Author Topic: periodicity of reception of AIS signals  (Read 51897 times)

fkjradio

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periodicity of reception of AIS signals
« on: 27 July, 2013, 08:54:21 am »
hello all
i ask about periodicity  because my vessel number up and down periodically , every 30 minutes.
At Hour + 0 to 30min vessels number decrease, and i have only boat really near.
At Hour + 30 to 60min vessels numbers and distances increase

this is very visible on my AisHub STAT :  http://www.aishub.net/aisGraph.html?rrdname=2338&sname=Brest

When I look at your other stats I do not see this phenomenon, any explanation ?

regards jeje


Peter

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Re: periodicity of reception of AIS signals
« Reply #1 on: 19 August, 2013, 07:51:20 pm »
It is very strange indeed. Please describe what equipment/software are you using?

fkjradio

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Re: periodicity of reception of AIS signals
« Reply #2 on: 30 August, 2013, 12:54:23 am »
Receiver is RTL dongle
Software :  aismon (for 2  audio channel) + ais dispatcher + sdr# or sdr-radio v2
Antenna is colinear 6el home made.

Différents configuration testing :

First was 1 dongle and sdr# i have to choice channel A or B

Now to receive both channel in same time i test:
2 dongle  with 2 sdr#
Or 1 dongle with sdr-radio v2 and 2 VFO
Always 2 x Aismon.

Same up and down result with 3 configurations.


Well i see another station close to me : id 2246
I think he use AIS receiver and he look have also "up and down" but not as marked as mine.