Checking Receiver Phase Noise

Test Goal

Verify the stability of the STALO by looking at the phase noise of a clutter target.

Background

For proper velocity calculations and for ground clutter rejection, radar's must STALO maintain a stable frequency, and that the transmitted pulse must not contain any amplitude or phase artifacts.

Test Equipment

Ascope utility. See IRIS and RDA Utilities Guide (M211316EN).

Known clutter targets with no weather signal

Test Procedure

1. Configure the radar for normal operation expect pointing at a known clutter target.
2. Run the Ascope utility and configure as follows:
   • 16-bit time series
   • Spectrum not from DSP
   • Spectrum size 256
   • Rectangular window
   • Short pulse width
   • High PRF
   • No clutter filters
3. Select the maximum range and number of bins to get the maximum resolution over the target. For targets < 24 km, use 201 bins, 25 km.
4. Select the range bin of the target.
5. Try minor changes in Az, El, and Range to get the lowest phase noise. The goal is less than 1° within 20 km.
6. Record the Az, El, Range and Phase Noise:

   Az: ______	El:______	Range: ______	Phase Noise:______
   Az: ______	El:______	Range: ______	Phase Noise:______
   Az: ______	El:______	Range: ______	Phase Noise:______
   Az: ______	El:______	Range: ______	Phase Noise:______
   Az: ______	El:______	Range: ______	Phase Noise:______
   Az: ______	El:______	Range: ______	Phase Noise:______

Checklist