Remote Sensing
Comprehensive guides on mission constellations, spectral band mechanics, indices algorithms, and planetary observation applications.
Landsat 8 Satellite
Multi-spectral satellite with 30m resolution
Landsat 8 is a joint mission between USGS and NASA launched in 2013. It carries the OLI sensor with 11 bands covering visible, NIR, SWIR, and thermal regions.
Sentinel-2 Constellation
European multi-spectral satellite with 10m resolution
Sentinel-2 consists of two identical satellites (2A and 2B) providing 10-20-60m resolution with 13 bands for land monitoring.
MODIS (Aqua/Terra)
Low-resolution daily satellite for large-scale monitoring
MODIS offers 250m-1km resolution with 36 bands. Terra and Aqua provide daily global coverage for atmospheric and ocean monitoring.
Landsat 9 Satellite
Latest Landsat mission with improved radiometric performance
Landsat 9 launched in 2021, carries OLI-2 and TIRS-2 sensors with 14-bit radiometric resolution for enhanced dynamic range and improved data quality.
Spectral Window Reference
Visible Light (0.4-0.7 μm)
Blue, Green, Red bands used for natural color imagery, coastal mapping, and basic vegetative monitoring.
Near-Infrared (0.7-1.3 μm)
Highly sensitive to vegetation cellular structure, making it critical for NDVI and health dynamics.
Thermal Infrared (8-14 μm)
Emitted entirely from the Earth's surface; measures kinetic heat for urban heat islands and sea surface temperatures.
Microwave (1mm - 1m)
Used by SAR (Synthetic Aperture Radar) like Sentinel-1. Can penetrate clouds and operate at night.
Industrial Applications
Land Classification
Monitor shifting LULC over time using random forest.
Vegetation Health
Track agricultural yields with NDVI chronologies.
Hydrology
Identify floods with SAR or calculate NDWI.
Urban Growth
Analyze sprawl via NDBI and nighttime lights.
Disaster Response
Assess earthquake/fire damage continuously.
Cryosphere
Track glacier retreat and sea ice extents.