Estimation of Daily Global Solar Radiation

Oct 13, 2025 by wbrum.org 92 views

Introduction to RadEst

RadEst is a powerful program designed to evaluate and estimate daily global solar radiation values for a specific location at a given latitude. This tool allows users to estimate daily values using four different models, all derived from the model proposed by Bristow and Campbell. These models estimate atmospheric transmissivity of global solar radiation based on the difference between maximum and minimum temperature. The estimated value of radiation is calculated as the product of the estimated transmissivity times the value of potential radiation outside the earth atmosphere.

Key Features of RadEst

Estimation of Daily Global Solar Radiation: RadEst allows users to estimate daily global solar radiation values for a specific location at a given latitude.
Four Models for Estimation: The program includes four models for estimating daily radiation from air temperature data, all derived from the model proposed by Bristow and Campbell.
Graphical Evaluation: Utilities are available for a graphical evaluation of the estimates and compute statistical indices for model/location comparison.
Parameter Fitting: Parameters can be fitted using iterative procedures either minimizing the amount or the pattern of residuals.
Data Analysis: One year or more than one year (at most twenty) of daily data can be used to estimate one parameter for each model.
Saving Estimated Values: Estimated values can be saved as ASCII files.
Trend Evaluation: Trends over years in measured data can be evaluated graphically.
Bias Correction: Constant bias in measured radiation data can be evaluated and corrected, saving the corrected files.

New Features in Version 3

Version 3 of RadEst includes several new features that enhance its functionality and usability. Some of the key features include:

New Model for Tropical Sites: A new model specifically developed for tropical sites is included in Version 3.
Modular Model: A modular model is included, which allows including/excluding different components from the three models implemented.
Sample Data Set: A sample data set of tropical and temperate sites is provided.
Parameter File: A parameter file for tested locations is also provided.
Reporting Capabilities: Reporting capabilities are included, allowing users to browse and print the analysis performed; reports can be saved and exported in a variety of formats, including MS Excel and HTML.

Estimation of Potential Evapotranspiration

RadEst also allows users to estimate potential evapotranspiration using either the Penman-Monteith or the Priestley-Taylor method. This can be done using both the measured and the estimated radiation data. The estimated values of potential evapotranspiration can be saved as ASCII files.

Batch Run Utility

A batch run utility is included in RadEst, which allows users to process easily a large number of files. This feature is particularly useful for users who need to analyze a large dataset.

Conclusion

RadEst is a comprehensive tool for evaluating and estimating daily global solar radiation values. Its key features, including the estimation of daily global solar radiation, four models for estimation, graphical evaluation, and parameter fitting, make it a valuable resource for researchers and scientists in the field of solar radiation and evapotranspiration. The new features included in Version 3 enhance its functionality and usability, making it an even more powerful tool for users.

Frequently Asked Questions about RadEst

RadEst is a powerful program designed to evaluate and estimate daily global solar radiation values for a specific location at a given latitude. In this article, we will answer some of the most frequently asked questions about RadEst.

Q: What is RadEst and what does it do?

A: RadEst is a program designed to evaluate and estimate daily global solar radiation values for a specific location at a given latitude. It uses four different models to estimate daily radiation from air temperature data.

Q: What are the four models used in RadEst?

A: The four models used in RadEst are all derived from the model proposed by Bristow and Campbell. They estimate atmospheric transmissivity of global solar radiation based on the difference between maximum and minimum temperature.

Q: How do I use RadEst to estimate daily global solar radiation values?

A: To use RadEst to estimate daily global solar radiation values, you need to input the location's latitude and the air temperature data. The program will then use the four models to estimate the daily radiation values.

Q: Can I save the estimated values as ASCII files?

A: Yes, you can save the estimated values as ASCII files. This allows you to easily import the data into other programs for further analysis.

Q: Can I evaluate trends over years in measured data using RadEst?

A: Yes, you can evaluate trends over years in measured data using RadEst. The program includes a graphical evaluation tool that allows you to visualize the trends.

Q: Can I correct constant bias in measured radiation data using RadEst?

A: Yes, you can correct constant bias in measured radiation data using RadEst. The program includes a bias correction tool that allows you to evaluate and correct the bias.

Q: What are the new features included in Version 3 of RadEst?

A: Version 3 of RadEst includes several new features, including a new model specifically developed for tropical sites, a modular model that allows including/excluding different components from the three models implemented, a sample data set of tropical and temperate sites, a parameter file for tested locations, and reporting capabilities.

Q: Can I estimate potential evapotranspiration using RadEst?

A: Yes, you can estimate potential evapotranspiration using RadEst. The program includes two methods for estimating potential evapotranspiration: the Penman-Monteith method and the Priestley-Taylor method.

Q: Can I save the estimated values of potential evapotranspiration as ASCII files?

A: Yes, you can save the estimated values of potential evapotranspiration as ASCII files. This allows you to easily import the data into other programs for further analysis.

Q: Is there a batch run utility available in RadEst?

A: Yes, there is a batch run utility available in RadEst. This allows you to process easily a large number of files.

Q: Is RadEst available for Windows?

A: Yes, RadEst is available for Windows. The program is designed to run on Windows operating systems.

Q: Is RadEst available for free?

A: No, RadEst is not available for free. However, the program is available for purchase and can be downloaded from the official website.