QUESTION:
I would like to know, what algorithm ECOTECT uses for calculating the azimuth and altitude of sun at a particular time ?
ANSWER:
Sun position calculations in all Square One software are based on work by Carruthers et.al., who carried out an extensive study of existing formulae for declination and the equation of time against recorded tables over a 50 year period, and derived a more accurate equation.
The main reference is as follows:
Carruthers, D.D., Roy, G.G. and Uloth, C.J. 1990, An Evaluation of Formulae for Solar Declination and the Equation of Time, Research Report No. 17, School of Architecture, The University of Western Australia.
For anyone who is
For anyone who is interested I have been able to locate a reference to the algorithm proposed by Carruthers et.al. in another paper that has been published in full online.
It can be found here with the algorithm given on the last page of the publication.
Unfortunately without receiving permission from the authors/publishers of the original paper we are unable to provide an online copy for reference.