Off-Nadir Delta
Satellite-Based Area Monitoring Platform
Draw any area on the map.
The satellite keeps watching.
Lightning Fast
Instant satellite data access. No waiting, no complex setup. Start analyzing in seconds.
Easy to Use
Search, visualize, analyze—all with just a few clicks. No training required.
Anomaly Detection
Statistical anomaly detection alerts you when your area deviates from historical trends.
Monitor with Multiple Satellite Sources
Access Sentinel-1, Sentinel-2, VIIRS, and NASA FIRMS to monitor any region on Earth
Sentinel-2 Optical
10-meter resolution multispectral imagery. Ideal for vegetation analysis and land cover mapping.
Learn moreSentinel-1 C-Band SAR
C-band radar for surface features. Works through clouds, day or night. Perfect for flood detection.
Learn moreNISAR L-Band SAR
L-band radar penetrates forest canopy. Ideal for biomass estimation and vegetation monitoring.
Learn moreVIIRS Nighttime Lights
NASA Black Marble data showing Earth at night. Track urban development and power outages.
Learn moreActive Fire Monitoring
Near real-time fire hotspots from NASA FIRMS. VIIRS 375m resolution, updated daily. No API key needed.
Learn moreYour Own Data
Upload GeoTIFF, COG, or GeoJSON files. Combine with satellite imagery for custom analysis.
Learn moreLearn & Analyze
Step-by-step guides to help you get the most from satellite data
NDVI Vegetation Analysis
AgricultureCalculate vegetation health indices using Sentinel-2 imagery
Read guideChange Detection
AnalysisCompare satellite images before and after any event
Read guideSAR Flood Mapping
DisasterLearn to detect and map floods using radar imagery
Read guideSAR Ship Detection
MaritimeIdentify vessels in SAR imagery for maritime monitoring
Read guideFeatured Guides
Practical tutorials and technical guides for satellite imagery analysis
Getting Started with Sentinel-1 SAR Imagery: A Beginner's Guide
Learn how to access and analyze Sentinel-1 SAR radar data in your browser. This step-by-step guide covers the basics of SAR imagery, how to search for data, and interpret your first radar image.
Mapping Floods with SAR: A Practical Workflow from Search to Analysis
Step-by-step guide to delineating flood extent using Sentinel-1 SAR data. Covers pre-event baseline selection, backscatter thresholding, and common interpretation mistakes to avoid.
Understanding NDVI: How to Monitor Vegetation Health from Space
A comprehensive guide to NDVI (Normalized Difference Vegetation Index) — what it measures, how to interpret values, and practical applications for agriculture, forestry, and environmental monitoring.
Change Detection from Space: Three Approaches That Actually Work
Not all change detection methods are equal. This post compares image differencing, NDVI time-series, and SAR coherence-based approaches with real-world guidance on when to use each one.
Beyond True Color: Sentinel-2 Band Combinations Worth Knowing
Sentinel-2 has 13 spectral bands, but most people only use RGB. This post covers the most practical band combinations for agriculture, water, urban mapping, and geology — and explains why each one works.
How to Monitor Any Area with Satellite Time Series: A Complete Guide
Area monitoring with satellite time series lets you automatically track changes in any region over weeks, months, or years. Learn how to set up a monitoring zone, choose the right index, and interpret results using Sentinel-1, Sentinel-2, and VIIRS data.
Built for Satellite Monitoring
Continuous area monitoring, change detection, and active fire data — all in one platform.
Continuous Area Monitoring
Draw any area and monitor it automatically over time. Track NDVI, SAR backscatter, water indices, and more — visualized as a time series graph with anomaly detection.
Real-Time Fire Monitoring
NASA FIRMS active fire data updated daily. Overlay fire hotspots on satellite imagery to assess wildfire impact and response.
Change Detection
Compare images side-by-side with simple controls. Track changes over time. Detect patterns effortlessly.
Instant Map View
Clean, fast-loading map interface. Drag-and-drop layers. Switch views in one click. No clutter, just your data.
Quick Search
Find satellite data in seconds. Simple filters. Instant results. Access years of imagery without the wait.
One-Click Visualization
Apply different color schemes instantly. True Color, False Color, indices—all ready to use. No complex configuration.
Save & Resume
Save your work instantly. Resume anytime. Share with one link. No complicated file management.
Browser-Based, No Setup
No software to install. Access satellite imagery and analysis tools from any browser, anywhere. Start working in seconds.
Import & Overlay
Upload your own GeoTIFF, COG, or GeoJSON files. Combine with satellite data on a single map for custom analysis.
Frequently Asked Questions
Quick answers about satellite area monitoring and Off-Nadir Delta.
Off-Nadir Delta is a satellite-based area monitoring platform. Draw any polygon on the map and automatically track NDVI, SAR backscatter, active fires, and more as interactive time series with anomaly detection. It also provides direct access to Sentinel-1 SAR, Sentinel-2 Optical, NISAR L-Band SAR, VIIRS Nighttime Lights, and NASA FIRMS Active Fire data — all in your browser, no GIS software required.
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Start Monitoring Your Area Today
Join researchers and professionals monitoring environmental changes with satellite data. Free tier available.