Description
Studies telescope optics, detectors, filters, spectrographs, adaptive optics, calibration systems, observatory operations, space-based instruments, error budgets, and instrument proposal design. ASTR 340 is the direct instrumentation-focused sequel to ASTR 210 (Observational Astronomy and Data Analysis): where ASTR 210 taught students to reduce and calibrate real CCD data, ASTR 340 derives the physical principles behind every stage of the observing chain that ASTR 210 treated more operationally — the diffraction limit and Rayleigh criterion, plate scale and pixel sampling, the CCD signal-to-noise equation, calibration-frame physics, the grating equation and spectral resolving power, adaptive-optics wavefront correction and the Strehl ratio, and radiometric error budgets — and applies each derivation to real telescope and instrument specifications (Keck, HST, VLT, JWST, and Keck's HIRES echelle spectrograph and adaptive optics system; see reference-log.md).
Learning Outcomes
- Describe the full astronomical observing chain from telescope aperture to calibrated scientific measurement, and explain the Cassegrain optical layout and the roles of aperture and effective focal length.
- Derive the Rayleigh criterion for diffraction-limited angular resolution from the Airy pattern, and distinguish diffraction-limited from seeing-limited ground-based imaging.
- Derive the plate-scale relation and apply the Nyquist sampling criterion to real telescope-detector combinations.
- Describe CCD detector physics (quantum efficiency, charge-coupled readout, gain, full well) and the three principal detector noise sources (shot noise, dark current, read noise).
- Derive and apply the CCD signal-to-noise equation to plan real exposure times, and perform a full bias/dark/flat calibration sequence with a photometric zero-point derivation from a real standard star.
- Derive the grating equation and spectral resolving power, describe the echelle-plus-cross-disperser design, and connect resolving power to radial-velocity measurement precision using Keck's HIRES spectrograph as a real worked example.
- Derive the Maréchal approximation relating residual wavefront error to Strehl ratio, and evaluate real adaptive-optics and space-telescope performance data against the diffraction limit.
- Construct a root-sum-square radiometric error budget and synthesize this course's full toolkit into a quantitatively justified instrument or observing proposal.
Textbook and Materials
Primary reading: OpenStax Astronomy 2e (free, openly licensed; local extracted reference copy under references/openstax-astronomy-2e-extracted.txt), Chapter 6 (astronomical instruments), which covers telescopes, detectors, and instrumentation only descriptively at an introductory level. Because ASTR 340 is an upper-division instrumentation course, nearly every quantitative topic (the Rayleigh criterion derivation, the plate-scale and Nyquist-sampling relations, CCD noise theory, the CCD signal-to-noise equation, the calibration equation, the grating equation and resolving power, the Maréchal approximation, and radiometric error budgets) is derived here from first principles and applied to real telescope and instrument specifications, well beyond OpenStax's introductory treatment; each affected lecture's slides and notes state this explicitly rather than presenting a derived result as OpenStax-sourced.
Assessment
| Component | Weight |
|---|---|
| Problem sets (7) | 30% |
| Labs (7) | 30% |
| Midterm exam (Lectures 1–7) | 15% |
| Final exam (cumulative, emphasis Lectures 8–14) | 20% |
| Participation and reading checks | 5% |
Lecture, Lab, and Problem-Set Cadence
The course runs 14 lectures, 7 labs, and 7 problem sets — a matched 1:1 biweekly cadence in which each lab and its paired problem set both follow the same two-lecture unit. This cadence directly follows the ASTR 230/ASTR 310/ASTR 330 precedent (a 3-credit, 14-lecture structure consistent with ASTR 320's own matched-cadence 3-credit course), because ASTR 340's seven thematic units each build one self-contained instrumentation skill — telescope optics and resolution, focal-plane geometry, detector architecture and noise, signal-to-noise planning and calibration, photometric systems and spectroscopy, adaptive optics and space instruments, and error budgets — that culminates in one capstone lab and problem set (Lab/PS 07, a full instrument-proposal synthesis) rather than requiring an uneven, project-report-style cadence. A matched cadence also lets each lab and problem set reinforce the immediately preceding lecture pair's derivation and real-instrument worked example while the mathematics is still fresh, exactly as justified for ASTR 230/ASTR 310/ASTR 330.
| Unit | Lectures | Lab | Problem Set | Topic |
|---|---|---|---|---|
| 1 | 1–2 | Lab 01 | PS 01 | Telescope optics, aperture, and the diffraction limit |
| 2 | 3–4 | Lab 02 | PS 02 | Focal-plane geometry and CCD detector architecture |
| 3 | 5–6 | Lab 03 | PS 03 | Detector noise and the CCD signal-to-noise equation |
| 4 | 7–8 | Lab 04 | PS 04 | Calibration frames and photometric filter systems |
| 5 | 9–10 | Lab 05 | PS 05 | The grating equation, resolving power, and echelle spectrographs |
| 6 | 11–12 | Lab 06 | PS 06 | Adaptive optics, the Strehl ratio, and space-based instruments |
| 7 | 13–14 | Lab 07 | PS 07 | Radiometric error budgets and capstone instrument proposal design |
Revision Policy
High standards apply to all graded work. Problem sets and labs may be revised and resubmitted once for improved credit within one week of return, provided the resubmission includes a short change note identifying what was corrected and why (see each problem set's assessment instructions for full criteria).
Prerequisites Check
ASTR 210 (Observational Astronomy and Data Analysis) supplies the operational foundation this course builds on: real CCD calibration workflows, basic signal-to-noise reasoning, and plate-solving/astrometric plate-scale concepts, all of which ASTR 340 revisits here at a derivational, first-principles level and extends to spectroscopy, adaptive optics, and error-budget analysis. PHYS 275 (Optics or equivalent upper-division physics) supplies the wave-optics background (diffraction, interference, Fourier concepts) needed to derive the Airy pattern and Rayleigh criterion (Lecture 02) and the grating equation (Lecture 09) from first principles rather than accepting them as given formulas.