More description for selection of sweep types

[Zhihao Tan]

I understand that there are four sweep types. Three of them can be used for ranging (Ramp, Triangle & automatic triangle). The description is clearly explained in the manual page 17 & 18.

I would like to know how to choose the sweep type.

1) Between Ramp & Triangle
Ramp is the most straight forward. Any advantage for the triangle sweep type?

2) Between Automatic Triangle & [Normal] Triangle
Can we alter the sampling frequency of the ADC? If we cannot make the sampling period to be a multiple of the pulse duration, then it is not possible to make use of the data of subsequent pulses. Hence, it is not useful to sample more than one pulse at one go. The only advantage to use 'automatic' is that the user can hear some sounds from the speaker. Am I right?

[RDK Support]

Hi Zhihao Tan, 

 

1) The advantage to using the triangle sweep type is that is allows you to make distance AND doppler measurements.  This is possible due to the up-ramp and down-ramp of the triangle sweep.  Only distance can be measured when using the ramp sweep type. 

2) The sampling frequency can not be altered. However, it can be useful to sample more then once pulse at one go.  An example would be if you are trying to measure the distance of a moving object.  Sampling more then one pulse at a time will allow you to collect more data faster than sampling one pulse at a time.  You are correct that automatic allows you to hear some of the beat signal. 

A good description of Ramp (sawtooth) & Triangle sweeps can be found hear: http://www.radartutorial.eu/02.basics/rp07.en.html . In the Modulation pattern section.