Update CHANGELOG.md with changes in obsFilt.m and rearranged the updates a bit

CHANGELOG.md

@@ -2,6 +2,9 @@
 **Signal Processing - Generic**\
 \* Fix bug returning wrong length filter when negative delays are use in `winSincFracDel()`.
 
+**Signal Processing - Measurements**\
+\* Fix error in `invSweep()` throwing an error when the `causIrLen` input argument was not provided.
+
 **Signal Processing - Array Processing**\
 \+ Add function to calculate the time-domain equivalent of the *array manifold* of an arbitrary array.\
 \* Changed the name of `firstOrderDMA()` to `firstOrderDma()` (cameltoe). This change **breaks** backward compatibility!\
@@ -10,9 +13,6 @@
 \* Correct erroneous output calculations in `firstOrderDma()`.
 \* Moved the `input` input argument to the last of the input arguments list and updated the input argument checks. This change **breaks backward compatibility**. 
 
-**Signal Processing - Measurements**\
-\* Fix error in `invSweep()` throwing an error when the `causIrLen` input argument was not provided.
-
 **Optimisation - Memetic Algorithm**\
 \* Removed redundant code to handle serial for-loop if parfor is not available.
 
@@ -28,7 +28,8 @@
 \* Parallelise the for-loops in `obsFiltEst()`. While execution may be slower for a small number of sources and receiver positions, the overall execution time will not increase significantly due to the functions' generally fast performance.\
 \* Parallelise on of the for-loops in `obsFiltTD()`. While execution may be slower for a small number of sources and receiver positions, the overall execution time will not increase significantly due to the functions' generally fast performance.\
 \* Change function name from `obsFiltTD()` to `obsFiltTd()`.\
-\* Change function name from `obsFiltEstTD()` to `obsFiltEstTd()`.
+\* Change function name from `obsFiltEstTD()` to `obsFiltEstTd()`.\
+\* Update `obsFilt()` to return the condition of the perturbed power spectral density matrix.
 
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