Blog

This guide shows you where to find the best free satellite imagery , how to download it , how to use it in QGIS , where to get near–real-time images, and what matters when choosing the right dataset. You’ll also see how OnGeo simplifies the whole process by providing ready-made satellite reports with no accounts, no subscriptions, and zero technical skills required.

What Is Satellite Imagery? Satellite imagery refers to pictures of Earth captured by sensors mounted on satellites orbiting the planet. These sensors detect reflected light, emitted radiation, or other wavelengths to record what is happening on the surface below. The result is data—often visual, sometimes multispectral or thermal—that can be analyzed to understand land use, vegetation, infrastructure, water bodies, environmental change, and much more.

This article explains the differences between Digital Elevation Models (DEMs), Digital Terrain Models (DTMs), and Digital Surface Models (DSMs) in satellite Earth observation. It covers their definitions, applications, and data sources, including optical satellites, radar, and LiDAR. By clarifying these concepts and their specific uses, readers will better understand how to select the right elevation model for urban planning, forestry, hydrology, renewable energy, and disaster management.

Satellite image resolution determines how much detail a satellite can capture—from broad environmental patterns to fine-scale urban features. Understanding the differences between low and high resolution helps professionals choose the right data for climate monitoring, urban planning, agriculture, and disaster response.

What’s happening in the forests of eastern DRC isn’t just a side effect of war - it’s part of how armed groups survive and finance their operations. Thanks to modern satellite technology, the scale and pace of this destruction can finally be tracked, measured and documented with a level of detail that wasn’t possible before. This article outlines what satellite imagery reveals, why these findings matter.

Sentinel-6B, the twin of Sentinel-6 Michael Freilich, was successfully launched on November 17, 2025 aboard a SpaceX Falcon 9 from Vandenberg Space Force Base. The new Copernicus climate satellite will ensure uninterrupted, centimeter-accurate monitoring of global sea-level rise - a critical climate indicator - through at least 2030 and beyond.

Satellite imagery has transformed how we understand our planet. This article explains how data is captured in orbit, processed on the ground, and turned into the clear, actionable visuals we use for weather tracking, urban planning, environmental monitoring, and scientific analysis.

Satellites and remote-sensing technologies are revolutionizing how we observe and understand our planet. This glossary breaks down essential terms - from NDVI and SAR to LEO orbits and Sentinel satellites-making it easier to navigate the world of Earth observation, geospatial analysis, and AI-powered mapping.

Background: The Conflict Behind the Al-Fashir Massacre The massacre in Al-Fashir did not happen in isolation. It is part of a broader civil conflict that erupted in April 2023, when tensions between Sudan’s two most powerful military factions - the Sudanese Armed Forces (SAF) , led by General Abdel Fattah al-Burhan, and the Rapid Support Forces (RSF) , commanded by Mohamed Hamdan Dagalo (“Hemedti”) - escalated into full-scale war.