Hi, Thank you very much. I know how the parameters now. But it seems hard to set the phase(channel_index) zero. Because some time I also want to use the two channel correlator to deal with one antenna's RCP and LCP cross correlation. At this situation I should set the phase(channel_index) zero. Do you know how to set the core's output phase(channel_index) zero?
Best Regards. Oliver Wang -----原始邮件----- 发件人: "Andrew Martens" <[email protected]> 发送时间: 2015年2月20日 星期五 收件人: "Wang Jinqing" <[email protected]> 抄送: "[email protected]" <[email protected]> 主题: Re: Re: [casper] question about finedelay_fstop_prog Hi From what I can see of the block internals; The phase slope generated is in the form phase(channel_index) = slope*channel_index + offset slope = theta_fract offset = theta_fs + samples/fft_fs So setting theta_fract to 0 and theta_fs starts the phase at 0 but the phase will slowly increase (see Fringe_Theat_Cnt1). Regards Andrew On Fri, Feb 20, 2015 at 3:48 PM, Wang Jinqing <[email protected]> wrote: Hi, thank you But I have set the theta_fract zero,this means that the phase changing every 4095 FFT cycles is zero, So the output phase should be stable. But now is not like that. Best Regards. Oliver Wang -----原始邮件----- 发件人: "Andrew Martens" <[email protected]> 发送时间: 2015年2月20日 星期五 收件人: "Wang Jinqing" <[email protected]> 抄送: "[email protected]" <[email protected]> 主题: Re: [casper] question about finedelay_fstop_prog Hi Oliver From what I can see, that port determines how quickly the phase offset applied to all channels is incremented. So your value tells it to increment the phase offset every 4095 cycles. I am not sure if there is some way to turn off fringe-stopping. There is some good documentation at https://casper.berkeley.edu/wiki/Finedelay_fstop_prog which may help. Regards Andrew On Fri, Feb 20, 2015 at 3:06 PM, Wang Jinqing <[email protected]> wrote: Hi, I want to use the core finedelay_fstop_prog to design a FX correlator( two stations ) after FFT as the appendix. I have set theta_fract and theta_fs all zeros, fft_fs 4095. I think in this design the the correlated phase should be constant with time. But when I input a sine wave signal then devides into two channels( as two stations' signal), the correlated phase is changing with time. I have tested the model after I removed the finedelay_fstop_prog core and I found the correlated phase is stable. So I think I may set the finedelay_fstop_prog's input parameters not correct. But how to set the parameters correctlly? Best Regards. Oliver Wang
