Terrain Albedo Mapping via Digital Camera Calibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Characterizing the albedo of a terrain surface is challenging due to the high cost and limitations of conventional albedometers, which are expensive and difficult to transport, leading to uncertainties in estimating photovoltaic output gains for bifacial photovoltaic modules.
Innovation Solution
A method using a digital camera and a target with known albedo to acquire and process digital images, correcting pixel intensities with a calibration matrix to determine the albedo map of the terrain, allowing for low-cost, rapid, and direct mapping of albedo without the need for conventional albedometers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional albedometers are used to measure land surface albedo, then measurement precision is improved, but device complexity and cost increase significantly
Solution Approach 1:
The patent uses a digital camera to capture images of the terrain and a reference target with known albedo. By processing these images through calibration and correction algorithms, the system creates a virtual representation of the terrain's albedo distribution without requiring physical albedometers on the ground.
Solution Approach 2:
The patent replaces the mechanical/al optical measurement system of conventional albedometers with a digital imaging system. Instead of using specialized albedometer hardware to directly measure reflectance, the system uses camera images processed through computational algorithms to derive albedo values.
2Measurement precision
If conventional albedometers are used to map albedo across entire sites, then measurement precision is improved, but transport and installation difficulty increase
Solution Approach 1:
The system creates a digital copy of the terrain's albedo characteristics through camera imaging. This virtual albedo map can be generated without physically transporting and installing multiple albedometers across the site, as the camera can capture the entire terrain from a single location.
Solution Approach 2:
The patent transitions from point-measurement albedometers to a two-dimensional imaging approach. By using camera images that capture the entire terrain area, the system maps albedo across the whole site in a single operation rather than requiring multiple point measurements.
3Measurement precision
If multiple albedometers are used to map albedo across entire sites, then measurement precision is improved, but cost increases substantially
Solution Approach 1:
The system uses a single digital camera to capture images of the entire terrain and processes these images computationally to generate albedo maps. This eliminates the need to purchase, transport, and deploy multiple expensive albedometers, significantly reducing project costs while maintaining mapping precision.
Solution Approach 2:
The patent makes the camera serve multiple functions: it captures images for albedo mapping, provides reference data through the known-albedo target, and enables calibration of the measurement system. This multi-functionality replaces the need for multiple specialized albedometers.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate, cost-effective, and efficient mapping of albedo across large areas, facilitating optimal placement of bifacial photovoltaic modules by providing precise estimates of photovoltaic output gains.
Implementation Method 1
bifacial photovoltaic modules collect sunlight not only from their top surface (directly exposed to the sun), but also from their back surface the light reflected by the ground
Data Source
Figure 1
Figure 2
AI summary
The invention concerns the characterisation of an albedo of a piece of land, from a digital image acquired of this land using one or more cameras (CAM1, CAM2), in particular in order to optimise the arrangement of bifacial photovoltaic modules on this land. It involves: - a prior calibration of the camera, in which an intensity correction matrix of each image pixel (x, y) acquired by the camera is acquired, and - a current characterisation of the albedo of a piece of land on which a test pattern (REF), of known albedo αRéférence, is deposited on the ground so as to be present in a current image acquired with the same camera, this current characterisation of the albedo of the land being carried out by processing the current image in a processing circuit (CT), with correction (Formula I) of the current image by applying the correction matrix. The average light intensity (Formula II) of the test pattern appearing in the corrected image is then estimated, in order to determine an albedo map of the land αSite(x, y) based on the known albedo of the test pattern αRéférence, by a relationship of the following type: (Formula III).