Overview

Patent Pending in The United States of America
System and Method for Indirect Estimation of Solar Irradiance and Heat Flux via Differential Thermodynamic Sensing
US 63/937,986 · Filed December 29, 2025

Modern environmental monitoring systems, from automotive platforms to industrial installations, often rely on sensing architectures decades old. While sensor hardware has plateaued, algorithmic processing potential has grown exponentially. This creates an engineering challenge as billions of functional sensors are discarded annually, perceived as incapable of advanced measurements like solar radiation or heat flux.

This technology mitigates hardware obsolescence by transferring computation from physical components to intelligent software. By upcycling commodity sensors into high-precision radiometric instruments without firmware changes, it preserves global sensor infrastructure utility in modern autonomous frameworks.

The core is the Differential Temporal Derivative Soft-Sensing (DTDSS) framework, replacing expensive and fragile specialized equipment like pyranometers which are prohibitive in autonomous systems. It uses a differential thermodynamic architecture with paired sensors: a Reference Node alongside a Flux Node to isolate active energy exchanges from ambient conditions. An Inertial Noise Reduction (INR) filter compensates for thermal inertia, predicting equilibrium temperatures in real time.

Unlike machine learning approaches, this system uses physics-based derivations. Air density and enthalpy are calculated via first-principles thermodynamics, ensuring accuracy across altitudes and climates. The state machine is optimized for extreme efficiency, requiring under 60 bytes of RAM, compatible with 8-bit microcontrollers.

FIA Operating Systems is a network of scientists, developers, and industry professionals advancing hardware-agnostic solutions for global sustainability. This ensures established innovations continue contributing to a data-rich, sustainable future.

Billions of sensors exist measuring simple parameters only because that is how they were labeled. The true value of mathematical approximation is often overlooked. A combination of such sensors can yield derived parameters, values that cannot be obtained directly with perfect precision. However, perfect precision is not always required.

Restricting sensor potential limits future generations from building upon current work. Sensors, old or new, built for various purposes, when combined together, can derive far more advanced real-world parameters in applications that do not demand absolute precision. FiaPhy is a research initiative focused on maximizing the potential of sensors, the near-future carriers of full-human automation, to help sustain existing and upcoming innovations while enabling them to work with these frameworks for generations to come.

Research contributions or technical collaboration inquiries may be directed to research@fiaos.org.

Research & Publications

Temporal Derivative Soft-Sensing and Reconstructing Solar Radiation and Heat Flux from Common Environmental Sensors and FiaOS Engineering

Preprint - Under IEEE Review
Neksha V. DeSilva November 25, 2025 Environmental Engineering, Soft-Sensing, IoT Systems

This paper introduces Differential Temporal Derivative Soft-Sensing (DTDSS), a physics-based framework that transforms standard, low-cost environmental sensors into capability-dense radiometers. By employing a differential topology with Inertial Noise Reduction (INR), the system mathematically reconstructs Global Horizontal Irradiance (GHI) and convective heat flux without expensive thermopile pyranometers. The research demonstrates how to upgrade millions of existing and future IoT devices to derive complex energy flux parameters from common sensors.

FiaPhy Library

Development Updates & Networks

Publications

Preprint - Under review [pdf]

Temporal Derivative Soft-Sensing and Reconstructing Solar Radiation and Heat Flux from Common Environmental Sensors and FiaOS Engineering

IIndependent researcher, FiaOS.org | Dated: November 25, 2025
Subjects: Environmental Engineering; Soft-Sensing; Solar Radiation (physics.ao-ph); IoT Systems
Summerized Abstract

Current environmental monitoring is fundamentally limited by a reliance on static state variables, temperature, pressure, and humidity, while remaining blind to the dynamic energy exchanges that drive them. This paper introduces Differential Temporal Derivative Soft-Sensing (DTDSS), a novel physics-based framework that transforms standard, low-cost environmental sensors into capability-dense radiometers. By employing a differential topology with Inertial Noise Reduction (INR), we can mathematically reconstruct Global Horizontal Irradiance (GHI) and convective heat flux without the cost or fragility of thermopile pyranometers. While validated using the FiaOS reference architecture, this methodology is hardware-agnostic. The ultimate vision of this work is the deployment of a high-performance, open-source computational library designed for professional embedded development environments. By distributing this algorithm via global repositories, we aim to upgrade the capabilities of millions of existing and future IoT devices. This library allows standard electronics to move beyond simple linear measurements and unlock higher-order environmental physics. By deriving complex energy flux parameters from common sensors, we open a new frontier of derived equations and applications, from precision agriculture to autonomous energy management, essentially democratizing advanced meteorological physics for the global engineering community.