Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Title
S A Ananthakrishnan - Session 01
Identifier
OH-002-29-1
Digital Object URI
Description
(0:00) Parents, childhood, and college years
Subramaniam Ananthakrishnan was born in Tamil Nadu. He mentions his ancestral family’s migration to Trivandrum. His father studied at Banaras Hindu University and worked for the Government of India as an engineer. He was brought up in erstwhile Tranvancore state and later Tamil Nadu and he went to Calcutta for his college education, first at St Xavier’s College, then at Presidency College, and his Master’s at the Institute of Radio Physics and Electronics.
He recounts how he got the Jagadish Bose National Talent Scholarship and a medal from Jawaharlal Nehru in the presence of Indira Gandhi.
Ananthakrishnan recounts that his university professors encouraged him to apply to TIFR as Govind Swarup had begun a radio astronomy group there. He speaks about how he received the ‘Visiting membership’ to study at TIFR. He mentions two other friends from Calcutta who also got selected for TIFR, including one who later went to work in nuclear physics in the US and another who became a dean at IIT Bombay.
(06:10) Time at TIFR and building Ooty Radio Telescope in the 1970s.
Ananthakrishnan joined TIFR in 1966 and was mentored by NVG Sarma and MN Joshi (both of whom worked with Govind Swarup in Delhi), who recommended to Ananthakrishnan that he join the team building the Ooty Radio Telescope and help in developing the electronics for the multi-Ooty radio telescope. He recounts that they made the electronics in 2 to 3 years in a lab at TIFR.
They took their first recording with the telescope in 1970. He recounts the group dynamics among the scientists and students during the building of ORT. He mentions that the team also built the dipole array system.
In 1971, a major accident occurred at the telescope due to a mechanical failure, causing one part of the telescope to collapse and twist. He, Balasubramanian, and Swarup repaired the telescope and got it working again after two years, by 1973 September.
He recounts the uniqueness of the ORT project and the work that has been done using the ORT.
(15:38) Proposal of the Giant Equatorial Radio Telescope.
Ananthakrishnan discusses Swarup’s new project ideas post ORT. Swarup wanted to extend the ORT with further small cylindrical parabolic cylinders to increase the collecting area of the main telescope. This was called the Ooty Synthesis Radio Telescope (OSRT).
The telescope was receiving only a fixed frequency of 326.5 megahertz and a little bit of adjacent bands, and the main research area was lunar occultation and interplanetary scintillation and Pulsars.
Swarup proposed building a 2-kilometer-long radio telescope on the equator to be the largest ever built, which Swarup called the Giant Equatorial Radio Telescope (GERT).
He recounts why Ooty was chosen as the site to build the radio telescope.
A proposal was made to build the GERT telescope in Kenya or Indonesia, but it didn't work out due to various reasons. Ananthakrishnan recounts why the idea of the GERT was difficult, due to logistics and as well as due to the death of the then-President of Kenya, Jomo Kenyatta. They had to give up on the project by 1982.
After the building of the ORT, Ananthakrishnan stayed back to operate the telescope and later went for a postdoctoral fellowship from 1977 to 1979.
(00:22:53) Conceiving of the Giant Metrewave Radio Telescope (GMRT)
He recounts that there was a need for a bigger telescope. He mentions his idea to create several telescopes in different geographical locations and use a method called Very Long Baseline Interferometry for a new telescope. Another colleague, Durga Bagri proposed the idea of a Large Metrewave Array. Both ideas were deemed unfeasible.
Swarup comes up with the idea of a "poor man's Very Large Array". Ananthakrishnan recounts that this idea was proposed on the day after a New Year's Eve party where the members of the Ooty radio telescope were present. This idea was converted into a proposal and sent to the TIFR director and then to the Atomic Energy Commission. After long discussions and consultations with radio astronomers at other institutes, the project was deemed feasible. Ananthakrishnan recounts the then director of the AEC asking Swarup, who was now 58, who would lead the project in case of his absence. Swarup said that the scientists who built ORT would also work on this new radio telescope.
(00:29:30) Finding a location for the GMRT
Ananthakrishnan discusses challenges in finding suitable locations for low-frequency telescopes due to cost constraints and a nationalistic approach. He speaks about the decision to build a low-frequency radio telescope as opposed to a high-frequency radio telescope. Equipment to build a low-frequency telescope would cost less.
The team first considered near North Bangalore where the Gauribidanur radio telescope was present. But, physicists from the ionospheric physics community raised several concerns about the site.
Ananthakrishnan recounts that they searched for a site across several states in India. They initially considered a site near Indore as AEC had the Center of Advance Technology, Indore, and they could offer land. However, there were scientific constraints with the land. The area also lacked talent and lack of technological development for a telescope. A town near Indore named Mhow (Military Headquarters of War) had communications equipment that created a lot of radio frequency interference.
He mentions that Prof Pramesh Rao suggested north of Pune as a possibility. Ananthakrishnan used the Survey of India maps to survey the sites, including the Pune location. He mentions that there is a Vikram Earth Station near Narayangoan which was a possibility and another site south of Pune near Dhondh. They identified the area around Narayangaon. He mentions that the engineers at the Vikram Earth Station were willing to provide support.
(00:39: 57) Acquiring land in Pune for GMRT
He mentions that there is a Vikram Earth Station near Narayangoan which was a possibility and another site south of Pune near Dhondh. They identified the area around Narangaon. He mentions that the engineers at the Vikram Earth Station were willing to provide support.
He mentions that they met the Collector and Commissioner of Pune and explained the project. Mr. Rane, the then Commissioner of Pune, was very supportive. Ananthakrishnan describes the land where they decided to build the GMRT.
Between 1985 and 1987, they began to acquire the land. Ananthakrishnan spoke to the village residents, many of whom were Project Affected People (PAP) who were moved there from other dam projects. Farmers on that land were required to donate their land. Ananthakrishnan recounts that an engineer, N V Nagarathinam, helped a lot in acquiring the sites.
(00:45:34-00:45:49) Interruption
(00:45:50) Resume
As Ananthakrishnan worked to acquire land, the proposal for the project went to the Government of India for approval.
(00:46:27) The design of the telescopes for GMRT
1985, the International Astronomical Union held a congress in New Delhi. Here, Ananthakrishnan along with Swarup and other colleagues set up a meeting with international radio astronomers to discuss GMRT. They advised against building parabolic cylinders and instead built parabolic dishes.
Parabolic dishes are more expensive to build. Govind proposed using parabolic arms and connecting them with turn buckles to create a dish. This allowed the dish to be low-cost and easy to assemble. They built a prototype GMRT dish in Ooty.
Ananthakrishnan recalls additional challenges with mounting the dish and constructing the antennae. The brainstorming happened in Bangalore, where some of the team had shifted.
(00:54:34) Cost and team of GMRT
The Tata Consulting Engineers were involved both in building the ORT and GMRT, as well as scientists from the ORT team. Ananthakrishnan was in charge of acquiring land and was the head of the electronics and opines why he became head. He was the project scientist for 10 years, from 1988 to 1998.
The cost increased from when the project was first proposed to when it was finally executed in 1995. The price increase was due to oil embargoes and conflict in the Middle East. Ananthakrishnan estimates that the cost was 60 crores by 1995.
The group of engineers and admin shifted from Ooty and Bangalore to Pune. Only the skeletal group remained in Ooty. This led to the creation of NCRA, while NCBS was being created.
(00:59:31) Reasons for pursuing physics in college
Ananthakrishnan discusses his interest in physics through experiments, despite his initial interest in chemistry. He recounts difficulty remembering organic formulas contributing to his decision. He went to Presidency College since it was the best college.
His decision to pursue radio science and electronics was informed by a group of friends in college and their influence on his decision to pursue radio astronomy Physics. He recounts that they collectively decided to join the radio physics department at Calcutta University. He recounts finding astronomy fascinating since childhood and his father teaching him the constellations.
Ananthakrishnan mentions his work as a radio astronomer and says that he prefers to be called a radio scientist since his work has also included electronics and engineering.
Ananthakrishnan reflects on his MTech degree and its usefulness in his work as well as the importance of a degree in one’s career.
(01:10:30 ) The development and challenges of the Giant Metre Wave Radio Telescope (GMRT).
Ananthakrishnan reflects on the challenges of building GMRT. He recounts Swarup’s concern about the completion of the project. By 1994, Ananthakrishnan felt more confident that the project could be completed as many of the electronics components had been successfully built. For the project, engineers and technical staff were hired for the GMRT project, with a focus on recruitment from across India.
There were two challenges that Ananthakrishnan recounted. The antennas had to work simultaneously, and operations had to be synchronized. And the correlator needed to be working.
By 2000, the GMRT team had made significant progress in observing and studying various astrophysical sources, including galaxies, quasars, and pulsars.
Ananthakrishnan reflects on the teamwork and synergy between team members as a key component for GMRT’s success. He opines the conditions required for projects such as GMRT to be a success such as freedom, which he says TIFR offers to its scientists.
(1:21:47) Running the GMRT
He speaks about the branded identity of GMRT. GMRT is now involved in new projects like the Square Kilometre Array, which he is a part of.
Ananthakrishnan highlights India's growth in radio astronomy, from unknown to eminence. He mentions the projects he has been involved in, including a 3.6-meter telescope and a 21-meter Cherenkov experiment telescope, and helped troubleshoot issues with a stratospheric tropospheric radar.
(01:29:13) Indigenous scientific instrument development in India.
Ananthakrishnan highlights the benefits of in-house facility development for long-term efficiency and control. He advocates for more large-scale science projects in India to develop domestic competence in technology and assembly. Gives complete control over instruments. Need more large-scale projects in India to develop competence.
Scientists and engineers in GMRT worked together, but as the project grew, they had to divide responsibilities more clearly for efficient collaboration.
(1:34:05) Team structure and synergy in a large telescope project.
The group building the ORT was small and the scientists were also engineers, so control was in the scientist's hands, reflects Ananthakrishnan. He contrasts the ORT team structure with that of GMRT, which was a large project. He asserts that for a large project such as GMRT to be successful, it requires the scientists to have a good understanding of engineers, as well as clearly defined roles. GMRT had the advantage of a group of engineers from the TIFR and Tata Consulting Engineers who had worked on ORT and thus had a good relationship with one another.
He recounts that the Tata Consulting Engineers were also involved in building the ARVI dish under the guidance of Swarup around 1966. Design engineer Suresh Tapde, who worked later on GMRT also worked on the ARVI project in 1967.
(01:43:06) ORT accident, GERT, and division of research groups.
Ananthakrishnan recounts the ORT accident. The group found out late in the night. The accident occurred due to a differential motion between parts of the telescope. He explains that the accident might have been a result of overuse of the telescope without time for maintenance. He and V Balasubramanian went up that night and took precautionary measures.
He then describes shutting down the GERT program. He recounts an argument with Swarup and says that the group did not wish to colonize other countries with radio astronomy and wished to do a project within India.
Ananthakrishnan recounts that TIFR was not in favour of partitioning TIFR. Swarup argued that the GMRT group was too large to be controlled from the Mumbai TIFR campus. TIFR was concerned about inbreeding and the benefits of a large institution under one umbrella.
(01:55:46) TIFR radio astronomy group during and after ORT, formation of NCRA
Between 1968 and 1969, most of the TIFR radio astronomy group moved to Ooty. Swarup shifted to Ooty in 1974. The Ooty group had become self-sufficient. He mentions V R Venugopal and how Venugopal was well-connected in Ooty which made it easy for the group to get work done.
Ananthakrishnan recounts an interaction with a group of parliamentarians, three of whom were Jyoti Basu, Atal Bihari Vajpayee, and Piloo Mody. The parliamentarians had come to see the telescope.
Ananthakrishnan was the only member of the ORT group’s scientists who was transferred to Pune at the behest of Swarup. His children did part of their education in Pune. He recounts how NCRA and IUCAA were given the land by the Vice Chancellor of Pune University. IUCAA became a reality due to Prof. Yash Pal who was the UGC chairman at the time.
In 1989, with the housing society complete within 13 months, many more members moved to Pune from Ooty, Bangalore, and Bombay. He mentions part of the group of scientists who worked on ORT moved back to Bombay after the completion of ORT.
[2:01:15 - 2:01:55 – Restricted Access. Contact archives@ncbs.res.in for details]
(02:08:13) On the Electronics Department at Pune University
Prof Kholaskar invited Ananthakrishnan to join the electronic science department at Pune University as an Adjunct Professor, teaching and conducting research there for 13 years. The department nominated Ananthakrishnan to the Raja Ramanna Research Fellowship, and he was elected to various science academies in the 1994-2004 period. He then became an INSA senior scientist. Since 2017, he has been an INSA honorary scientist, for which he got a grant to run contingencies in the department for 5 years.
Ananthakrishnan began a communication lab in the Electronic department in 2008 and received 70 lakhs from ISRO for this. He recounts the benefits of the lab in the department.
(02:17:10) Space antenna and student projects.
In 2010, he had a collaboration with Sweden. He talks about the Swedish proposal to Ananthakrishnan to put antennas on the moon, and the proposal's outcome. He talks about the search for funds for the antennas' prototyping and the project's progress. He mentions that students carried out the project.
He also mentions a proposal to the Indian Oceanographic Expedition to put the antenna payload in the Arctic to collect data in the Arctic night.
Date(s)
Collection
Oral History: History of Science