Archive for the ‘General’ Category

This happened few weeks before. But i am putting  it down here so that I can read it in future and smile.

I received an email from someone (Let’s say Mr. ABC working at amazon). Now the mail was as given below (recreated!):

I am contacting you to check if you would be interested in working with Amazon Hyderabad for a Software Development Engineer. Kindly respond back to -: to take this forward.

To which I replied that I would be interested in internship and forwarded my CV.

Now, few FAQs:

1) How did they reach me? : “Frankly speaking I don’t know. Someone said that HRs usually scroll linkedin and contact people with good profile. This could be the reason, but am not sure about it. Even both HRs, ABC and XYZ are not connected to me anyway. Not even in linkedin. I regularly maintain my linkedin profile, which u can check at:

2) Why did they contact me ? : “Call it exaggerated but, after seeing my work experience they thought am already graduated. So, that means they may approach me again next year. Ahem Ahem… even I can refer few people now “

Moving further, After weeks of my respond, they finally called me and scheduled my written test.( I thought it was for INTERNSHIP.) It was a coding test. I was given three questions and total time was about 1.5 hours. It was on Interview Street only. No objectives type questions. Two of them were solved using DP while the third one was relatively easy. After written, I had series of telephonic interviews (all technical). Interviewer asked me even to code on collabedit. Collabedit is a site that allows collaborative editing. So, any change I make in my doc appeared on his computer also.

Now, about the questions, Amazon usually repeat their questions every year. So, it is always good if you check few blogs to see previous year questions (which I did only for my last interview). My written was completely different! Their favorite topics for interview are binary trees and binary search trees. My first interview was only about BT and BST. I gave 4 different algo to check if a BT is BST.

The person who takes technical interview is not generally from HR department (Obvious!). He might belong to the department for which you are about to be selected. Apparently, I cleared all the rounds.

Quick tips:

1) Study Data structures. At-least you should know all definitions. I did not know that in BST equality always appear with the left child. My interviewer told this to me.

2) Interviewer gives time to think. But do not ever take too much time to answer.

After that! I guess most of my friends wanted to know what happened finally. For them, don’t worry am still unemployed. Now the craziest thing which no  one knows is that on the day of my last telephonic conversation, i received another “similar looking mail” from Amazon asking if i would like to work with them. The only difference is that this time it was from Amazon BANGALORE!

Currently we are using canon G10 for image acquisition. Obviously the decision of using it was good enough. Canon stopped manufacturing G10 even before we selected that camera. To make things (the Machine Vision code especially) better, I thought to change certain things. Now when the airframe is being restructured, I am thinking to change the camera. If the size, weight and obviously the budget allows I can think over to shift to a DSLR. Selecting an appropriate camera is important because if the acquired image is not good enough then obviously the image processing code will lead to false or no results.
So to select camera, I first short listed few cameras. I first prepared the list of cameras that may be given special attention because they have already been used for similar purpose like ours by some other people. Secondly I searched for all cameras that are supported by gphoto2 library (Canon G10 is one of them). Thousands of cameras were listed in this list. Then I started eliminating all point and shoot cameras. Obviously my aim was to select the best DSLR with in our budget that satisfies all our requirements. I already have been using a point and shoot camera (G10) that apparently satisfies our entire requirements. So now to make significant improvement in the image I need to consider the difference in a point and shoot and DSLR cameras. Moreover due to weight, economical and quality constrains I was made to focus only on Nikon and Canon cameras. This is how I shortlisted my long list of cameras. Obviously I knew what all parameters I am looking for within these cameras.

Cameras are framing systems which acquire a near-instantaneous “snapshot” of an area (A), of the surface. Camera systems are passive optical sensors that use a lens (B) (or system of lenses collectively referred to as the optics) to form an image at the focal plane (C), the plane at which an image is sharply defined.

For efficient processing I need a detailed image of the ground. The ground coverage of a photo depends on several factors, including the focal length of the lens, the platform altitude, and the format and size of the film. The focal length effectively controls the angular field of view of the lens and determines the area “seen” by the camera. The longer the focal length, the smaller the area covered on the ground, but with greater detail (i.e. Larger scale). Since the plane is moving with high speed, I need to find the optimum focal length so that I do not miss any land in continuous images and image still remains detailed as much possible. A zoom lens of focal 18-55mm with APS-C camera was found appropriate.

The area covered also depends on the altitude of the platform. At high altitudes, a camera will “see” a larger area on the ground than at lower altitudes, but with reduced detail (i.e. Smaller scale). In my case altitude may vary from 100 ft to 700 ft.
Also I need a fairly good shutter speed so that there is almost 10-50 percent land overlaps in my consecutive images. Using G10 now delivers one image in almost 3 seconds. Moreover I need very fast shutter speeds in order to combat the movement and vibrations of the aircraft. I can achieve these speeds with a combination of wide aperture and ISO. While there are many ways to set the camera, my suggestion is using Aperture Priority mode. Setting the aperture to one of the widest settings allows plenty of light into the camera. Depth-of-field is not an issue since most everything will be focused at infinity.
Depending on the brightness of the day, I start with the ISO at 100 or 200 and check the shutter speeds that are achieved with that aperture / ISO combination. If the shutter speed is below the range, I raise the ISO until it is in that range.


Posted: December 10, 2012 in General
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Aarush X1 is the result of an industry-academia collaboration between Lockheed Martin and
Delhi Technological University. The Unmanned Aerial System has been designed and fabricated
by a group of undergraduate students of the university, who received timely guidance from
mentors in the faculty and Lockheed Martin. The UAS has been designed according to the
constraints imposed by urban environments, making the system invaluable for ISR in cities like
Delhi and Mumbai. The system, in fact, can be modified to adapt to specific mission-dependent
Aarush X1

The UAS was unveiled by Dr. V.K.Saraswat, Director General, D.R.D.O, on November 2nd,
2012, at the Lokarpan Ceremony held at the India Habitat Centre. The ceremony was presided
over by Dr. D.N. Reddy (title), and Dr.R.P.Aggarwal. The event witnessed a small presentation
by the student project manger and team captain, outlining the design and fabrication process
adopted by the team. Mr. John Sheehan, who along with Dr. Peter Drewes, mentored the students,
highlighted the key accomplishments of the project, and congratulated the students on their
acheivement.Mr. Abhay Paranjape, (title) also attended the ceremomy, and emphasised on the
importance of the sustenance of student effort, and long term relationships between industry and
academia , in his talk.

Dr. V.K.Saraswat lauded the student effort and expressed a desire to nurture the student talent. He
also outlined some major capabilities that are demanded of current Unmanned Air Systems, like
stealth and payload compatibility.The Lokarpan Ceremony was also attended by representatives
from HAL, NTRO, Army, IAF and DST.

The ceremony concluded with an invitation to all the attendees to witness the First Public Flight
of Aarush-X1, which was to be held the following day (November 3rd) at Karnal Institute of
Civil Aviation, Haryana.

The Flight Day was attended by engineers from HAL and NTRO amongst others.
The UAS did a single sortie for about 3 minutes. Telemetry and real time video, were displayed
at the portable ground station. The UAS was taxied to the viewing area, after the landing, for a
visual inspection by the attendees, which was followed by a question and answer session.

Courtesy: Bhavya N. Gupta

Being a-part (UAS-DTU)

Posted: July 9, 2012 in General, Work
Tags: , , ,

UAS-DTU is a project undertaken by B.Tech. Students in Delhi Technological University.

The DTU UAS project was initiated with the primary purpose of developing technologies so as to reduce India’s dependance on foreign ISR (Intelligence, Surveillance and Reconnaisance) products.

The project aims to:
– Maximize in-house research and development
– Minimize the usage of Commercial Off The Shelf products so as to keep the costs low.
– Develop UAVs with reliabilty and safety as their core USPs.

The team participates in the AUVSI Student UAS Competition (an international inter-university aerial robotics challenge) which is held annualy in Webster Field, Maryland, USA


This was all i read about it when i just entered into the college and was not a part of this project. But soon i can to knew about my interest in Image Processing and I thank Harsh Agrawal sir (one of the team member) who made me know my interest. So, when the team started recruitment in August I too applied. The recruitment process was really good and I really admire it. After passing the written exam i went under series of interview. And to my strange in one of the interview I was even asked to play Portal game (to check my skills). My last interview was a 7 hour interview started at 12 noon till & p.m.

I was determined throughout. And yeah !! i got selected.

So, I entered the team as Software Developer, Image Processing.

Since that day, I have learned a lot be it about image processing or may many other aspects of life. Working under the finest Leader Jayant Malani was an immense pleasure to me. Seeing the greatest minds like Kumar Shaurya Shankar acted like lots of inspiration to me. Resp. Shivang Baveja  taught me the definition of dedication.

I feel that am writing late about UAS  but there is never too late for good stuff.

Working in team does not only increase my technical skills but also management. Everyone’s dedication in the team, spending sleepless nights in Lab working, standing for hours in sun for test flights , has ultimately brought  us 3rd position in SUAS this year.Thanks to all people supporting us in anyway.

But along with work we do have lots of fun

I have many more things to say, but feel I could only say that for UAS DTU Sky is just the beginning .

Finally my first post as a Microsoft Student Partner.

It was in November 2011, when I was selected as a Microsoft Student Partner. Frankly, initially being unknown to the benefits and opportunities that MSP programs brings with it, I was first less involved in this program.

But it was the Microsoft which made me realize what powers I have as a developer. MSP program  gives me lots of opportunities to learn and platforms to test my skills. And even we get interact with technical people around the globe. And we even get goodies

As a MSP till now I have conducted various technical sessions majority of them being on Windows Phone 7. Its was this MSP program that drag me towards windows phone 7 app development. Windows Phone App development excited me because I could develop apps quickly and easily. Once i developed about three apps in a day  . And when you get a chance to win Nokia Lumia  800 for free why wont you develop apps ??

Yoo, I got Nokia Lumia 800 for free from Microsoft by simply developing for small apps in IUnlockJoy event 🙂

It would be unjust with this show stopper if don’ t upload its pic. So here i go…..

talking about the phone excites me, and so here I go speechless

Controlling my emotions

the very  first day with this phone i found few things Microsoft Should look upon

1) Vibration with Ringtone – cummon Nokia 1100 even have it  ….

2)  Sending file with bluetooth  forget it

3) You cant mark different things like images together

4) I felt it more of like Iphone architecture….

5. can we sync doc files without internet …oh damm i guess no

6) alarm did not rise me up when i switched off my phone

7) finally we have copy (cut ??)

8) text selection is very poor

but still I am loving my phone 🙂

Apart from this learning, conducting sessions and organizing events like Dream Spark Yatra with fellow MSPs brings lots of fun.

Not boosting much opportunities we get as MSP, I will say: BE IT AND HAVE IT.