That's because of interference from ice crystals in clouds.
The sensor cant penetrate the interference.
This is from the Germans. They are trying to get the EU, jaxa, nasa, the Indians, the Dutch, and the Chinese to help fund this massive satellite project to bring low frequency with little to no interference at a high resolution.
It would Be the ultimate game changer. If you don't wish to take my word for it. Orh will confirm this.
CIMR: a Game-Changer
LAST UPDATED: JUNE 20, 2018
In February 2018, for an invited post at the EGU Cryospheric Science blog, Thomas Lavergne discussed how the Copernicus Imaging Microwave Radiometer (CIMR) could be a game-changer for operational monitoring of sea-ice.
He wrote:
Before I tell you what makes CIMR so special, we need a short introduction on what passive microwave instruments are, why we like them for observing sea ice, and how they work:
One of a kind, the CIMR will focus on the low frequencies (6, 10, and 18 GHz), and fly an antenna big enough to ensure much better resolution than any of the passive microwave instruments we ever used before. This requires the antenna of CIMR to be substantially largerthan that of SSMIS (60cm diameter), MWI (75cm) or even AMSR2 (2.1m)! The AMSR-E instrument and its follower AMSR2 were game-changers 15 years ago, and still offer the best resolution today… but future operational models and polar applications will require better sea ice products all too soon.
An exciting time opens for satellite-based observations of polar sea ice, as the pre-studies for CIMR are started by the European Space Agency this spring! Will industry take-up the challenge and build a big enough antenna for CIMR? Will CIMR be selected as EU’s future polar Copernicus mission? If “yes” to both, Europe will have a game-changer: high-resolution all-weather daily global accurate mapping of sea ice concentration.