Oven Controlled Crystal Oscillator MCOCXOW

I looked for crystal controlled COs. Here is one data sheet from Golledge. Excellent stability, we do not know the price. It is their featured product, from price and availability point of view.

AIPS : initial calib idea

Initial Calibration steps in AIPS

1. INDXR
   
2. First clip source for arbitrarily high points (100 KJy), due to correlator errors. (CLIPM)


3. SETJY to set fluxes of prim calib sources in SU table
   
4. CALIB on prim calib to find antenna solutions, SN tab 1
   
5. CALIB on second calib : SN tab 2
   
6. GETJY to calculate second calib fluxes to second calib (using SN and SU tables)
   
7. CLCAL apply second calib source calibration to target sources: CL tab 2
   

Now, one is free to excise interference. once one has cleaned all the data, return to step 4 above to redo the calibration process (after deleting all SN and CL tables generated above).

Is our PM senile?

One of Gandhi's letter goes on sale somewhere in the world, and some concerned 'Gandhians' wake up and write to the PM. Our ever-ready prime-minister orders Ministry of External Affairs to intervene to 'acquire' the letter from the Christie's.

Now, either those Gandhians have no better work to do than asking my poor country to pay up 10,000 pounds for a stupid piece of paper. Or PM has gone senile to provide so much of attention to some old, half-dead people. Or, perhaps I have too much time to ponder over such matter.

BUT, NO! It's my fu***ng tax money, and some oldies are looting it. They, by virtue of their age, do not pay any tax, if I remember correctly.


Update: India may serve a notice to Christie's, looks like the Law department has nothing much to do either. There are so many legal reforms pending, all we think of is one piece of paper...

fruitful day!

things done:

1. AIPS processing tutorial by Chiranjeevi, it has given a new perspective about GMRT interference removal and calibration.


2. ms for SAX 1808 paper is ready for desh's view.



3. there has been tons of discussion about radio telescope.
   
   
   • the 2-bit samples from 4 elements could combined in one byte per sample rate.
   
   
   • Cross-correlations of each two-element pairs (total 6 pairs, called 'baselines') can be done for N delays. Resultant array of N correlations can be passed over to FFT, resulting in amplitudes and phases for N/2 spectral channels. (This job can be simplified by using tabulated results for all 8-byte combinations).
   
   
   • The value N above is decided by delta-u and delta-v that we can have, using 1/imsize for our map (possibly 1/60 deg).
   
   
   • We need to keep computing such cross-correlations over a large time, integrating amplitude and phases over a large time (about 8 seconds or so).
   
   
   • These integrated amp and phases are the output (dynamic spectrum) of an effective software correlator.
   
   
   
   
   

BITS Goa Radio Telescope

when i spoke about our plans for hardware for our radio telescope, there was some feedback from my supervisor (Deshpande, RRI). he was of the opinion, that

1. our telescope was a fantastic idea, and could eventually do international science using 4 element dipoles. we have to plan and execute it well, of course.


2. in the beginning, we could make images using 2 antennas only, with Mandar and Aniket's data acquisition cards. this means, as soon as we demonstrate 2-slit interferometer, we can think of maps in the second semester.


3. we should think of using 2 bits and less bandwidth. eventually, we will have 4 element dipoles. so, we will have to store 4x2 = 8 bits = 1 byte at nyquist rate. if we opt for smaller bandwidth (0.25 MHz), we could be saving 0.5 MBytes per second on the disk, with each byte being a sample each from 4 elements.




In the immediate plans:



4. we should converge using "Mini Circuits" ICs for our RF components. See their website



5. also, for LO stability, either
   
   

   a) opt for GPS receiver, and use its 10 MHz signal for LO

   
   

   b) use a "oven controlled crystal oscillator"

   
   
   the second option is better for us for now. we will continue to explore the second option for better eventual stability of frequency signal. for better mapping, we need our sampler and LO to be really stable.
   
   

Freakonomics

I read the book Freakonomics. The book entertains and just gleams economic incentives in many daily issues (of largely American life). However, the best thing was the data about education gleamed from US schools, the incentives for cheating in high-stake exams. Thinking on that line, here are a few questions that arose in my mind:

1. What is the incentive for a student to join a school? Or, in other words, can we convince every parent and child to take education seriously, think long term, invest time and money in it?



2. What is the incentive for a bank or financial company to fund a student for his schooling? Can a micro-finance company find some benefits in spreading basic education in rural areas?



3. What is the reason that students sleep in my class? Or what incentive do they have in listening to me and to work harder on the course material?



4. What is the incentive that I keep myself in education? What would make me stop and move away from Goa?

The last one is a serious question too!

Adopt Your University ! Part 2

How to go about it?

I am elaborating a solution to remedy the mess in higher education, whereby a university is adopted by a local community, making the process very interactive, transparent, and responsible. I introduced in my earlier post the "Adopt Your University" campaign.

The basic idea: To adopt a university, and create a fund from the local community, council, city by `trading its shares', whereby common man buys those shares individually or through societies. The university is run from one-time fund and other running local funds. Then, local population will remain involved in deciding the content and direction of university programs.

Here we lay out ways to raise enough funds for the university from the public around, and involving the local community in growing and maintaining the university operations.

1. Create funds for the university by selling certain number of shares to the public. The shares are sold in such a way that no one person or group gets entire control of the shares. This will create a large amount, about 50 crores for the university. This will remain a one-time generation. In case of Shivaji University, Kolhapur district generates about 1000 crores each year, if my information is correct. A fraction of it is required here. People can trade these shares, under certain conditions. A part of the sales profit will go to the university.
   
   What do these shares mean to the public? It is similar the stock market companies in spirit. However, there are bound to be differences, for example, clearly there are no yearly dividends in cash or cheque.
   
   The shares will imply different things to different kind of people.
   
   For most, such as middle-class citizens, they would mean immediate benefits in the form of priority access to university facilities. These could include, but not limited to, astronomical observatory programs, auditorium lecture/demo programs, sports gymnasium and weight training, or discount in training fees for vocational courses (music, computers), etc.
   
   For farmers or small industrialists, it could mean priority access to different orientation programs, manpower training camps, or awareness campaigns. They could also mean, higher priority listing in receiving solutions of their queries/problems from the university.
   
   Any major change in University policy is explained in a general investors' meet (like Reliance Companies did). An approval is sought and then major decisions are taken to a vote.



2. Local community pledges support to the university by providing certain amount yearly. This will pay the salaries of the staff. This guarantees that the staff remains loyal to the cause and if the administration is lethargic, the city council could (in principle) stop their salary payments.


3. The research funding should come mainly from services to the local population, industry, including farmers. Some of it will also come from the central government grants, mainly for basic sciences.



4. The above conditions mean that
   
   • University remains committed to the local cause. Those programs which are not relevant for the community will not naturally receive any money. This is similar to ways of mother nature, where an organism has to evolve to remain relevant. University will keep transforming itself to grow.
   
   
   • Staff and administration will be responsive. If not, they will be unpopular in the local community, and the community can demand correction.
     
   • University is not subjected to large-scale politics. Since money is generated locally, it will not remain hostage to state/central government policies. The initial funds (50 Crores) will serve as a buffer if the local funds drop over a short period of time (5 years or so).
     
   
   
   
5. Programs of the university are decided by a committee of citizens. However, there is a danger in going local, one will certainly loose sight of global standards. Such issues of quality of university programs and maintaining standards is a major task.
   
   
   
   • The global focus is maintained through an expert senate committee with many outside experts in various fields. The committee, through independent enquiries, ascertains quality of university programs. It will also guide academic/research programs on campus...
   
   
   • There would be, in general, no fixed idea about having degree and doing a certain kind of work. Someone with BA (English) can dabble in other areas, if certain level can maintained. The pay scale will be less biased towards those with higher degrees.
   
   
   • Programs are implemented by administration adhering to global standards set by the committee, without any local interference. Rejection of political influence will be ensured by direct citizen support to the committee.
   
   
   
   
   
6. The operations could be decentralised. No one needs to come to university campus, one could log on the website and do many things. It will involve a generous use of radio network and computers to ensure quick communication and dissemination of knowledge to the community. One could use cheap and easy tools, such as campus radio station (by students perhaps?) or hand-held mobiles, with specialised programs developed for this need. With minimum training, volunteers & workers should be able to operate computer data bases, involving tools such as voice recognition and internet transfer of information from the central server to mobiles via SMS, etc.



7. The proposal keeps a lot of faith in committee running the university. This requires that the rule book is good, and the wo/men in charge must be honest and tough. They will be responsible for all the activity and retain all the rights and freedom to carry out every activity to perfection. This is possible, although expect political influences of all kinds. It is imperative that the local community is made aware about this issue and it has to support the persons-in-charge against any pressure.

In a future post I will outline one example, using Shivaji University from my hometown.

Adopt Your University !

A solution for higher-education crisis in India


Given terrible neglect of education sector in India, there is a serious concern about no viable education, and therefore competent jobs, for millions of deserving Indians, especially those who are dying to pay any fees for it.

The problem is, that we have heaped the entire responsibility of educating the populace on to a mythical entity called 'government'. In India it amounts to a large number of babus, arranged in a rigit vertical/horizontal structure. None of this structure was created for India's sake, but for usefulness of a certain Elizabeth. One of the best ways out to reform the university system is to again involve the local community in running the university.

Here is a solution, whereby a university is adopted by a local community, making the process very interactive, transparent, and responsible. I call this "Adopt Your University" campaign. In the current post I will outline the idea, details will be provided in the near future.

The basic idea: To adopt a university, and create a fund from the local community, council, city by `trading its shares', whereby common man buys those shares individually or through societies. The university is run from one-time fund and other running local funds. Then, local population will remain involved in deciding the content and direction of university programs.

Short background:

Apparently, Cambridge and Oxford universities were run by local townships through local funds. London came in the picture only in 19th century. Nalanda was sustained by Magadha kings, for the benefit of their population. Why can't present Indian universities be run like those, where local population sustains a university for their purpose and thereby gets more involved in its affairs. No one will look to government for funding, university will sustain itself by 'selling' its expertise and providing services to the community directly. It will justify its existence and underscore its relevance.

Goals:

1. University remains open to the public directly, through a Public Relation Office. Comments, complaints, request for advice and proposals are immediately attended to.
   
   

   University provides many services to the local community, such as:
   

   
   
   • Studies water harvesting strategies, rain-forecast based planning of crops, and tree plantation between farms and around.
   
   
   • Studies strategies in other farming practices about seeds, organic farming, bio-fertilisers, crop deceases, etc.
   
   
   • Studies local human/animal deceases, or pandemics (bird-flu or) and provides expertise to the community immediately.
   
   
   • Preserves knowledge about local history, ethnology, archeology, geology, zoology, botany is preserved and research conducted.
   
   
   • Promotes technology development for local community, such as agricultural tools (e.g., making of jaggery with improvisations in traditional methods) or industry solutions (e.g., cast iron technology and small, inexpensive improvements).
   
   
   • Promotes research in the local communities, to enable them to solve their own problems in innovative fashion. Any resultant local solutions could be marketed/patented (like GNU patent scheme) for the benefit of the community.
   
   
   • Promotes and preserves local arts and culture, through focussed efforts in those disciplines.
   
   
   
   
   
2. The university will be locally grounded, with local population and its needs. It is based on mutual need, for people can pay for information they need, and university personnel can earn a good living in turn.
   
   
   
   
   • Local human/animal deceases, or pandemics (bird-flu or) are studied and expertise provided to the community immediately.
   
   
   • Knowledge about local history, archeology, geology, zoology, botany is preserved and researched.
   
   
   • Promotes technology development for local community, such as agricultural tools (e.g., making of jaggery with improvisations in traditional methods) or industry solutions (e.g., cast iron technology and small, inexpensive improvements).
   
   
   
   • Promotes research in the local community, to enable them to solve their own problems in innovative fashion. Any resultant solutions could be marketed/patented (like GNU patent scheme) for the benefit of the community. This is modelled on the so-called "Barefoot College".
   
   
   
   • Promotes and preserves local arts and culture, through focussed efforts in those disciplines.
   
   
   
   
   
3. University will promote science and technology in the region.
   
   

   It will provide training and research foci for college and school teachers and students. It will also serve as knowledge center, where national and international experts can converge to interact with local scientists and engineers.




4. Although local issues get more prominence, they do not overshadow other research/training. Other disciplines, such as mathematics, psychology or business management will be pursued as well, however, with similar local bend.
   
   

   For example, the university could be involved in teacher's workshops, training other persons (laboratory technicians) from schools, who will avail this facility on payment of fees. Latest research in child/adolescent psychology and its links with education could be pursued, which will improve the grass-root education. Although this deserves an entire new thread on its own. Those who are interested should read Atanu Dey's posts on the topic of education.
   

   
   

Astronomy in Goa - V : Demands on Design.

Physical Needs

One student asked me for some comments about an Astronomy center in Goa. Here are my comments to her.

In my guide post I had outlined aims of the project and which communities would benefit from the exercise. Based on the answers to the first two, in my subsequent posts on this blog, I outlined activities that could be conducted for school, college and general audiences. Depending upon all these, we would know the physical, electro-mechanical, human and space needs of this project.

We will do this step by step: first work out physical and space needs of this projects. These are most crucial, for astronomy can not be done well from cities, even amateurs gain a world by being in remote, dark locations. No wonder our forefathers were fascinated by stars and we (those who live in light-polluting and claustrophobic cities) miss out on that wonder of stars and the Milky Way Galaxy!

Physical Needs:

Given that general public, students and teachers are going to observe the sky, the prime importance has to be given to an unhindered access to "dark sky" from all sides. Also, given that one would use academic tools, astronomy instruments and expects amateur crowds of variable numbers, it would desirable to split space into a number of smaller areas of variable sizes, which would be accessible to different populations at times desirable.

1. A well-connected set building which should host the following:
   
   
   • a library: with books in Konkani, Marathi, English. Books such as "Hubble Images" are needed for general audiences, whereas some elementary textbooks from Indira Gandhi Open University would be great for college students. Astronomy and science magazines and newsletters from around the world could be obtained and provided to the interested students.
   
   
   • Two display halls: poster exhibitions, astronomy and science-game rooms, general information displays (history, geography and ideas in Astronomy), introduction to historical figures, local communities and their small projects can be highlighted.
   
   
   • Three lecture rooms of variable sizes, say roughly 30, 80, 250, to allow for a large audiences in some interesting demonstrations or lectures. The display halls could doubled up as a lecture room of 200+ capacity, if built with appropriate scale in mind, they could be interconnected using video link, to allow even larger audiences. The lecture halls could be connected to the internet, allowing for video lectures, internet demonstrations, and virtual observations.
   
   
   • Demonstration labs for electronics and computers. Electronics laboratory would enable students to study, calibrate and use astronomy instruments. The computing laboratory is especially keeping in mind virtual observatory concept (remote observing and online content access).
   
   
   • Office space for visiting astronomers and lecturers: they could keep their belongings in these spaces, share material with support staff of the center, and keep a regular contact.
   
   
   • Observatory platform: space for a couple of telescopes. Ideally, one would like a single large telescope (16 inch) for serious amateur work, and perhaps four smaller telescopes for popular amateur demonstrations. The large telescope could be housed in the main building. To maintain light levels and low disturbance from crowds, perhaps this part could be a little away from remaining building.
   
   
   

   Given that a large population would use this building frequently, we need to special care about light levels around this building. Careful arrangement of parking, walking space, building interior lighting is required in order to minimise impact on local observers.

   
   
   
   
   
2. Open flat spaces: preferrably not green lawns, but higher from the ground to avoid stray animals entering. Perhaps we could use the terrace space over the above-mentioned lecture halls? We need to allow space for large crowd to sit outside and lean skywards to watch celestial events. We could build a terrace sloping gently (15 degrees?) towards south. This would align us towards to the Earth's axis, as we keep our feet towards the South. Stars would follow from left to the right. Given the slight tilt, it would be easier to watch the skys using a simple cushions.
   
   

   One would expect spaces with downward-facing lights, which will emit very little amount of light towards the sky and would be just enough for one to watch where they walk.
   

   Such flat spaces could be divided in multiple different locations, so that students, amateur astronomers, and general public can be segregated depending upon their needs of observations. All could use smaller (8 inch) telescopes and binoculars for their sky gazing.
   

   
   



3. Planetarium: A mobile planetarium could have a semi-permanent base in this center. It could visit various localities within Goa with a pre-planned (on demand) schedule.



4. Most importantly, we need to plant tall trees all around, so as to cover about 15 degrees altitude. This should cut down glows from large cities, it would also isolate us from oncoming traffic lights and any habitation disturbances. Trees such as jackfruits, Peepal and Neelgiri are good along with dense shrubs found in Goa. They grow fast, so no one needs to tend them much. We would avoid cash-crop trees, such mangoes, not only for obvious reasons, but also to save ourselves from animals, such as monkeys!

Average and the statistics of Poisson

Devan produced a lot of images using Poisson Statistics. But he could only see 20% frames with any photon at all. Why, can we not explain this using average number of photons from the sky?

Yes, we can. We get only average of 0.17 photon over all pixels of the detector put together. This gives a probability of ~84% to have zero photons incident on the detector. That is perfectly acceptable! Statistics can be trusted :p