hi i am working on the processing of radar signals,, i have a constant PRI(pulse repitition interval) radar and i take (say 40)pulses , calculate their difference histogram to identify peaks(in a histogram), from peak i can calculate the incoming pulses' PRI i want to ask if i add a gaussian noise in my incoming radar signal pulses, its difference histogram is spread-out, and the peaks are not obvious, how can i guess the PRI from this histogram or is there any method of correcting the histogram spread-out due to noise ?? thanks in advance umair

# radar's signal processing

Started by ●September 3, 2008

Reply by ●September 3, 20082008-09-03

On Sep 3, 8:10 am, "umair039" <umair...@yahoo.com> wrote:> hi > i am working on the processing of radar signals,, i have a constant > PRI(pulse repitition interval) radar and i take (say 40)pulses , calculate > their difference histogram to identify peaks(in a histogram), from peak i > can calculate the incoming pulses' PRI > > i want to ask if i add a gaussian noise in my incoming radar signal > pulses, its difference histogram is spread-out, and the peaks are not > obvious, > > how can i guess the PRI from this histogram or is there any method of > correcting the histogram spread-out due to noise ?? > > thanks in advance > umairFirst, are you using a matched filter or a moving average filter to increase your SNR? Also, how are you calculating the pulse threshold? Do you have to recognize different PRIs simultaneously (due to multiple radars on same frequency)? Darol Klawetter

Reply by ●September 4, 20082008-09-04

>On Sep 3, 8:10 am, "umair039" <umair...@yahoo.com> wrote: >> hi >> i am working on the processing of radar signals,, i have a constant >> PRI(pulse repitition interval) radar and i take (say 40)pulses ,calculate>> their difference histogram to identify peaks(in a histogram), from peaki>> can calculate the incoming pulses' PRI >> >> i want to ask if i add a gaussian noise in my incoming radar signal >> pulses, its difference histogram is spread-out, and the peaks are not >> obvious, >> >> how can i guess the PRI from this histogram or is there any method of >> correcting the histogram spread-out due to noise ?? >> >> thanks in advance >> umair > > >First, are you using a matched filter or a moving average filter to >increase your SNR? Also, how are you calculating the pulse threshold? >Do you have to recognize different PRIs simultaneously (due to >multiple radars on same frequency)? > >Darol Klawetterdear darol i am not using any filter to increase the SNR, my task is to only detect the PRI whose histogram is spread-out after addition of (10% of PRI) gaussian noise, i have to just make some intelligent observations through the spread-out histogram as what portion of histogram really is indicative of the incoming noisy PRI,(in case of original PRI histogram with no noise the peak's index and envelope in the histogram signifies the desired). the pulse threshold is calculated by the formula: needed_pulses = THRESHOLD * (win_size/(max_index*HistogramResolution)); where , needed_pulses = minimum 70% of pulses THRESHOLD = 0.7 win_size = observation window which has 40 pulses of incoming PRI max_index = peak index in a histogram HistogramResolution = 20; currently i am working on the detection of only single PRI(in noisy analysis) , later i will improve my algo to include more PRIs and process those with noise aswell. refer to US Patent 5583505 for details, (www.patentstorm.us) thanks again and takecare waiting for ur further reply umair

Reply by ●September 4, 20082008-09-04

On 3 Sep, 18:07, Darol Klawetter <darol.klawet...@l-3com.com> wrote:> On Sep 3, 8:10 am, "umair039" <umair...@yahoo.com> wrote: > > > hi > > i am working on the processing of radar signals,, i have a constant > > PRI(pulse repitition interval) radar and i take (say 40)pulses , calculate > > their difference histogram to identify peaks(in a histogram), from peak i > > can calculate the incoming pulses' PRI > > > i want to ask if i add a gaussian noise in my incoming radar signal > > pulses, its difference histogram is spread-out, and the peaks are not > > obvious, > > > how can i guess the PRI from this histogram or is there any method of > > correcting the histogram spread-out due to noise ?? > > > thanks in advance > > umair > > First, are you using a matched filter or a moving average filter to > increase your SNR? Also, how are you calculating the pulse threshold? > Do you have to recognize different PRIs simultaneously (due to > multiple radars on same frequency)? > > Darol KlawetterSounds like he wants to detect all radars on same frequency, where noise has been added by these radars to discriminate them as individual useful radars. Maybe the return ping is less useful at locating than the out ping in such a transport lane due to r2 versus r4. cheers jacko p.s. what do you think he wants?

Reply by ●September 5, 20082008-09-05

On Sep 3, 10:10 pm, "umair039" <umair...@yahoo.com> wrote:> >On Sep 3, 8:10 am, "umair039" <umair...@yahoo.com> wrote: > >> hi > >> i am working on the processing of radar signals,, i have a constant > >> PRI(pulse repitition interval) radar and i take (say 40)pulses , > calculate > >> their difference histogram to identify peaks(in a histogram), from peak > i > >> can calculate the incoming pulses' PRI > > >> i want to ask if i add a gaussian noise in my incoming radar signal > >> pulses, its difference histogram is spread-out, and the peaks are not > >> obvious, > > >> how can i guess the PRI from this histogram or is there any method of > >> correcting the histogram spread-out due to noise ?? > > >> thanks in advance > >> umair > > >First, are you using a matched filter or a moving average filter to > >increase your SNR? Also, how are you calculating the pulse threshold? > >Do you have to recognize different PRIs simultaneously (due to > >multiple radars on same frequency)? > > >Darol Klawetter > > dear darol > i am not using any filter to increase the SNR, my task is to only detect > the PRI whose histogram is spread-out after addition of (10% of PRI) > gaussian noise, i have to just make some intelligent observations through > the spread-out histogram as what portion of histogram really is indicative > of the incoming noisy PRI,(in case of original PRI histogram with no noise > the peak's index and envelope in the histogram signifies the desired). > > the pulse threshold is calculated by the formula: > needed_pulses = THRESHOLD * (win_size/(max_index*HistogramResolution)); > where , needed_pulses = minimum 70% of pulses > THRESHOLD = 0.7 > win_size = observation window which has 40 pulses of incoming PRI > max_index = peak index in a histogram > HistogramResolution = 20; > > currently i am working on the detection of only single PRI(in noisy > analysis) , later i will improve my algo to include more PRIs and process > those with noise aswell. > refer to US Patent 5583505 for details, (www.patentstorm.us) > > thanks again and takecare > waiting for ur further reply > umairIt appears that you're adding a jitter of 10% of the nominal PRI, and the distribution of the jitter within this 10% bounds is gaussian, correct? If so, it seems that you could, with a large enough sampling of pulses, see a gaussian distribution in your histogram and thus you could identify the peak, and thus nominal PRI. What I'm I missing? Darol Klawetter