Tartan

Monday, March 27, 2006

Let there be light

The journey of Tartan continues with a stronger version of Hope that made us toil day and night to find some light for our BE Project. The very quote I would have uttered " Let there be light" hoping to find out the answers and have a mental illumination.

Let there be Light

Science has emerged when the knowledge of the past has been recognized as inadequate to answer certain questions and questions that past could not think of. There is a theorem that describes how has science graduated. In the beginning, God said “Let there be light” and there was Socrates who provided inductive thoughts to answer ‘what’ questions, and then planets were given names. Later Galileo, Copernicus had to counter many adversaries to prove their heresy! God again said “Let there be light” and there was Newton who provided deductive thoughts to answer ‘how’ questions. Later God said “Let there be light” and there came Einstein who provided reductive thoughts to answer ‘why’ questions. We had to answer the same set of questions “What to do in this project?”, “How to do it?” and more fundamentally “Why do it?” before us. Then began the search for the light (not merely in the sense of light captured from extra –terrestrial object but also from perspective of enlightenment on any practical project endeavor). The project, that had initially been driven by the Hope that there shall be light, finally completed with perseverance and desire (stronger form of hope) of team members that there will definitely be light.

“Is there going to be just a timer circuit design that will control the exposure time of your web-camera?” Pandit madam tried to sum up Rahul’s interpretation on a project offered to us by TIFR. I was pondering, completely dumbfounded, what would Rahul answer for I barely knew what business we shall be put into if we accept this project. After all it was truly a question of much hyped BE Project, perhaps the only mandatory technical project activity that we, Bombay University Students do! Should you accept the rudimentary idea just for the TIFR’s name sake or the project is truly worth deep exploration and some concrete work? The project feasibility activity was to start at this dilemma!

The Project was to check the feasibility of a low cost CMOS Sensor based Web-camera for the purpose of taking Astronomical Images. The key reason for TIFR to offer this project to us was that the exposure time for capturing the frames with such cameras was believed to be electronically controllable and we were keen to experimentation in electronics. Web-cam is a device that typically captures 10-30 frames per second and with the help of a computer overlaps those to give a feel of live motion video. We were to lessen the captured frame rate to one frame per second or so, thus enabling us to have a longer exposure time for astronomical imaging. This web-camera when modified and mounted on a telescope should function as an imaging device, requiring a computer to complete the whole set-up. With minimum set up of a telescope, a computer and the modified web-camera, an amateur observatory could be set up at any school/academic institute. Rahul, with his zeal about astronomy had Astronomical perspectives about what could be the breakthrough if we succeed achieving this glittering goal of capturing planets with a Web-cam.

The first project meet with TIFR Project guide lasted for half an hour; I could barely comprehend the discussion between Rahul and our project guide. Right in the second meet we got the low-cost web camera and Rahul started his investigation on details of ICs used therein. It would have been late August by then and I was busy with DISHA 2004. In the mean while he had investigated enough to convince ourselves of a forthcoming activity worthwhile enough to be called a BE Project. Then struck the first shock! The IC details for the sensor and the driver were nowhere to be found. Neither did my project guide have it nor did the manufacturers respond to our solemn plead. We tried soliciting some IIT Professors’ aid but there was no light to be seen! We made analyses as to which camera to buy and for ‘To be Determined and To Do’ and deferred the project till Semester Eight.

Then began the camera hunt! Our rummaging at Electronics Markets at Andheri, Dadar and Lamington Road proved just Nomad’s wandering. The camera with the required details was not to be found at any market in Mumbai. The suggestion to buy it online came but it would kill the basic purpose of the project…a low cost easily available web camera to put to use! Time, being easily measurable entity of any project, had elapsed to an extent that we felt we will complete this project by eternity; we decided to go ahead with a web-camera whose product label matched with that of an intended one! But lady luck had something different in store for us. The ICs (sensor and driver chips) were altogether different and though we could decipher some of the driver chip details, the pin layout was not available. The concept of using a timer circuit to control the exposure time will have to be abandoned with the acquired device, as it would not be appropriate to fiddle with the driver IC arbitrarily.

We had just recovered from the shock from Scope Change; we geared up for the first acquisition. My project guide had put the telescope at World Trade Centre Tower, Colaba to see if the camera can capture a terrestrial object through a telescope. We graduated to an object of astronomical interest, Jupiter and he focused the telescope at the Jupiter that has just arisen at horizon. Our eyes glued fixedly at the screen…and aghast…there was absolutely nothing in the very first acquisition. Absolutely nothing but the random Gaussian noise! Our hope felled miserably in the darkness that was right in front of us. Will there be any light to our project? The next day I approached our Project Guide, Prachi Madam to report the first failure, but she alleviated our disturbed composure saying,” You would then prove how such a device can not prove useful in astronomical imaging, your aim is first to check feasibility!”. Pandit madam too added ‘To prove certain things do not work certain way can be a subject of exploration for PhD Theses’.

The web-camera has a converging lens placed right above the sensor and this lens focuses the rays from distant objects on to the lens. When we had placed the camera at the eyepiece of telescope, the image was not getting formed on the sensor, so we thought of removing this lens. We gathered the leftover confidence and geared up for the second acquisition. The earth’s rotation above itself makes the focused image of any object to move when you keep the telescope stationary. The malfunctioning tracking system of telescope had even made the matter worse to focus any object. But this adverse situation is ideally the one which you would expect with a low cost telescope and low cost camera. If you go in for low cost camera, then you certainly cannot afford a 3-motor based tracking system. My Project Guide, Mr. Anand Ghaisas, with his ingenious expertise at handling telescope focused at Moon and I clicked away a frame. Prachi madam asked us to go ahead with offline image processing algorithms as we had resolved to the said scope change.

The moon would always be the largest object that you can capture, so even if there is no tracking system you can easily go ahead with it. But that’s the most primary astronomical object. We graduated to Jupiter and Saturn. With no tracking system I truly realized we are engaged in so to say ‘Wild goose chase’. The image would just fleet away in a fraction of second, before my glued eyes could realize the object was in field. With the right fielding of Anand Ghaisas, Rahul, Prasanna at telescope and me with eyes glued at screen with eagerness as much as those in draught-struck farmers’ eyes glued at the skies; we had some more acquisitions.

We had been trying our hand at Matlab and coding the IP algorithms of Gonzales. Still we were passing sleepless nights (Not only because we were to go to TIFR at night but also the problems to number a few). The ad-hoc arrangement of somehow holding the camera for acquisition should not do, so we sketched the mounting arrangement and gave it to workshop at TIFR. It then stalled the acquisitions for about a month. It was March by then and we did not have significant acquisitions yet! Hazy, cloudy skies were one more hurdle and to be precise two of our trips to TIFR had been futile on this account. In the mean while we got the control system ready for acquisitions. Then we acquired the stacked images of Jupiter, Saturn and Orion. We could later carry out offline integration (long exposure effect by adding image frames) in Matlab using algorithm. It eliminates the need of a tracking system. We had to stop acquisitions as per the time frame of project. The next activity was Image Processing that ran for last two months, making me fond of Gonzales. There was some light finally to our project endeavours.

At the close of the project I still had some questions unanswered as a result of deep deliberation. To name a few were: In Astronomy they make use of optical filters. Can you simulate the effect of optical filter digitally? Can you completely justify the transformed images as information sources for physical details of objects e.g. Is the measured size of a crater in a transformed image true or pseudo?

I’m glad to know that there will be a fresh batch of students that will try to throw light on some of these undiscovered areas of this research project.

The project perhaps taught us there would be many questions yet to be answered with any mundane activity you carry out. We should ask these ‘WH’ questions ourselves and work to find out the answers. The same thoughts (inductive, deductive and reductive) have been given to us by our forebears of discipline of science to ask questions. I did appreciate the statement ‘Science has progressed on realization of knowledge of the past is inadequate to answer all the questions’.

0 Comments:

Post a Comment

<< Home