MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: R

There are no items in this cart.
Continue Shopping
Menu
harsh mehta Grade: 12
        

Please explain what is astronomical interferometry?

7 years ago

Answers : (1)

shashank Saxena
13 Points
										

Astronomical Interferometry


The angular resolution that a telescope can achieve is determined by its diffraction limit (which is proportional to its diameter). The larger the telescope, the better its resolution. However, the cost of building a telescope also scales with its size. The purpose of astronomical interferometry is to achieve high-resolution observations using a cost-effective cluster of comparatively small telescopes rather than a single very expensive monolithic telescope. The basic unit of an astronomical interferometry is a pair of telescopes. Each pair of telescopes is a basic interferometer. Their position in u,v space is referred to as a baseline.



Early astronomical interferometry was involved with a single baseline being used to measure the amount of power on a particular small angular scale. Later astronomical interferometers were telescope arrays consisting of a set of telescopes, usually identical, arranged in a pattern on the ground. A limited number of baselines will result in insufficient coverage in u,v space. This can be alleviated by using the rotation of the Earth to rotate the array relative to the sky. This causes the points in u,v space that each baseline points at to change with time. Thus, a single baseline can measure information along a track in u,v space just by taking repeated measurements. This technique is called Earth-rotation synthesis. It is even possible to have a baseline of tens, hundreds, or even thousands of kilometers by using a technique called very long baseline interferometry.



The longer the wavelength of incoming radiation, the easier it is to measure its phase information. For this reason, early imaging interferometry was almost exclusively done with long wavelength radio telescopes. Examples of radio interferometers include the VLA and MERLIN. As the speed of correlators and associated technologies have improved, the minimum radiation wavelength observable by interferometry has decreased. There have been several submillimeter interferometers, with the largest, the Atacama Large Millimeter Array, currently under construction. Optical astronomical interferometers have traditionally been specialized instruments, but recent developments have broadened their capabilities.

7 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies
  • Complete Physics Course - Class 12
  • OFFERED PRICE: R 2,600
  • View Details
Get extra R 520 off
USE CODE: MOB20
  • Complete Physics Course - Class 11
  • OFFERED PRICE: R 2,800
  • View Details
Get extra R 560 off
USE CODE: MOB20

Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details