Data products

TROLIX'19 Campaign

TROLIX’19 – TROpomi vaLIdation eXperiment 2019

A Sentinel-5p/TROPOMI validation campaign will be held in the Netherlands based at the Cabauw Experimental Site for Atmospheric Research during September 2019. The TROpomi vaLIdation eXperiment (TROLIX) consists of active and passive remote sensing platforms in conjunction with several balloon-borne, airborne and surface chemical measurements. The goal of this geophysical validation campaign is to make intensive observations to establish the quality of TROPOMI L2 main data products (UVAI, Aerosol Layer Height, NO2, O3, HCHO, Clouds) under realistic non-idealized conditions with varying cloud cover and a wide range of atmospheric conditions.

Since TROPOMI is a hyperspectral imager with a very high spatial resolution of 3.5x7 km2, understanding local effects such as inhomogeneous sources of pollution, sub-pixel clouds and variations in ground albedo is important to interpret TROPOMI results. Therefore, the campaign includes sub-pixel resolution local networks of sensors, involving Pandora and MAXDOAS instruments, around Cabauw (51.97° N, 4.93° E) and within the city of Rotterdam. Cabauw is considered rural while Rotterdam is densely populated and industrialized. These focal areas will be connected through airborne as well as ground based mobile observations. Cabauw, using its comprehensive in-situ and remote sensing observation program in and around the 213 m meteorological tower, will be the main site of the campaign with focus on vertical profiling using lidar instruments for aerosols, clouds, water vapor, tropospheric and stratospheric ozone, as well as balloon-borne sensors for NO2 and ozone.

The data set collected can be directly compared to the TROPOMI L2 data products, while measurements of parameters related to a-priori data and auxiliary parameters that influence the quality of the L2 products such as aerosol and cloud profiles and in-situ aerosol and atmospheric chemistry will also be collected.

The campaign will be supported by satellite observations and atmospheric modelling (CAMS).

TROLIX Campaign Schedule

Date Activities

Mon 26 Aug through Fri 30 Aug

Instrument & Site Set Up

Mon 02 Sep through Fri 06 Sep

Warm-up, Instrument Testing phase

Mon 09 Sep through Fri 27 Sep

Intensive Observation Period

Mon 30 Sep through Sun 06 Oct

Possible Extension

Mon 07 Oct through Fri 11 Oct

Site break down


For further inquiries and requests, please contact:

Arnoud Apituley - campaign lead (apituley [at]

Karin Kreher - campaign support (karin.kreher [at]