Sayantan Das ucalyptus

Which is better rMSE or MAE?

This depends on your loss function. In many circumstances it makes sense to give more weight to points further away from the mean--that is, being off by 10 is more than twice as bad as being off by 5. In such cases RMSE is a more appropriate measure of error. If being off by ten is just twice as bad as being off by 5, then MAE is more appropriate. In any case, it doesn't make sense to compare RMSE and MAE to each other

RMSE(t) = sqrt((t/t-1)RMSE(t-1)^2 + (1/t)(y_true(t) - y_pred(t))^2)

where t is the number of observations

Courtesy

Modification

Treat (1/t) as alpha

SAR is not compensating for the doppler of moving targets. It only compensates for the doppler shift of stationary targets as it assumes that all targets are stationary on Earth. SAR has side lobes because of which when those capture doppler, they might not suffice Nyquist criterion.

GMTI using Symmetric Defocusing

Abstract

Two filters,which differ only in the signs of the phase responses, are used to defocus the complex image respectively. In the two defocused images,each stationary target is blurred to the same extent,but each moving target is blurred to different extents. Therefore, moving targets can be indicated by patch-by-patch sharpness comparison of the two defocused images.

sudo apt-get update

sudo apt-get install vim

sudo apt-get install exuberant-ctags

	!curl -sSL "https://julialang-s3.julialang.org/bin/linux/x64/1.3/julia-1.3.1-linux-x86_64.tar.gz" -o julia.tar.gz
	!tar -xzf julia.tar.gz -C /usr --strip-components 1
	!rm -rf julia.tar.gz*
	!julia -e 'using Pkg; pkg"add IJulia; add Flux; precompile"'

	def cal_mean_spectral_divergence(band_subset):
	"""
	Spectral Divergence is defined as the symmetrical KL divergence (D_KLS) of two bands probability distribution.
	We use Mean SD (MSD) to quantify the redundancy among a band set.

	B_i and B_j should be a gray histagram.
	SD = D_KL(B_i\|\|B_j) + D_KL(B_j\|\|B_i)
	MSD = 2/n(n-1) sum(ID_ij)

	Ref: