Far Field Imaging
Far Field Imaging - Related Videos
14:25
Determining 3D Flow Fields via Multi-camera Light Field Imaging
0 Views •
Cited by 7 •
2013
A technique for performing quantitative three-dimensional (3D) imaging for a range of fluid flows is presented. Using concepts from the area of Light Field Imaging, we reconstruct 3D volumes from arrays of images. Our 3D results span a broad range including velocity fields and multi-phase bubble size distributions.
12:27
Assembly, Tuning and Use of an Apertureless Near Field Infrared Microscope for Protein Imaging
0 Views •
Cited by 3 •
2009
The assembly of a nearfield infrared microscope for imaging protein aggregates is described.
10:50
Functional Imaging of Auditory Cortex in Adult Cats using High-field fMRI
0 Views •
Cited by 6 •
2014
Functional studies of the auditory system in mammals have traditionally been conducted using spatially-focused techniques such as electrophysiological recordings. The following protocol describes a method of visualizing large-scale patterns of evoked hemodynamic activity in the cat auditory cortex using functional magnetic resonance imaging.
06:42
Wide-field Fluorescent Microscopy and Fluorescent Imaging Flow Cytometry on a Cell-phone
0 Views •
Cited by 32 •
2013
We review our recent results on the integration of fluorescent microscopy and imaging flow cytometry tools on a cell-phone using compact and cost-effective opto-fluidic attachments. These cell-phone based micro-analysis devices might be useful for cytometric analysis, such as performing various cell counting tasks as well as for high-throughput screening of e.g., water samples in resource limited settings.
FAQs
Propagation beyond the near-field region allows the recorded pattern to represent the angular distribution of propagating waves. A lens or detector therefore measures how wave energy is distributed with direction rather than capturing only a local field pattern. This relationship helps engineers connect measured image features with the object’s spatial-frequency content and evaluate whether the observation meets far-field conditions.
Diffraction limits which spatial-frequency components can be distinguished in the recorded image. Fine object details correspond to higher spatial frequencies, so the available diffraction pattern determines whether those details remain separable. Engineers use this relationship to assess resolution and to guide optical system designs intended to produce more detailed measurements.
In coherent systems, the waves maintain phase relationships, so the recorded result depends on both wave amplitude and the way components interfere. Two measurements with related intensity distributions can therefore differ when their phase relationships change. Accounting for phase and interference is important when engineers interpret coherent images or characterize optical behavior from the observed pattern.
A practical setup must provide propagation beyond the near-field region and include a lens or detector capable of recording the angular distribution of the waves. Engineers then examine the resulting pattern in relation to diffraction and spatial-frequency content. These conditions determine whether the measurement represents the intended far-field behavior and supports meaningful resolution analysis.
The approach supports microscopy, remote sensing, astronomy, antenna characterization, and optical system testing. In each case, the recorded angular distribution provides information about how an object or system produces propagating waves. This makes the technique useful for measuring distant or wave-based phenomena and for comparing observed performance with the behavior expected from an engineered system.
Engineers interpret diffraction-limited patterns and spatial-frequency information to identify what an optical system can resolve. The results reveal whether the measurement captures the desired object detail and whether propagation conditions are appropriate. Such analysis informs the development of higher-resolution imaging systems and provides a basis for testing the performance of existing optical designs.