Thank you guys Rugged, Mark and AWOL for your time to answer my query.
I do not know if my question is stupid, but i am curious to ask it. Suppose i keep my object at 1m distance, then the distance for the wave to reach the object and come back will be totally 2 meters.
Since i am dealing with millimeters with decimal places like 0.001mm, I would like a clarification with the below sample scenario.
Speed of Sound = 334 m = 334000 mm
Total Distance to be travelled by the wave = 2m = 2000mm
Time taken in Seconds = 2000 / 334000 = 0.0059880239520958
Time taken in Milli Seconds = 5.9880239520958
Time taken in Micro Seconds = 5988.0239520958
Now the sensor is moved by 0.1 mm horizontally and parallel with the surface and the vertical distance between the sensor and the surface increasing by 0.001 mm,
Then it will be
Total Distance to be travelled by the wave = 2m(roughly) = 2000.001 mm
Now the time taken in Seconds = 2000.001 / 334000 = 0.0059880269461078
Time taken in Milli Seconds = 5.9880269461078
Time taken in Micro Seconds = 5988.0269461078
Now the difference between time taken for Point 1 and Point 2 in micro seconds is = 0.002994012
Hence i thought i will use these value of differences to analyze the surface initially and monitor the same area often to see how the surface changes(i mean becoming flat).
So this was the basic idea for which i thought will use the Arduino board and the ping sensor. Please feel free to correct me if i am wrong. Also what are the pitfalls in this technique. To my understanding one pitfall i could see is the double numbers. But i could see that arduino supports Double values too http://www.arduino.cc/en/Reference/Double
I am planning to get the data from the sensor and paint a graph in Flash. Since this is the objective i thought this approach will help solve the problem.