Traditionally the main areas of ground-based remote sensing in meteorology are the observation of precipitation by weather radar and detection and localization of lightning. Nowadays also remote techniques to observe cloud height, cloud cover and aerosol layer information are emerging. For more information on these topics see the entry on surface observations.

As early registrations where merely qualitative, gradually the focus has shifted to quantitative measurements. In this field The R&D Information and Observation Technology Division is striving to enhance the reliability and capabilities of the remote sensing network and is a recognized partner in applied scientific research. Much radar and lightning detection related research initiated by Weather Research and Development is performed in close cooperation with I-RD This cooperation resulted in several publications (co-)authored by I-RD.

KNMI operates two identical Meteor 360AC C-band Doppler weather radars from SELEX, located at the KNMI premises in De Bilt and at the naval base in Den Helder respectively. In 2007 KNMI has successfully finished the upgrade of the Dutch radar network extending the operational life of the KNMI weather radar system with another 10 years by enhancing the radar processing with capabilities found in modern radar equipment. Read more in From Pulse to Product (pdf) shortly describing the KNMI weather radar production chain.

Since 1995 KNMI operates a SAFIR (Surveillance et Alerte Foudre par Interférométrie Radioélectrique) Lightning Detection System for monitoring (severe) convection and for feeding a climatological database. In 2003 the lightning detection stations and the central processor have been replaced. During the evaluation of the KNMI lightning detection system (pdf) the performance of the new lightning detection system has been compared with that of the old system.

I-RD participates in international gremia, most notably the EIG EUMETNET working group OPERA. The OPERA Programme is focusing on quality enhancement and facilitates exchange of radardata between 30 European National Meteorological Services. KNMI is the responsible member for the period 2007-1212 and I-RD is participating by delivering the national delegate for the Netherlands.

• Sun Calibration Series

It is well known that thermal radiation of the sun is perceived by the radar when scanning the hemisphere. What is new is applied research to use this stellar source as a quality monitor for radar performance. By passively analyzing the radar volume data, procedures for alignment of the antenna pointing, (low)power calibration, and monitoring of dual polarization stability are published in series of articles by Iwan Holleman

• Clutter Removal

The project QERAD is in its start up phase. In this project the filtering of the clutter (by propagation effects or man made interferences) by the radar signal processor and its subsequent processing will be analyzed and improved.

• Upcoming: Dual Polarization Radars

As our radars are to be replaced by new dual polarization equipment from 2016 onward, it is important to gain knowledge on the techniques available and products that will be generated. This work will start soon, in order to make this transition smooth, and effective from the start of the operation of the new network.

• Lightning Detection endUser Requirements

Goal of this project is defining end user requirements with regard to lightning detection, and map these on the instrumental and functional setup of lightning detection KNMI wishes to reach for the period 2011-2020. Within the framework of this project an inventory of end user requirements and a survey of available solutions have been accomplished.