  We analyse the time series of solar irradiance measurements using chaos
theory. The False Nearest Neighbour method (FNN), one of the most common
methods of chaotic analysis is used for the analysis. One year data from the
weather station located at Nanyang Technological University (NTU) Singapore
with a temporal resolution of $1$ minute is employed for the study. The data is
sampled at $60$ minutes interval and $30$ minutes interval for the analysis
using the FNN method. Our experiments revealed that the optimum dimension
required for solar irradiance is $4$ for both samplings. This indicates that a
minimum of $4$ dimensions is required for embedding the data for the best
representation of input. This study on obtaining the embedding dimension of
solar irradiance measurement will greatly assist in fixing the number of
previous data required for solar irradiance forecasting.
