1. Henk Klein Baltink Atmospheric Research Section
BBC2 radar data
Henk Klein Baltink
Atmospheric Research Section

2. CloudNET Workshop Toulouse
Outline
intercomparison 3 radars on , BBC2
intercomparison 3 radars on , BBC1
some issues 35 GHz cloudradar:
power loss
operational modes
cloud mask
20/21 October 2003
CloudNET Workshop Toulouse

3. CloudNET Workshop Toulouse
24th May 2003
3 RADARS:
MIRACLE
(30 m range gate, 5 sec. average profile, ~20 dB offset)
TARA
(30 m range gate, 5 sec average profile)
KNMI RADAR
(90 m range gate, 15 sec combined profile)
period: 7:40 - 9:50 UTC
20/21 October 2003
CloudNET Workshop Toulouse

4. CloudNET Workshop Toulouse
loss of signal due to
raindrops on antenna(?)
artefact of
mode merging
ice clouds (mixed?)
35 GHz Cloudradar data
melting layer
precip
water clouds
insects
rain at surface
20/21 October 2003
CloudNET Workshop Toulouse

5. CloudNET Workshop Toulouse
24th May :40 – 9:50 UTC
35 GHz MIRACLE
TARA CT75
20/21 October 2003
CloudNET Workshop Toulouse

6. CloudNET Workshop Toulouse
7:50 and 8:15
reflectivity
velocity
spectral width
20/21 October 2003
CloudNET Workshop Toulouse

7. CloudNET Workshop Toulouse
Vertical Velocity
Reflectivity
Ice cloud
BBC1
20/21 October 2003
CloudNET Workshop Toulouse

8. CloudNET Workshop Toulouse
research issues:
calibration of radars (BBC2/COST720)
velocity offset 35 GHz?
differences in coded / uncoded mode (dBZ, width)?
20/21 October 2003
CloudNET Workshop Toulouse

9. CloudNET Workshop Toulouse
35 GHz radar issues
power loss
operational modes
cloud mask
20/21 October 2003
CloudNET Workshop Toulouse

10. CloudNET Workshop Toulouse
power loss
20/21 October 2003
CloudNET Workshop Toulouse

11. CloudNET Workshop Toulouse
modes 35 GHz (acquisition cycle)
5000
10000
20 s
BBC1
16 s
After BBC1
acquisition
processing
Height
uncoded
coded
coded X-pol
20/21 October 2003
CloudNET Workshop Toulouse

12. CloudNET Workshop Toulouse
cloud mask
based on Clothiaux et al (5x5 pixels)
too many small clouds are masked
20/21 October 2003
CloudNET Workshop Toulouse

13. CloudNET Workshop Toulouse
to do next months:
analyse BBC1 and BBC2 data
(analysis other datasets with multiple radar?)
improve:
mode merging
cloud mask
insect removal
20/21 October 2003
CloudNET Workshop Toulouse