Skip to main content
Log in

Generation of common coefficients to estimate global solar radiation over different locations of India

  • Original Paper
  • Published:
Theoretical and Applied Climatology Aims and scope Submit manuscript


In developing countries like India, global solar radiation (GSR) is measured at very few locations due to non-availability of radiation measuring instruments. To overcome the inadequacy of GSR measurements, scientists developed many empirical models to estimate location-wise GSR. In the present study, three simple forms of Angstrom equation [Angstrom-Prescott (A-P), Ogelman, and Bahel] were used to estimate GSR at six geographically and climatologically different locations across India with an objective to find out a set of common constants usable for whole country. Results showed that GSR values varied from 9.86 to 24.85 MJ m−2 day−1 for different stations. It was also observed that A-P model showed smaller errors than Ogelman and Bahel models. All the models well estimated GSR, as the 1:1 line between measured and estimated values showed Nash-Sutcliffe efficiency (NSE) values ≥ 0.81 for all locations. Measured data of GSR pooled over six selected locations was analyzed to obtain a new set of constants for A-P equation which can be applicable throughout the country. The set of constants (a = 0.29 and b = 0.40) was named as “One India One Constant (OIOC),” and the model was named as “MOIOC.” Furthermore, the developed constants are validated statistically for another six locations of India and produce close estimation. High R2 values (≥ 76%) along with low mean bias error (MBE) ranging from − 0.64 to 0.05 MJ m−2 day−1 revealed that the new constants are able to predict GSR with lesser percentage of error.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3

Similar content being viewed by others


Download references


The authors wish to thank the India Meteorological Department and Central Research Institute for Dryland Agriculture for providing the solar radiation and the bright sunshine hour data.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Saon Banerjee.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Samanta, S., Patra, P.K., Banerjee, S. et al. Generation of common coefficients to estimate global solar radiation over different locations of India. Theor Appl Climatol 136, 943–953 (2019).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: