Unit Planner: Imaging
Unit: Imaging
Start date:
Diploma assessment
Paper 1
Paper 2
Paper 3 x
Investigation x
Text book reference
Hamper - online resources
Inquiry: Establishing the purpose of the unit
Transfer Goals
List here one to three big, overarching, long-term goals for this unit. Transfer goals are the major goals that ask students to “transfer”, or apply, their knowledge, skills, and concepts at the end of the unit under new/different circumstances, and on their own without scaffolding from the teacher.
- To know the definitions of objects, images and wavefronts
- To understand the qualitative and quantitative functions of lenses, microscopes and telescopes
- To be able to explain the applications of imaging for communications and medicine
Content
List here the key content that students will know by the end of the unit
Imaging
- Thin lenses
- Converging and diverging lenses
- Converging and diverging mirrors
- Real and virtual images
Instrumentation
- Optical compound microscopes
- Simple optical astronomical refracting telescopes
- Simple optical astronomical reflecting telescopes
- Single-dish radio telescopes
- Radio interferometry telescopes
- Satellite-borne telescopes
Fibre optics
- Structure of optic fibres
- Attenuation and the decibel (dB) scale
Medical imaging
- Detection and recording of X-ray images in medical contexts
- Generation and detection of ultrasound in medical contexts
- Medical imaging techniques (magnetic resonance imaging) involving nuclear magnetic resonance (NMR)
Skills
List here the key skills that students will develop by the end of the unit.
Imaging
- Describing how a curved transparent interface modifies the shape of an incident wavefront
- Identifying the principal axis, focal point and focal length of a simple converging or diverging lens on a scaled diagram
- Solving problems involving not more than two lenses by constructing scaled ray diagrams
- Solving problems involving not more than two curved mirrors by constructing scaled ray diagrams
- Solving problems involving the thin lens equation, linear magnification and angular magnification
Instrumentation
- Constructing and interpreting ray diagrams of optical compound microscopes at normal adjustment
- Solving problems involving the angular magnification and resolution of optical compound microscopes
- Constructing or completing ray diagrams of simple optical astronomical refracting telescopes at normal adjustment
- Solving problems involving the angular magnification of simple optical astronomical telescopes
Fibre optics
- Solving problems involving total internal reflection and critical angle in the context of fibre optics
- Solving problems involving attenuation
Medical imaging
- Explaining features of X-ray imaging, including attenuation coefficient, half-value thickness, linear/mass absorption coefficients and techniques for improvements of sharpness and contrast
- Solving X-ray attenuation problems
- Solving problems involving ultrasound acoustic impedance, speed of ultrasound through tissue and air and relative intensity levels
Concepts
List here the key concepts that students will understand by the end of the unit
Imaging
- Ray diagrams
- Linear and angular magnification
- Spherical and chromatic aberrations
Instrumentation
- Optical compound microscopes
- Simple optical astronomical refracting telescopes
- Simple optical astronomical reflecting telescopes
- Single-dish radio telescopes
- Radio interferometry telescopes
- Satellite-borne telescopes
Fibre optics
- Step-index fibres and graded-index fibres
- Total internal reflection and critical angle
- Waveguide and material dispersion in optic fibres
Medical imaging
- Detection and recording of X-ray images in medical contexts
- Generation and detection of ultrasound in medical contexts
- Medical imaging techniques (magnetic resonance imaging) involving nuclear magnetic resonance (NMR)
Applications
Examples of real world practical applications of knowledge.
- Explaining spherical and chromatic aberrations and describing ways to reduce their effects on images
- Investigating the optical compound microscope experimentally
- Investigating the performance of a simple optical astronomical refracting telescope experimentally
- Describing the comparative performance of Earth-based telescopes and satellite-borne telescopes
- Describing how waveguide and material dispersion can lead to attenuation and how this can be accounted for
- Describing the advantages of fibre optics over twisted pair and coaxial cables
- Explaining features of medical ultrasound techniques, including choice of frequency, use of gel and the difference between A and B scans
- Explaining the use of gradient fields in NMR
- Explaining the origin of the relaxation of proton spin and consequent emission of signal in NMR
- Discussing the advantages and disadvantages of ultrasound and NMR scanning methods, including a simple assessment of risk in these medical procedures
Action: teaching and learning through Inquiry
Approaches to teaching
Tick boxes to indicate pedagogical approaches used.
Simulation x
Small group work (pairs) x
Hands on practical x
Video x
TOK
Examples of how TOK can be introduced in this unit
- This topic has governing laws with disputes over ownership, e.g. Snell's Law
- It is useful to make approximations to aid understanding e.g. ray diagrams rather than wavefronts
- There are applications of Imaging theory beyond the traditional Group 4 scientific disciplines - what about archaeology, medicine, engineering, astronomy and film?
- Some of the equations in this topic can be derived using geometry
- If we are sufficiently clear, we can state rules that will be true in any optical device
- Cost vs benefit analysis is good practice when deciding whether or not to employ a particular intervention
NOS
Examples of how NOS can be introduced in this unit.
- There is no denying that the real-world relevance of Imaging is sky-high
- Is it important for today's youth to practise pencil and paper drawing skills when computer-assisted design is so prominent in industry?
- We can use models for the eye and for telescopes, but still have a firm understanding of their function and mechanisms. Ever tried to construct an eye in Algodoo?
- The 2018 Nobel Prize for Physics was awarded to Arthur Ashkin, Gérard Mourou and Donna Strickland for groundbreaking inventions in the field of laser physics.
Assessments
Tests, exams and marked labs
Formative assessment opportunities have been included throughout the Activity worksheets. Summative assessment can be practised by attempting Paper 3.
Worksheets and exercises
Resources
Video clips, simulations demonstrations etc.
All resources required are detailed throughout the Activity worksheets.
Reflections
What went well
List the portions of the unit (content, assessment, planning) that were successful
What didn’t work well
List the portions of the unit (content, assessment, planning) that were not as successful as hoped
Notes/changes/suggestions:
List any notes, suggestions, or considerations for the future teaching of this unit.