DOD STTR 24.A BAA

Active
No
Status
Closed
Release Date
November 29th, 2023
Open Date
January 3rd, 2024
Due Date(s)
February 21st, 2024
Close Date
February 21st, 2024
Topic No.
SF24A-T005

Topic

High Throughput Visible-Wavelength Multispectral Filter Arrays via Spectral Multiplexing

Agency

Department of DefenseN/A

Program

Type: STTRPhase: Phase IYear: 2024

Summary

The Department of Defense (DOD) is seeking proposals for a Small Business Innovation Research (SBIR) Phase I project titled "High Throughput Visible-Wavelength Multispectral Filter Arrays via Spectral Multiplexing". The objective of this project is to design and fabricate a multiplexing multispectral filter array that achieves a higher optical throughput than a narrowband array with equivalent bandwidth and spectral resolution. Current visible-wavelength multispectral filter array technologies suffer from low light throughput, limiting the ability to capture high spectral resolution hyperspectral video. To address this issue, the performer will design and fabricate a visible-wavelength multiplexing multispectral filter array that is sensitive to multiple wavelengths at once. The fabricated array will be mounted onto a monochromatic camera to demonstrate scene sampling and demosaicking. Success will be measured by comparing the signal-to-noise ratio, integration time, and spectral resolution and bandwidth to those of an off-the-shelf narrowband multispectral filter array. The project will be conducted in three phases. In Phase I, modeling and simulation will be performed to determine the recipe for depositing the multiplexing filter array onto glass. Facilities for filter array fabrication will be identified. In Phase II, the filter array will be fabricated and characterized. Hyperspectral measurements will be acquired and compared to imagery from an off-the-shelf pushbroom hyperspectral camera. The Phase II deliverable will be the fabricated filter array attached to the provided sensor. In Phase III, the spatial and spectral resolution of the camera with the filter array will be characterized, and a mounting system will be built for the camera to be attached to a drone. A field test will be performed to acquire hyperspectral video of moving ground targets. The project falls under the OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Space Technology. The technology is restricted under the International Traffic in Arms Regulation (ITAR) or the Export Administration Regulation (EAR). Offerors must disclose any proposed use of foreign nationals and comply with US Export Control Laws. For more information and to submit a proposal, visit the solicitation agency's website: link. The application due date is February 21, 2024.

Description

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Space Technology

 

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

 

OBJECTIVE: To design and fabricate a multiplexing multispectral filter array covering the visible wavelengths that achieves a higher optical throughput than a narrowband array with equivalent bandwidth and spectral resolution.

 

DESCRIPTION: Describe the work you would like to see accomplished to meet the objective stated above. Character limit 25,000.

 

NOTE: Please do not write any Acronyms in the Topic Description. Spell out everything. Also no mathematical symbols.

 

To design and fabricate a multiplexing multispectral filter array covering the visible wavelengths that

achieves a higher optical throughput than a narrowband array with equivalent bandwidth and

spectral resolution.

 

Current visible-wavelength multispectral filter array technologies suffer from low light throughput because every pixel on the sensor only measures a single wavelength at a single spatial location. Multiple pixels are then considered together to construct the spectral signature over that group of pixels. This approach, while intuitive, leads to low light levels as the spectral resolution increases, since each pixel sees an ever-smaller piece of the object spectrum. The result of this is that high spectral resolution hyperspectral video becomes difficult due to the high integration times necessary to measure the signal. To resolve this issue, the performer will design and fabricate a visible-wavelength multiplexing multispectral filter array, where each filter is sensitive to many wavelengths at once. The performer will then mount their fabricated array onto an off-the-shelf monochromatic camera and demonstrate scene sampling and demosaicking. Success will be defined by the SNR, integration time, and spectral resolution and bandwidth compared to those of an off-the-shelf narrowband multispectral filter array.

 

PHASE I: Modeling and simulation will be performed to determine a recipe for depositing a multiplexing filter array onto glass. The simulated filter transmission spectra will be used to model the sampling and demosaicking of a standard hyperspectral test image. Facilities for filter array fabrication will be identified by the performer.

 

PHASE II: The multispectral filter array will be fabricated using the facilities identified by the performer during the Phase I. The performer will then characterize the array and align and mount it to a calibrated sensor. Hyperspectral measurements will then be acquired by the camera, demosaicked to recover the hyperspectral datacube, and then compared to imagery of the same scene acquired with an off-the-shelf pushbroom hyperspectral camera. The Phase II deliverable will be the fabricated filter array attached to the provided sensor.

 

PHASE III DUAL USE APPLICATIONS: The spatial and spectral resolution of a camera with the affixed filter array will be characterized. A mounting system will be built for the camera to allow it to be attached to an off-the-shelf drone. A field test will be performed in which hyperspectral video of multiple moving ground targets with diverse spectral content will be acquired from a drone.

 

REFERENCES:

Harwitt, M. and Sloane, N., "Hadamard Transform Optics," Academic Press, 1979;
Oliver, J. et al., “Filters with random transmittance for improving resolution in filter-array-based spectrometers,” Opt. Expr., 21(4), 2013;
Bian et al., "A low-cost integrated hyperspectral imaging sensor with full temporal and spatial resolution at VIS-NIR wide range," arXiv, arXiv:2306.11583v1, 2023.;

 

KEYWORDS: Multispectral Filter Array; Multiplexing Optics; Hyperspectral Imaging; Remote Sensing;

Optical Filter Fabrication; Optical Coatings