Analysis of Through-Wall, Lens-less Imaging Technique

The ultimate goal of this project is to research and analyze a through-wall, lens-less imaging technique. It is known to be "active" in the sense that "illumination" energy is projected into an area to elicit a return signal, from which images are reconstructed. Because this goal is so nebulous and future courses of action dependent on intermediate results, it's anticipated that multiple iterations and studies will be required.

A well-defined and specific, initial objective is to identify and characterize the "illumination" energy (IE). This is almost certainly an electromagnetic signal or signals of some sort. Although this project is supposed to concentrate on the IE, the nature of the imaging information and how it is elicited by the IE is an integral part of the overall process which cannot be ignored and should be accounted for. This returned signal could well be different than a reflection of the IE, as this does not appear to be a radar technique.

Some information is already known about the IE from direct observations, including the ability to penetrate metal walls, slightly ionize air, and transfer substantial momentum to objects. Other are known, derived from actions based on the content in the obtained images. More context and a detailed summary of the current state of knowledge and underlying rationale is available here: https://www.surveillancenation.us/lnslimag/files/Lens-less%20Imaging.pdf (This link is valid but the site is under construction.) This essay also describes the special circumstances that have to be accommodated, such as lack of control over the illumination energy, and low probability of intercept, low probability of detection (LPI/LPD) tactics.

As a first step, a set of potential candidates for the illumination energy that are consistent with the observations in the essay need to be generated, along with experimental methods that could be used to directly identify the signal by detection and recording. The essay contains a number of detailed observations, but properties of the IE that seem salient and that will constrain the possibilities are as follows:
1) The IE causes a slight ionization of air as well as fluorescence of certain materials.
2) The IE has the ability to transfer momentum well beyond that intrinsic to photons (their radiation pressure).
3) The IE can penetrate metal walls.
4) The absorption of small amounts of visible light in the presence of the IE may constitute a sampling of the visible light present in an area.
5) All these effects can be focused into specific volumes well within enclosed buildings, using equipment entirely external to the building.

The first milestone is to generate a detailed report that identifies physical processes that are candidates. For each such candidate, an explanation of how each of these observations are explained by known physical principles, and how it generates imaging information.

The second milestone is to outline experimental methods that could distinguish amongst the candidate hypotheses that are proposed, and simple methods of replicating the known effects of the IE in test situations. The proposal should be detailed enough to include the necessary classes of equipment, e.g. RF versus photonic, for different situations, but a more detailed protocol is probably best reserved for a subsequent project.

My best estimate of the skills needed encompass applied electromagnetics, radio frequency, spectrum analysis, photonics, and experimental physics. This is very much an applied area where knowledge of tricks of the trade and special cases are important, as well as practical knowledge of real-world implementations.

Given the exploratory nature of this project, I understand that intermediate results may shape future directions. While the first milestone focuses on identifying potential candidates for the illumination energy and explaining their alignment with observations, I am open to iterative discussions and adjustments as new insights emerge. The second milestone will build on these findings, with flexibility to refine experimental methods collaboratively.