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安诺尼AARONIA实时频谱分析仪侦测FHSS跳频信号方向

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#1 2023-01-04 11:25
FHSS,跳频技术 (Frequency-Hopping Spread Spectrum)在同步、且同时的情况下,接受两端以特定型式的窄频载波来传送信号,对于一个非特定的接收机,FHSS所产生的跳动信号对它而言,也只算是脉冲噪声。FHSS所展开的信号可依特别设计来规避噪声或One-to-Many的非重复的频道,并且这些跳频信号必须遵守FCC的要求,使用75个以上的跳频信号、且跳频至下一个频率的最大时间间隔(Dwell Time)为400ms。
以下是关于安诺尼AARONIA实时频谱分析仪侦测FHSS跳频信号方向的相关讨论:1、假如FHSS信号的频率为912-926MHz,间隔时间为200ms,使用安诺尼的Direction Finding测向模块如何解决无法捕捉信号的问题(在声音噪声上显示方向,但在信号上不显示方向)?
A:如果我们要跟踪短脉冲信号,那么就需要选择AARONIA安诺尼Direction Finding测向模块chopper mode选项,该选项可以跟踪µs范围内的信号。

2、天线默认的设置是“chopper mode off”,但“Chopper time”的默认设置是996µs。如果chopper mode off,这意味着什么?此外,如果我们打开chopper mode,则有不同的chopper mode选项(10µs、100µs等),那么这些选项如何与斩波器时间Chopper time对应。还有就是“generic”选项的作用是什么?
最后,IQ Direction Power Spectrum是否必须正确使用此功能?如下图所示:


A:关于这个问题,可以参考下面德国相关解答。此外需要注意:安诺尼IsoLOG DF测向天线的chopper mode必须要使用trigger box。
最后编辑安诺尼_LEE 最后编辑于 2023-01-04 11:29:33
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#2 2023-01-04 11:29

Chopper mode and chopper time in IsoLOG df

Hello aaronia team!

I am using an isolog antenna for df and in it's configuration I found out that I can either use switch time for activating  each sector while chopper mode is "off" or use 10,100 or 1000 micro second chopper time for activating each antenn sector. If I am wrong till here please note me.
My question is that if I am forced to choose 10,100 or 1000 microseconds what is the "chopping time" below the "chopping mode" option in the configurations?
And it would be appreciated to tell me a little about generic mode in the chopping mode option.


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"Chopper Time" only applies when "Chopper Mode" is set to "generic". That way you are not restricted to the predefined switch times available under "Chopper Mode".
There is nothing special about the "generic" mode otherwise.
With "Chopper Mode" set to "off", the antenna is completely controlled by the application, which due to network latency limits how fast you can cycle between sectors and elements (controlled by "Switch Time"). With "Chopper Mode" enabled the antenna will automatically cycle between elements which allows much faster cycle times, but imposes restrictions on associating signals with individual sectors/elements (as it completely relies on timing then), so the direction finding may be less accurate.


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Thanks for clarification.
So if my signal can be detected in chopper mode "off" (I mean if it is "ON" for at least 20 ms) it's better not to use chopper mode to get more accurate Df.
Am I right?


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Chopper mode offers much more measurements so its much more accurate.
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