The late Professor Meghnad Saha with his foresight saw the relevance and importance of positional astronomy in India. It was his inspiration that led to the formation of a Nautical Almanac Unit, under the aegis of the India Meteorological Department in Alipore, Calcutta, on December 1, 1955.
The Planning Committee set up by the Government of India had recommended in 1955 the preparation of an Astronomical Ephemeris and Nautical Almanac for the development of astronomical and astrophysical studies in India. The Calendar Reform Committee formed in 1952 under the Council of Scientific and Industrial Research ( CSIR) of the Government of India with the late Prof. M.N. Saha as chairman, recommended the preparation of the Indian Ephemeris and Nautical Almanac incorporating therein, along with the usual astronomical data, the National Calendar of India (the Saka Calendar) with timings of tithis (dates), nakshatras and yoga calculated with modern astronomical formulae and also with festival dates. It was decided that the work should be done by a special unit attached to a scientific department of the Government of India. Subsequently the residual work of the Calendar Reform Committee and also the preparation of the Indian Ephemeris and Nautical Almanac was taken up from CSIR by the India Meteorological Department on December 1, 1955. The unit which was functioning as the office of the Calendar Reform Committee at the then Institute of Nuclear Physics, Calcutta, was attached to the Regional Meteorological Centre, Calcutta, as one of its sections named as Nautical Almanac Unit.
The late Prof. Saha was aware of the works of the late N.C. Lahiri in the field of astronomy and Calendar Reform. In 1952 he called Lahiri to help him in the work of the Calendar Reform Committee as its member-secretary. After completion of the Calendar CommitteeÕs work, Lahiri was entrusted with the work of the Nautical Almanac Unit of the India Meteorological Department as its first officer-in-charge. The unit undertook the preparation of The Indian Ephemeris and Nautical Almanac for 1958 which was the first issue published in March, 1957. The Nautical Almanac Unit was initially located in the office premises of the Regional Meteorological Centre at Alipore, Calcutta. The foundation work of the Nautical Almanac Unit was appropriately streamlined by the late N.C. Lahiri. On LahiriÕs retirement from Government service in February, 1970 A. Bandyopadhyay took charge of the Nautical Almanac Unit.
The final scheme on development of the Nautical Almanac Unit under the Fifth Five Year Plan was approved in 1976 and due to expansion of the unit it was found difficult to accommodate the entire Nautical Almanac Unit in the office premises of the R.M.C. at Alipore and, consequently, a building at New Alipore was hired. On January 1, 1977, the Nautical Almanac Unit with all its staff and officers was shifted to the present location at New Alipore.
The Nautical Almanac Unit was earlier under the administrative control of the then Director, Regional Meteorological Centre, Calcutta. In 1976 a high power Committee was constituted under the Chairmanship of Dr. R. Ramanna to review the organisational structure and functions of the India Meteorological Department. The Ramanna Committee after examination of the working of the Nautical Almanac Unit recommended its independent status and also upgrading of the post of officer-in-charge of the Unit to the level of Director. These recommendations were finally approved by the Council of Meteorology and Atmospheric Sciences (CMAS) of the Government of India and it was decided that the Nautical Almanac Unit would be completely separated from the administrative control of the Director, Regional Meteorological Centre, Calcutta. It was made an independent centre to be known as Positional Astronomy Centre (P.A.C.) directly under the control of the Director General of Meteorology, New Delhi. The CMAS also recommended an Advisory Committee consisting of a few experts in this particular field of astronomy to guide the development work of the Centre. The Positional Astronomy Centre was formally inaugurated on April 26, 1980.
The Centre mainly publishes astronomical books. The Nautical Almanac Unit compiled the first issue of Indian Ephemeris and Nautical Almanac for 1958 . From the issue for 1979 the title of this publication was changed to Indian Astronomical Ephemeris. This publication contains advance positions of the sun, moon, planets, stars and details of eclipses and occultation with particular reference to India and its neighbouring countries. It contains a section of Indian National Calendar giving all astronomical data required for the preparation of a Panchang and also for festivals of different communities in India. The Government of India and other State Governments mainly depend upon this publication for declaring holidays.
India is one of the eight countries of the world to prepare and publish such an astronomical ephemeris. The other countries are U.K., U.S.A., Russia, France, Spain, Japan and China. Apart from Japan and China, India is the only country in Asia to publish an Ephemeris of its own. The neighbouring countries depend on this publication for their astronomical data as their requirements are like that of the Indian astronomers and Panchang-makers.
Tables of Sunrise, Sunset and Moonrise, Moonset is another publication of the Centre which is in considerable demand by various Government departments, especially the Army, the Air Force and other public concerns and newspapers.
At the instance of the Ministry of Home Affairs the Rashtriya Panchang using the Saka era is also being published by this Centre. Its main objective is to unify the divergent practices existing in different parts of the country and to promote a scientific basis for calendric computations. The first issue for the year 1897 SE (1957-58 AD) was published in June 1957. It is issued in 13 languages, namely English, Hindi, Sanskrit, Urdu, Assamese, Bengali, Oriya, Telugu, Tamil, Malayalam, Kannada, Marathi and Gujarati.
The publicity and sale of the Panchang has considerably increased and the people are being gradually convinced about its utility on an all-India basis and its correct calculations of tithi, nakshatra and other items necessary for Panchang-makers of our country. From 1922 SE(2000-2001 AD) one more edition , i.e. Punjabi in Gurumukhi script is being introduced.(PIB)
Director, Positional Astronomy Centre, Calcutta.