User Tools

Site Tools


difx:ivs2016extras

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
difx:ivs2016extras [2016/03/10 03:27]
walterbrisken
difx:ivs2016extras [2016/03/11 20:43] (current)
walterbrisken
Line 7: Line 7:
 The utility m5spec can read baseband data and generate spectra. ​ The program and output text file containing the spectrum is documented in {{DiFXUserGuide.pdf|Reference Manual}} sections 5.50.  This program works on many varieties of VLBA baseband data (including the Mark5B data in the first dataset), but does not work on VDIF data with multiple threads (e.g., from the second dataset). ​ The dataformat parameter appropriate for dataset 1 data is Mark5B-2048-16-2,​ and a complete command to generate spectra with 500 spectral points per baseband channel is: The utility m5spec can read baseband data and generate spectra. ​ The program and output text file containing the spectrum is documented in {{DiFXUserGuide.pdf|Reference Manual}} sections 5.50.  This program works on many varieties of VLBA baseband data (including the Mark5B data in the first dataset), but does not work on VDIF data with multiple threads (e.g., from the second dataset). ​ The dataformat parameter appropriate for dataset 1 data is Mark5B-2048-16-2,​ and a complete command to generate spectra with 500 spectral points per baseband channel is:
  
-''​m5spec /XXX/YYY.ZZZ ​500 2000 spec.out''​+''​m5spec /home/avntrainee/​difx_data/​n6043/​NRAO+301_0540_N6043_PT_No0008 ​ Mark5B-2048-16-2 ​500 2000 spec.out''​
  
 Here the number 2000 is the number of FFT frames to process. ​ Increasing that number will lead to more averaging and a spectrum with higher signal to noise. ​ It might be instructive to change the values of the two numbers (number of spectral points and number of FFTs to process) to get a feel for how these parameters change the output. Here the number 2000 is the number of FFT frames to process. ​ Increasing that number will lead to more averaging and a spectrum with higher signal to noise. ​ It might be instructive to change the values of the two numbers (number of spectral points and number of FFTs to process) to get a feel for how these parameters change the output.
difx/ivs2016extras.txt · Last modified: 2016/03/11 20:43 by walterbrisken