Vaisala RVP900 - Page 5

6.6.5 Adjusting Plot Burst Spectra and AFC................................................... 147
6.6.6 Using AFC Test Mode.................................................................................151
6.6.7 Plotting Example for Pulse Width Definition, Waveform,
and Filters...................................................................................................152
6.6.8 Plotting Example for Range Resolution Ambiguity............................. 154
6.7 Pr — Plot Receiver Waveforms..................................................................... 155
6.7.1 Interpreting Receiver Waveform Plots................................................... 155
6.7.2 Available Subcommands In Pr................................................................158
6.7.3 TTY Information Lines In Pr.................................................................... 159
6.8 Pa — Plot Tx Waveform Ambiguity.............................................................. 160
6.8.1 Interpreting Ambiguity Plots.................................................................. 160
6.8.2 Available Subcommands In Pa................................................................162
6.8.3 TTY Information Lines In Ps....................................................................164
6.8.4 Bench Testing Compressed Waveforms.................................................165
7. Processing Algorithms................................................................................169
7.1 RVP Algorithm Overview............................................................................... 169
7.1.1 Measured Quantities.................................................................................170
7.1.2 IF Signal Conversion Process....................................................................171
7.2 IF Signal Processing.........................................................................................172
7.2.1 FIR (Matched) Filter.................................................................................. 172
7.2.2 RVP900 Receiver Modes..........................................................................174
7.2.3 Automatic Frequency Control (AFC)......................................................176
7.2.4 Burst Pulse Tracking..................................................................................177
7.2.5 Interference Filter......................................................................................178
7.2.6 Large-Signal Linearization........................................................................ 181
7.2.7 Amplitude Correction for Tx Power Fluctuations..................................182
7.3 Time Series Signal Processing........................................................................183
7.3.1 Time Series and Doppler Power Spectrum Example............................184
7.3.2 Frequency Domain Processing- Doppler Power Spectrum.................185
7.3.3 Autocorrelation for Moment Estimations...............................................187
7.3.4 Ray Synchronization on Angle Boundaries........................................... 189
7.3.5 Clutter Filtering Approaches................................................................... 189
7.4 Autocorrelation R(n) Processing...................................................................199
7.4.1 Point Clutter Remover..............................................................................199
7.4.2 Range Averaging and Clutter Microsuppression.................................200
7.4.3
Reflectivity............................................................................................... 200
7.4.4 Velocity..................................................................................................... 203
7.4.5 Spectrum Width Algorithms..................................................................204
7.4.6 Signal Quality Index (SQI threshold).....................................................205
7.4.7 Clutter Correction (CCOR threshold).................................................... 205
7.4.8 Weather Signal Power (SIG Threshold)................................................ 206
7.4.9 (Signal+Noise) to Noise Ratio (LOG Threshold).................................. 207
7.5 Thresholding................................................................................................... 207
7.5.1 Threshold Qualifiers.................................................................................207
7.5.2 Adjusting Threshold Qualifiers...............................................................209
7.5.3 Speckle Filter Processing.........................................................................210
7.6 Reflectivity Calibration................................................................................... 214
7.6.1 Plot Method for Calibration of Io.............................................................214
7.6.2 Single-Point Direct Method for Calibration of I
o
..................................217
7.6.3 Treatment of Losses in Calibration..........................................................218
7.6.4 Determining dBZo.....................................................................................219
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