The best thing about Earth observation lies in its ability to unlock unparalleled insights about our planet, from tracking hurricanes to monitoring deforestation. But for decades, there has been one persistent challenge that has clouded (pun intended) the field: cloud coverage. At any given time, about 60% of the Earth is covered by clouds, and in particularly humid or tropical regions, that number can soar even higher. For scientists, governments, and organizations relying on optical satellite imagery, this has been a frustrating limitation.
But where there’s a challenge, innovation often follows. Let’s dive into the history of Earth observation’s "Cloud Problem," explore how technologies have evolved, and see how Capella Space is solving this issue with Synthetic Aperture Radar (SAR).
The "Cloud Problem" Through History
The challenge of cloud coverage dates back to the early days of Earth observation in the 1960s. Optical imaging, which captures images using visible and infrared light, was the primary method for observing the planet from space. While revolutionary at the time, optical systems had one glaring flaw: they were completely dependent on clear skies and daylight.
For regions frequently shrouded in clouds—such as rainforests, coastal areas, and disaster zones—this meant a significant gap in data collection. Critical events like hurricanes, wildfires, or landslides often went unmonitored until clouds cleared, delaying response times and impacting decision-making.
In the 1970s, radar technology began to emerge as a potential solution. Synthetic Aperture Radar, developed initially for military applications, uses microwaves instead of light to collect images. Microwaves can penetrate through clouds, smoke, and even darkness, making them a game-changer for all-weather, anytime observation.
How Radar Changed the Game
SAR technology fundamentally shifted the landscape of Earth observation. Unlike optical systems that are hindered by clouds and darkness, SAR satellites use active sensors to emit microwave signals, which bounce off the Earth's surface and return to the satellite. By analyzing the returning signals, SAR creates detailed, high-resolution images that are independent of weather or lighting conditions.
One of the earliest civilian SAR missions was the SEASAT mission launched by NASA in 1978. Although its operational life was short (just 105 days), SEASAT demonstrated the potential of SAR to gather data regardless of cloud coverage. The 1990s saw more sophisticated SAR systems, such as the ERS-1 and ERS-2 missions by the European Space Agency, which solidified SAR’s role in environmental monitoring.
The Persistent Need for Cloud-Free Imagery
Fast forward to today, and the "Cloud Problem" is still very real. From hurricane-prone areas in the tropics to industrial zones in temperate regions, cloud coverage continues to hinder optical imaging. This is especially critical in applications like:
Disaster Response: Flooded regions or wildfire zones often remain obscured by clouds during the events themselves.
Environmental Monitoring: Changes in forest cover, ice melt, and agriculture can’t wait for clear skies.
Infrastructure Surveillance: Urban and industrial areas require frequent updates that aren’t always possible with optical systems.
In essence, relying on optical imaging alone means missing out on significant portions of the picture—literally.
Capella Space’s SAR: A Modern Solution
As the first U.S Commercial SAR company, Capella Space has taken SAR technology to the next level. Our advanced constellation of SAR satellites is designed to provide all-weather, anytime imagery with unprecedented clarity and speed. Here’s how we’re leading the charge:
1. Breaking Through Clouds and Darkness
Capella’s SAR satellites operate in the microwave spectrum, making them immune to cloud coverage, smoke, or even total darkness. This means we can collect data 24/7, ensuring uninterrupted monitoring.
2. Unparalleled Resolution
With imaging capabilities that rival—and often surpass—optical systems, Capella’s SAR technology offers detailed views of Earth’s surface. Manmade objects, natural features, and even subtle changes are captured with precision.
3. Rapid Tasking and Delivery
Capella’s system is built for speed. Customers can request SAR images on demand and receive data within hours, making it ideal for time-sensitive applications like disaster response or real-time monitoring.
A Cloud-Free Future for Earth Observation
The evolution of Earth observation has been a journey from reliance on clear skies to full independence from weather and storm conditions. Today, SAR technology is enabling us to monitor our planet more effectively than ever before. At Capella Space, we’re proud to be part of this transformation, providing reliable, actionable data when it matters most.
Interested in seeing how SAR cuts through the clouds? Check out Capella Space’s SAR Image Gallery or learn more about our technology on our About SAR page.
Sources and Further Reading
NASA’s NEO Cloud Fraction
NASA Terra
Capella Space Open Data Gallery
At Capella, we’re paving the way for a future where no insight is lost to the "Cloud Problem." Learn more about our technology here.