Other Parts Discussed in Thread: AWR1443
Hi,
we are using awr1443 boost to validate the velocity of moving objects .
Below is my profile configuration:
% ***************************************************************
% Created for SDK ver:01.01
% Created using Visualizer ver:1.1.0.1
% Frequency:77
% Platform:xWR14xx
% Scene Classifier:best_range
% Azimuth Resolution(deg):15
% Range Resolution(m):0.244
% Maximum unambiguous Range(m):50
% Maximum Radial Velocity(m/s):1
% Radial velocity resolution(m/s):0.13
% Frame Duration(msec):100
% Range Detection Threshold (dB):15
% Range Peak Grouping:enabled
% Doppler Peak Grouping:enabled
% Static clutter removal:disabled
% ***************************************************************
sensorStop
flushCfg
dfeDataOutputMode 1
channelCfg 15 5 0
adcCfg 2 1
adcbufCfg 0 1 0 1
profileCfg 0 77 465 7 21.85 0 0 44.4 1 256 18500 0 0 30
chirpCfg 0 0 0 0 0 0 0 1
chirpCfg 1 1 0 0 0 0 0 4
frameCfg 0 1 16 0 100 1 0
guiMonitor 1 0 0 0 0 0
cfarCfg 0 2 8 4 3 0 1280
peakGrouping 1 1 1 1 229
multiObjBeamForming 1 0.5
clutterRemoval 0
calibDcRangeSig 0 -5 8 256
compRangeBiasAndRxChanPhase 0.0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0
measureRangeBiasAndRxChanPhase 0 1.5 0.2
sensorStart
Doppler resolution(dopplerResolutionMps) formulas from demovisualizer script:
Dopplerresolutionmps = 3e8 / (2*P.profileCfg[profileCfgIdx].startFreq*1e9 *
(P.profileCfg[profileCfgIdx].idleTime + P.profileCfg[profileCfgIdx].rampEndTime) *
1e-6 * P.dataPath[idx].numChirpsPerFrame);
numChirpsPerFrame = (P.frameCfg.chirpEndIdx -
P.frameCfg.chirpStartIdx + 1) *
P.frameCfg.numLoops;
If we apply this formula for above configuration:
numChirpsPerFrame = (1 - 0 + 1) *16;
=32;
Dopplerresolutionmps = 3e8/(2*77*1e9*(465+21.85)*1e-6*32)
= 0.125041847
this is one of the object's data from uart log:
0x05;0x00; - range index
0xF8;0xFF - doppler index
0x72;0x01; - peak val;
0x22;0x00; - x range
0x99;0x00; - y range
0x00;0x00 - z range
Dopplerindex = 248+(255*256) //from demovisualizer script
= 65528
if(65528 > 32767)
{ Dopplerindex = 65528-65536;}
di = -8
so Doppler = di * Dopplerresolutionmps //conversion of doppler index to doppler(meters/sec)
= -8* 0.125041847
= -1.00033 meters per sec
so velocity of object is = -1.00033 * 3.6
= -3.601188 kilometers per hour moving towards radar.
a) Is our understanding correct here ,In number of Doppler bins,doppler resolutionmps,velocity of object calculations.
(or) any misinterpretation or wrong calculation?
b) Above formulas are valid in all scenarios,if we are not changing anything in profile configuration?
Thanks,
P Tulasi Krishna.
