Apparatus and Setup
This capstone lab requires students to write a short, quantitatively justified instrument or observing proposal synthesizing at least three of the preceding six labs' tools (resolution, sampling, SNR/exposure time, calibration, spectral resolving power, or Strehl ratio) for a self-chosen, instructor-approved real science scenario, following Lecture 14's proposal-design framework.
Materials and Data
| Quantity | Value |
|---|---|
| Keck exposure time for SNR=100 on the V=18 worked scenario | 0 s |
| Equivalent VLT-class (8.2 m) exposure time for the same SNR | 0 s |
| Total photometric error budget for the 300 s Keck scenario | 10.44 mmag (Poisson 0.13, flat-field 3.0, extinction 10.0) |
Procedure
- State a specific, one-sentence science requirement for a self-chosen real science scenario (e.g., detecting a specific magnitude change, resolving a specific angular separation, or measuring a specific radial-velocity amplitude).
- Using at least three of this course's quantitative tools (Rayleigh criterion, plate scale/Nyquist sampling, CCD SNR equation, calibration/zero point, grating equation/resolving power, or Strehl ratio), work backward from the science requirement to a specific telescope, instrument configuration, and exposure time or observing strategy.
- Construct an explicit root-sum-square error budget (Lecture 13) for the proposed measurement, naming every relevant error term and identifying the dominant one.
- Using the worked Keck-versus-VLT-class exposure-time comparison in the data table as a model, compare at least two credible telescope/instrument alternatives for your proposal, and justify your final recommendation quantitatively rather than by assertion.
Analysis and Uncertainty
Explicitly state which of this proposal's inputs are live-verified real data, which are standard published values not independently re-verified this session, and which are simplifying assumptions (e.g., a representative rather than site-specific sky brightness or throughput), following this course's tri-level provenance standard.
Deliverables
- A one-paragraph science requirement statement.
- A quantitative technical justification connecting that requirement to a specific telescope, instrument, and exposure time, using at least three of this course's tools.
- An explicit RSS error budget with the dominant term identified.
- A two-alternative trade-space comparison with a justified final recommendation.
Assessment Criteria
- Clear, specific, one-sentence science requirement.
- Correct, internally consistent use of at least three course tools to justify the proposed configuration.
- Correctly constructed RSS error budget with a correctly identified dominant term.
- Quantitatively (not qualitatively) justified trade-space recommendation.
References and Provenance
- OpenStax Astronomy 2e (local reference copy: references/openstax-astronomy-2e-extracted.txt), Chapter 6 (astronomical instruments), descriptive only; this course exceeds that introductory treatment throughout.
- All quantities in the data table are computed programmatically in
materials/ASTR340/src/generate_astr340_content.pyfrom this course's established real and standard-published datasets; seematerials/ASTR340/reference-log.md. - Generated by
materials/ASTR340/src/generate_astr340_labs_psets.py.