De or het radarstraling?

The correct Dutch article is:

de radarstraling

Rule Words ending in -ing: almost always de. See the rule

How to use radarstraling

the radarstralingde radarstraling
this radarstralingdeze radarstraling
that radarstralingdie radarstraling
our radarstralingonze radarstraling
your radarstralingjouw radarstraling
every radarstralingelke radarstraling
which radarstraling?welke radarstraling?
a big radarstraling / the big radarstralingeen grote radarstraling, de grote radarstraling