, I
offer offer the SR161 - $189 and SR162 - $439 in our software store
http://www.navsoftware.com/sr161.php if anyone is looking for either of
these AIS receivers.
Paul wrote:
"Queeg" wrote in message
oups.com...
Paul wrote:
I just received a SR162 dual-channel AIS receiver, which I will be using
on
my sailboat -- the old single-channel SR161 will end up at home.
Paul - I am assuming that the SR162 and SR161 have the same range, and
that either would have made the same long distance discovery. Is this
right? Or does the dual channel have a better chance of seeing
something far away?
Do you notice much difference in the speed of target information
acquisition between the two? Is the SR162 noticeably faster? My SR161
picks up targets and shows their speed quickly, but can take 5 or 10
minutes to fill in the name, size, destination, etc.
Gary,
I haven't compared the specs, but I am assuming that the sensitivity is
similar between the two units. I haven't done enough comparison to say for
sure, but the dual-channel unit ought to acquire the info more rapidly --
and that does seem to be the case from my brief experience. I will move my
older single-channel unit to my house (just for fun, and as part of my
development platform).
I want the dual-channel unit on the boat, because my antenna will be mounted
on the stern rail (not as good as on the mast), and I want to acquire the
signals ASAP. I, too, have seen the fast initial acquisition of the dynamic
data, which gets sent often, and the slow (or not at all) acquisition of the
static data, which is sent less frequently. The dynamic data is all you
really need for collision avoidance, but it is nice to get the ship name
(contained in the static data).
I will report back once I get more experience with the system. So far, the
SR162 seems very nice, although the price delta from the single-channel unit
is a bit steeper that I would like.
-Paul