IAO 2006, Практически тур, Група α, английски — Задача 7. Antennae GMRT.

Practical round. Problems to solve · 10 ноември 2006 г.

Source annotations

In problem 6 the printed “radial” is crossed out and replaced by handwritten “rotational”. The handwritten antenna list A1, A10, A14, A30 is included. The Russian alternate crosses out 7.3; the English edition does not, so its printed 7.3 is retained.

Условие

A table with coordinates of the GMRT antennae as relative positions from the central antenna A14 is given below. The latitude and longitude of A14 are $\varphi=19^\circ05'36''$, $\lambda=74^\circ03'01''$.

7.1. Prepare the map of the GMRT antennae system. You need to mark the central square on the map (the 1 km × 1 km area, which you saw during your GMRT visit), mark antenna at the origin and plot all the antennae outside the central square. Write down the antenna number near its location on the graph paper.

Parallel beams of radio-waves come from distant objects and falls on the GMRT antenna. The signals will reach different antennas at slightly different times depending on the inclination of the source with respect to the Antenna. Let us assume that the four antennas listed below are observing Sun at noon 23rd September: A1, A10, A14, A30.

7.2. Calculate the delay in signal arrival between A1 and the Antenna farthest from A1, assuming a flat Earth.

7.3. Assuming now the Earth is not flat, calculate the additional term in time lag due to curvature of the Earth.

Решение

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Оригинал в Архива: alphapract.jpg · допълнителни данни: alphapractdata.jpg