Home Knowledge Base Start Here Curated reading ramps Paths Routes by role, mission, time Sensors How instruments observe reality Earth Obs Interpreting what sensors see Data Formats, processing, and tools Philosophy Why any of this matters Docs Product documentation

Sensors & Physics

Sensors are not cameras pointed at truth. They are instruments translating reality into constrained signals.

What Belongs Here

<ul><li>How sensors measure (and what they <em>cannot</em> measure)</li><li>Instrument constraints: geometry, noise, calibration, artifacts</li><li>The difference between <strong>measurement</strong> and <strong>interpretation</strong></li></ul>

Start Here

SAR Fundamentals SEN-005 Synthetic Aperture Radar (SAR) is a radar imaging system carried on aircraft or satellites that creates high-resolution images of the Earth's surface by emitting microwave pulses and measuring what bounces back. Unlike optical sensors that rely on sunlight, SAR generates its own illumination — so it works at night. Unlike optical sensors that are blocked by clouds, SAR's microwave frequencies pass through clouds, rain, and smoke. SAR does not see color or reflected light. It sees surface roughness, moisture content, and geometric structure. This makes it essential for flood mapping, deforestation monitoring, ground deformation measurement, and any application where persistent, all-weather observation is required. Observational Grammar OG-001 Observational Grammar (OG) is the idea that sensors — satellites, radar, spectrometers, thermal cameras — can form a language of evidence about reality that operates independently of human bias, market incentives, or bureaucratic approval chains. Just as grammar gives structure to language, OG gives structure to what instruments can claim about the physical world. It is M33's foundational concept: build systems that let reality set the table, then let markets and decisions work within those constraints, rather than the other way around.

Key Concepts

Signal vs inference
Sensors measure signals; products infer meanings.
Noise & uncertainty
Your model is only as honest as your error bars.
Geometry
Viewing angle is part of the data.

All Entries

SAR Fundamentals SEN-005 Synthetic Aperture Radar (SAR) is a radar imaging system carried on aircraft or satellites that creates high-resolution images of the Earth's surface by emitting microwave pulses and measuring what bounces back. Unlike optical sensors that rely on sunlight, SAR generates its own illumination — so it works at night. Unlike optical sensors that are blocked by clouds, SAR's microwave frequencies pass through clouds, rain, and smoke. SAR does not see color or reflected light. It sees surface roughness, moisture content, and geometric structure. This makes it essential for flood mapping, deforestation monitoring, ground deformation measurement, and any application where persistent, all-weather observation is required.

Common Failure Modes

<ul><li>Treating "preprocessed" as "objective"</li><li>Confusing image quality with inference reliability</li><li>Ignoring geometry when comparing scenes</li></ul>

Coming Next

Optical fundamentals (radiance vs reflectance), Thermal EO fundamentals, InSAR basics

Related Domains

Data & Architecture Earth Observation
esc
Domains
No results for “”
Searching…
↑↓ navigate ↵ open esc close