This course consists of four laboratory experiments that concentrate on radio instrumentation and laboratory techniques. We will build receiving, observing, and data analysis systems for two telescopes: a single-dish 21-cm line system, and a 10.7-GHz interferometer. We will use these telescopes for astronomical observing projects including structure of the Milky Way galaxy, precise position measurement of several radio sources, and measurement of the radio brightness distributions of the sun and moon with high angular resolution. There is a heavy emphasis on digital data acquisition, software development in the Python language, and high-quality written reports.

Topics by Date

Lab 1 (Exploring Digital Sampling, Fourier Transforms, and both DSB and SSB Mixers), Due Feb 12, 2:00p

Lab 1, Week 2 (Jan 29): DSB and SSB Mixers

• Theory and Background:
• Demos and Tutorials
• In class:
• Lecture: Fourier Transforms, Convolution Theorem, Data Types
• Show and Tell (10m per group)
• Scientific Python Review (numpy, pylab, scipy)
• Python Installation and Basic Programming, second pass
• Lecture: Introduction to DSB and SSB Mixers

Lab 2 (Astronomy with the 21cm Line; Some Microwave Electronics), due Mar 5, 2:00p

Lab 2, Week 1 (Feb 12): 21cm Line and Waveguides

• Theory and Background:
• Demos and Tutorials
• In class:
• Introduction to Horn and Receiver
• Time
• Doppler Corrections, ugradio.doppler

Lab 2, Week 2 (Feb 19): Collect and Analyze Data

• Theory and Background
• Demos and Tutorials
• Matrix Math with Numpy
• In Class:
• Show and Tell
• Waveguides, Transmission Lines, and Rope
• Fitting Gaussians and Polynomials, ugradio.gauss

Lab 3 (Radio Interferometry at X Band), due Apr 9, 2:00p

Lab 3 Week 1 (Mar 5): Interferometer

• Theory and Background
• In Class:
• Tour of Rooftop Interferometer
• Exercise Ball Coordinates
• Interferometry with Strings

Lab 3 Week 2 (Mar 12): Collect and Analyze Data

• Theory and Background
• In Class:
• Show and Tell
• Controlling the Telescope
• Tracking the Sun
• Scheduling Observations

Lab 3 Week 3 (Mar 19): Collect and Analyze Data

• Theory and Background
• In Class:
• Show and Tell
• Linear Least-Squares in Python
• Minimizing Chi-Square
• Noise in Observations

Lab 3 Week 4 (Apr 2): Write Lab Report

• Theory and Background
• In Class:
• Show and Tell
• Photon bucket demo
• Lab 3 Due Apr 9, 2:00p

Lab 4 (Mapping the HI Line: the Galaxy and Supershells), due May 7, 2:00p

Lab 4 Week 1 (Apr 9): Leuschner Dish

• Theory and Background
• In Class:
• Trip to Leuschner: Class will go later than usual
• drive mechanism (how the dish moves)
• feed (notice probes) and cables
• IF setup (one channel for OH, one for HI)
• show spectrum
• demo action
• spatial sampling with dish

Lab 4 Week 2 (Apr 16): Collect and Analyze Data

• Theory and Background
• In Class:
• Show and Tell
• pointing control
• how to take data
• computing doppler width for a line of sight (assuming circular motion)

Lab 4 Week 3 (Apr 23): Collect and Analyze Data

• Theory and Background
• In Class:
• Show and Tell
• close-out plan
• calibrating spectra
• converting spectra to hydrogen