  The most challenging limitation in transit photometry arises from the noises
in the photometric signal. In particular, the ground-based telescopes are
heavily affected by the noise due to perturbation in the Earth's atmosphere.
Use of telescopes with large apertures can improve the photometric
signal-to-noise ratio (S/N) to a great extent. However, detecting a transit
signal out of a noisy light curve of the host star and precisely estimating the
transit parameters call for various noise reduction techniques. Here, we
present multi-band transit photometric follow-up observations of five
hot-Jupiters e.g., HAT-P-30 b, HAT-P-54 b, WASP-43 b, TrES-3 b and XO-2 N b,
using the 2m Himalayan Chandra Telescope (HCT) at the Indian Astronomical
Observatory, Hanle and the 1.3m J. C. Bhattacharya Telescope (JCBT) at the
Vainu Bappu Observatory, Kavalur. Our critical noise treatment approach
includes techniques such as Wavelet Denoising and Gaussian Process regression,
which effectively reduce both time-correlated and time-uncorrelated noise
components from our transit light curves. In addition to these techniques, use
of our state-of-the-art model algorithms have allowed us to estimate the
physical properties of the target exoplanets with a better accuracy and
precision compared to the previous studies.
