This site will look much better in a browser that supports web standards, but it is accessible to any browser or Internet device.

Skip Navigation skip menu and banner
University of Wyoming UW Home Wyo Web About UW Apply A-Z Directory Phone/E-mail Search UW

WCR Standard Operating Modes

When installed on the King Air, the radar can be configured to operate with up to 4 antennas(see below). For installation on NCAR C130 there is one dual-antenna configuration available(nadir and down-aft). Typically the radar is operated with maximum range set between 1 and 6 km, minimum range of 75 m, and minimum range gate spacing of 15 m (see examples below).

The radar is also available in a ground mobile platform, "Microwave Atmospheric Remote Sensing Facility" (MARSF). In this configuration it uses a 0.6m cassegrain antenna and a scanning installation that allows 360 deg azimuthal covarage and 180 deg elevation coverage. The ground platform is a 28-foot trailer.

WCR Configurations on the KingAir

Installation:

The King Air WCR installation has 4 antennas in the following configuration.

  • Antenna1: Up/Side pointing antenna with linear single- or dual-polarization(H/V) capability
  • Antenna2: Down (near nadir) pointing antenna with single polarization
  • Antenna3: Side-fore(~35 deg forward from side) pointing antenna with single polarization
  • Antenna4: Down-fore(~30 deg forward from nadir) pointing antenna with single polarization

Modes:

The radar can switch between the antennas on a pulse-by-pulse basis. No polarization capability is available when all 4 antennas are used. For a single antenna use, only Antenna 1 (side/up) allows dual-polarization. All meaningful antenna modes are given below.

  • 1: - Up/Side, Antenna1, singel- or dual-polarization, and single-direction Doppler
  • 2: - Nadir, Antenna2, single-polarization, and single-direction Doppler
  • 3: - Up/Side and Down, Antennas 1 and 2, one polarization, and dual-beam Doppler
  • 4: - Up/Side and Side-slant, Antennas 1 and 3, one polarization, and single- Up and Side Doppler or dual-side Doppler
  • 5: - Down and Down-slant, Antennas 2 and 4, one polarization, and dual-down Doppler
  • 6: - Up/Side, Down and Down slant, Antennas 1,2,4, one polarization, and single Up/Side and dual-down Doppler
  • 7: - Up/Side, Side slant, and Down, Antennas 1,2, and 3, one polarization, single Up,Side-slant and down Doppler or dual-side and down Doppler
  • 8: - Up/Side,Down,Side-slant,Down-slant, Antennas 1,2,3, and 4; Dual-Doppler in two (side and down) planes or Up, Side-slant single-Doppler and dual-down Doppler

Limitations:

1) Antenna 1 can be switched between SIDE and UP during flight while recording. A manual switch repositioning a mirror plate redirecting the antenna beam is used. About 3 sec of data is lost during the switch.

2) If Antenna 1 is installed in a dual-pol config no more than two additional antennas can be installed

Configuration Table:

* H and V are antenna(receiver channel) designation and not polarization. Cross-channel data (HV, VH) is meaningless.
** Up, down, and side are all close to normal w.r.t. the aircraft longitudinal axis. The side slant beam is directed about 35 degrees forward of "side," and the down slant beam is directed about 30 deg forward of "down."(fore) for KingAir, and ~36 deg backward of "down" (aft) for NCAR C130.
***H and V refer to their corresponding polarizations when a WCR beam is pointing horizontally and normal to the aircraft axis.
****The only mode available for NCAR/C130 with the beam channels switched (Beam2: H, Beam4: V).

Radar DSP algorithms

  • Single Antenna/Polarization Mode (SPPMAG)
Transmit:
H or V sequence of 4-pulse bursts for Antenna 1 or single-pol for any of the other 3 antennas
Receive:
H and V backscatter for Antenna 1 or co-pol only for all other antennas
Calculate:
Averaged co-(and cross- for Ant.1)pol returned power magnitude
Averaged pulse-pair phase
Average:
N pulses (min/max N depends on the choice of other parameters)
Transmit:
sequence of H and V combination of 4,6 or 8-pulse bursts
Receive:
co-pol backscatter for each antenna and cross-pol for Antenna1
Calculate:
Averaged co- (and cross- for Ant.1) pol returned power magnitude stored
separately for every pulse in a burst. Averaged pulse-pair phase
for the 3,5 or 7 possible pulse pairs in a burst
Average:
N pulses (min/max N depends on the choice of other parameters)
Example:
If HHVV is the transmitted sequence for Ant.1 there are 4 magnitudes:
HH, VH, HV, VV (XY, X-received, Y-transmitted)
and 3 pulse pairs:
PulsePair 1-2: HH (co-channels only)
PulsePair 2-3: HV (co-channels only)
PulsePair 3-4: VV (co-channels only)
Transmit:
sequence of single-pol pulses for one of the 4 antennas
Receive:
co-pol backscatter
Calculate:
32- or 64-spectral line Doppler spectrum
Average:
N spectra

  • Examples of typical radar parameter sets for antenna installation A, modes 1/2 and different DSP algorithms:

Parameter

Example 1
(SPPMAG)

Example 2
(PPMAG4)

Example 3
(FFT)

Pulse Length

250 ns

250 ns

250 ns

Algorithm

SPPMAG

PPMAG4

FFT

Pulse Sequence (ps)

HHHH

HHVV

VVVV

Pulse Repetion Freq. (prf*)

20,20,20,20
[kHz]

20,5,10,5
[kHz]

20
[kHz]

Range Gates (rg*)

150

100

100

Range Gate Spacing (rgs*)

15 m

30 m

30 m

Range Gate Delay (rgd*)

75 m

75 m

75 m

Averages (av*)

348

84

6

Fftbins (bins)

-

-

64

Fftwindow (window)

-

-

1 (Hanning)

Profiles/sec

40

20

20

Data rate

101 KB/s

116 KB/s

505 KB/s

* These parameters are mutually dependent and of limited choice due to DAQ restrictions.