1. The stated objective is to apply mapping technique that helps in analyzing digital photos that shows light polluted areas: 
   a. The research introduced that technique as a “visual tool”, it would be helpful to mention why the digital photographs are not enough to give an idea regarding the light pollution intensity? 
   b. And why the Inverse Distance Weighted (IDW) is better than other “interpolation models” that create continuous surface mapping?

2. In section 3.1.2, the photometric survey procedure needed to be explained clearly by having diagrams that show how and where the reading points were taken vertically.

3. Also how those readings were associated with the digital images? On a grid or through a vertical section on one line? Also, did the researcher get any benefits out of those readings or relied only on the digital image pixels’ illumination?

4. A brief introduction to the “Surface approximation of point data using different interpolation techniques” in the GIS would be useful to the reader and helps to understand the validity of the process. 

5. Some work is needed in figures and charts; the flow chart in Figure 3 is not readable, multiple images in one figures need to have titles (a, b, c).

6. Graphs are not informative and need significant corrections:

   a. The “x” axis has no units so the distance between columns is not relevant if there are no units or legend. 
   b. Two graphs have same title (graph 1 in page 10) 
   c. The legend has numbers that define the pollution columns, but no clue what those numbers are standing for? Values? Distances? Areas? Intensity? 
   d. Graph 4 (which comes before graph 3 !) has on Y axis numbers indicated as “value”; what value? And the X axis has neither value nor a legend.

7. English need some revisions regarding spelling, grammar, and style. 
