From be08176f4fe6ad93ec37b2f087f66048511a8e38 Mon Sep 17 00:00:00 2001 From: krakenrf <78108016+krakenrf@users.noreply.github.com> Date: Sat, 5 Nov 2022 20:06:11 +1300 Subject: Updated 08. Passive Radar (markdown) --- 08.-Passive-Radar.md | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/08.-Passive-Radar.md b/08.-Passive-Radar.md index 0a1b786..7204b88 100644 --- a/08.-Passive-Radar.md +++ b/08.-Passive-Radar.md @@ -70,16 +70,12 @@ For passive radar the data block length is an important parameter. Longer data b Another expense is that fast moving objects could spread their energy out over multiple range-doppler cells if the data block length is too long. -We have included three preconfigured DAQ files that can be used which set optimized data block lengths. They are `pr_2ch_2pow20`, `pr_2ch_2pow21` and `pr_2ch_2pow22`. The latter files have longer data block lengths, but update the display slower. +We have included a preconfigured DAQ file that can be used with an optimized data block length. It is titled `pr_2ch_2pow16`. The optimal preconfig file will depend on the specific passive radar implementation and target type. So we recommend experimenting with each of the three preconfig files. ## Passive Radar Bandwidth Settings Guide -The larger the signal bandwidth the more resolution we can obtain from passive radar. The maximum sample rate/bandwidth that the KrakenSDR is capable of operating stably at is 2.4 MHz. - -If you are using wideband illuminators such as HDTV or 4/5G signals, you want to keep the bandwidth at the maximum of 2.4 MHz. This is the default as set in the pr_ preconfig files. - -If you are using DAB (or other more narrow illuminators), note that this only has a bandwidth of about 1.5 MHz. Therefore you will obtain better results if you adjust your bandwidth to match as you don't want to receive the noise floor along the sides of the illuminator. From a base of any pr_ preconfiguration, under the DAQ reconfiguration settings, change the sample rate to 1.4 MHz. And then hit the "Reconfigure & Restart DAQ chain" button. This may take 1-2 minutes before the software has restarted. +The larger the signal bandwidth the more resolution we can obtain from passive radar. Note that the KrakenSDR is restricted to 125 kHz of bandwidth. # Range-Doppler Units The range-doppler graph displays bistatic range and bistatic speed. The axes are currently described in CELLS. In order to convert cells to meters or m/s use the following formulas: -- cgit v1.2.3