ESA-JAXA Pre-Launch EarthCARE
Science and Validation Workshop
13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

FRM4Radar –Cloud Profiling for Satellite Validation
Lukas Pfitzenmaier1, Annika Daehne1, Pavlos Kollias1,2, Salomon Eliasson3, Anke Thoss3, Leonardo
Porcacchia3, Anca Nemuc4, Razvan Pirloaga4, Bogdan Antonescu4, Doina Nicolae4, Ewan O’Connor5, Jonas von
Bismarck6, Timon Hummel71) University of Cologne, Germany2) Stony Brook University, NY, USA
3) SMHI, Sweden 4) INOE, Romania

5) Finish Meteorological Institute, Finland6) ESA / ESTEC

7) ESA / ESRIN

Objectives of the FRM4Radar Project• Create the foundation for Fiducial Reference Measurements (FMR) for theEarthCARE Cloud Profiling Radar (CPR)• The role of the FMR’s is to deliver confidence to user community in the CPR
products by means of ground-based observations•Quality check of data: C-FMR, C-CD,•Quality check of retrieval products: C-CT, C-CLD, C-PRO• The EarthCARE CPR FMR is a 94-GHz radar network•Uses the same wavelength as the EarthCARE CPR•Closes geographical gaps of the European ground-based network• Foster the development of new Cal/Val products• Long term monitoring of the data – over years
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Cloudnet & FRM4Radar Network• Compliment the existing 94-GHz EU
network and fill gaps in under sampled
regions (Sweden & Romania)•Coverage of different cloud and climate
regimes• Instrumental synergy with ceilometer andmicrowave radiometer•
Run 94-GHz version of Cloudnet (nomicrowave radiometer needed)•Improve Cloudnet coverage•Validation of CPR retrievals• Cloudnet: Cloud target classification
algorithm (Illingworth, 2007, BAMS, Tukiainen et al., 2020, JOSS)

Svalbard,
CologneSMHI,
NorundaJOYCE, Jülich,
Cologne

ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

INOE,Magurele
Existing CloudNet station (35 GHz)
Planed CloudNet station (94 GHz)
Existing CloudNet station running a 94-GHz

ACTRIS-CloudNet classification• Cloudnet algorithm▪ Atmospheric target classification algorithm▪ Instrumental synergy✓ Radar✓ Microwave radiometer (89 GHz channel radar)✓ Ceilometer▪ Implementation of the FRM4Radar station
into the Cloudnet/ACTRIS network▪ Standardized quality controlled data set➢Collaboration with ACTRIS▪ Ze-monitoring▪ antenna miss-pointing
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Existing CloudNet station (35 GHz)
Planed CloudNet station (94 GHz)
Existing CloudNet station running a 94-GHz

ACTRIS CloudNet classification
Cloudnet Classification 13th Oct 2023NyÅlesund, SvalbardJülich, Germanysee www.cloudnet.fmi.fi for more
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Existing CloudNet station (35 GHz)
Planed CloudNet station (94 GHz)
Existing CloudNet station running a 94-GHz

Concept: Radar Ze-monitoring▪ Total system calibration monitoring▪ Based on Disdrometer radar reflectivity comparison method *Disdrometer:
optical particle counter
N(D)▪ Forward modeling of Ze
based on measured
N(D)▪ Compare forward
simulated Ze_dis toradar ZedisdrometerRadar➢ Cooperation with ACTRIS to get a standard method
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy* Kollias et al., 2019, AMT
Myagkov et al., 2020, AMT
Chellini, et al., 2022, JGR Atmos

Radar:
Measures reflectivity (Ze)of all drops in volume▪ Ze ~ N(D) D6▪ Correction of Ze forattenuation▪ Compare Ze to Ze_dis
calculated from
Disdrometer measurements

Example: Radar Ze-monitoring, JOYCE, 2019

Next project phase: Why the offset differs that much for different sites?
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Concept: Antenna pointing correction
zenith pointing antenna miss-pointed antennavhzvd

vpvv

vdvpvv

𝛟0Doppler velocity is velocity component along the line of sight••

Vd = particle fall velo + air motion
Vd = particle velo + air motion + hor wind contribution

So Vd is a function of Vh, and of the miss-pointing angle 𝛟Horizontal wind information from ECMWF IFS or retrieved from radar PPI scans
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), ItalyExample: Antenna pointing correctiona) Monitoring of the off zenith pointing
azimuth direction of miss pointing
yearly mean 𝛂

90 days of Doppler velocity measurements andwind direction data (ECMWF IFS)
Fit the model against the data set
obtain 𝛟: off zenith pointing angle
obtain 𝛂 : azimuth direction of 𝛟

off zenith pointing angle
yearly mean 𝛟

off zenith angle
received from sun scans

work in progress
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), ItalyExample: Antenna pointing correctiona) Monitoring of the off zenith pointingb) Correction of Dual Doppler velocities

azimuth direction of miss pointing
yearly mean 𝛂

off zenith pointing angle
yearly mean 𝛟

off zenith angle
received from sun scans

work in progress

Doppler velocity difference X/Ka should be 0 at cloud top
Off-zenith poiting cause errors up to 0.15 m s-1
After correction of each radar
reduction to the X- band Doppler velocity resolution

ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

CPR forward simulation tool
INPUT: ground based radar dataMotivation:• Create data base for CPR Cal/Val• Usage of existing long time data sets
• Easy usage -> python code (github)
INPUT: Ground based radar data:• Readers ACTRIS, GEOMS, airplane radar(Polar5, RASTA)• sites act as ‘ground truth’ for EarthCARE
CPR simulations• flexible satellite configuration• CloudSat• EarthCARE
Output: EarthCARE CPR view like data
• Validation of L1 with ground• Creation of long term data sets

simulator/pythontool& ACPVOUTPUT: EarthCARE synthetic CPR

ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Results• Lessens learned in radar and disdrometer operation

Cloud Radar in Cape Verde –ASKOS campaign 2021-2022• Radar data processing (Matlab on github)➢publication planned• INOE radar part of ASKOS campaign at Cape Verde➢Data uploaded to EVDC
• Simulation tool to create synthetic EarthCARE CPR data
➢Release planed soon, latest till March 2024
• FRM4Radar method on its way to be implemented inACTRIS cloud remote sensing processing▪ Ze-monitoring – ACTRIS started the implementation▪ Antenna pointing monitoring – work in progress
ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

FRM4Radar team visit
INOE, 2020

SMHI’s radar setup atNorunda

ESA-JAXA Pre-Launch EarthCARE Science and Validation Workshop | 13 – 17 November 2023 | ESA-ESRIN, Frascati (Rome), Italy

Appendix: 94-GHz cloud radar processing code
• Post-processing of the 94-GHz radar data
▪ Unfolding of the recorded Doppler spectra▪ Moment estimation: Ze, Vm, Sw and higher moments such as SK and K▪ Estimation of LDR▪ Data output in GEOMS

Radar Quicklook browser / data archivehttps://atmos.meteo.uni-koeln.de/~lpfitzen/dataBrowser/dataBrowser2.html