OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Directed Energy; Hypersonics; Advanced Infrastructure & Advanced Manufacturing 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: Develop an innovative model of low- and high-altitude atmospheric effects on the ultraviolet (UV), visible (Vis), and infrared (IR) observables of hypersonic configurations that includes, but is not limited to, non-local thermodynamic equilibrium (NLTE) effects to support the detection of dim, fast-moving targets by observing assets employing unconventional viewing geometries. DESCRIPTION: In order to exploit more observable properties of hypersonic configurations, a separate topic is proposed to undertake the task of expanding relevant predictive tools into the ultraviolet (UV) and visible (Vis) regimes of the electromagnetic spectrum. However, these observables and their contrast against various backgrounds (i.e., black space, earth limb, terrain, sea, clouds) are modified by atmospheric effects when being viewed by observing assets. In addition, challenging viewing conditions for a number of missile defense missions are driving needs for novel sensing solutions such as constellations of remote sensing satellites [1] or limb-viewing un-crewed aerial vehicles. Among the most pressing needs is the enhanced detection and tracking of dim targets such as hypersonic cruise missiles viewed against an Earth background. The already small target signal can be obscured by a varied and cluttered natural environment which will include, but is not limited to, the effects of atmospheric attenuation, non-local thermodynamic equilibrium (NLTE) earth limb radiation, aurora, and cloud background effects. Further complications arise when utilizing off-nadir and limb viewing geometries resulting in: significantly greater impacts from refraction, non-uniform ground surface distances on the focal plane, and the significant increase in dynamic range due to the Earth background. To provide the desired capability, a high-fidelity atmospheric effects model is needed--one that includes, but is not limited to: the radiation transport solution between the sensor and the observed scene, the ability to model background environments at infrared-through-ultraviolet wavelengths, broken cloud fields, significant refractive effects at long ranges, and NLTE effects. Additionally, the solution must be traceable to current standard codes such as the Standardized All-Altitude Modulation Model (SAMM) [2] and the Standardized Atmosphere Generator (SAG) [3]. The model should enable the prediction of observed target contrast signatures for sensor systems and is expected to be used with scene generation tools such as the Fast Line-of-sight Imagery for Target and Exhaust-plume Signatures (FLITES) [4] code. PHASE I: Phase I-like proposals will not be evaluated and will be rejected as nonresponsive. For this topic, the Government expects the small business would have accomplished the following in a Phase I-like effort via some other means, e.g., independent research and development (IRAD) or other source, a concept for a workable prototype or design to address, at a minimum, the basic capabilities of the stated objective above. Proposal must show, as appropriate, a demonstrated technical feasibility or nascent capability. The documentation provided must substantiate the proposer's development of a preliminary understanding of the technology to be applied in their Phase II proposal in meeting topic objectives. Documentation should comprise all relevant information including, but not limited to, technical reports, test data, prototype designs/models, and performance goals/results. Feasibility = maturity and what have you already done/validated. Proposers interested in participating in Direct to Phase II must include in their responses to this topic Phase I feasibility documentation that substantiates the scientific and technical merit and Phase I feasibility described in Phase I above has been met. (i.e., the small business must have performed a proof of concept like Phase I component and/or other validation in a relevant environment, and/or at a much higher TRL level (5 or higher) and describe the potential commercialization applications. The documentation provided must validate that the proposer has completed development of technology in previous work or research completed.) IRAD work, previous Phase I/Phase II work: Documentation should include the most relevant information including, but not limited to: technical reports, test data, prototype designs/models, and/or performance goals/results. Work submitted within the feasibility documentation must have been substantially performed by the proposer and/or the principal investigator (PI). PHASE II: Develop and deliver the next-generation environment effects model with improved prototype atmospheric radiation transport capability based on current standard models such as SAMM and the proof of concept demonstrated by the Phase I evidence. As part of the Phase II effort, the small business should identify measured data which can be used to establish evidence of validation of the Phase II models under DoD-relevant conditions. In addition, the integration of the Phase II prototype software within the stakeholders' current simulation process, such as those using the Joint Navy-Army-NASA-Air Force (JANNAF) Exhaust Plume and Signature Subcommittee (EPSS) signature prediction suite [5], should be demonstrated for relevant missile defense scenarios of interest to the Missile Defense Agency. The prototype software should also demonstrate the capability to integrate with relevant scene generators such as FLITES. All software developed under this effort, including executable and source code, as well as associated databases, makefiles, and example case input/output files should be delivered during the course of contract performance to enable the Government to test the resulting prototype. The corresponding final software products and technical/user manuals should also be delivered to the Government. PHASE III DUAL USE APPLICATIONS: There are a number of government and private organizations that rely on ultraviolet, visible, and infrared atmospheric radiation and transmission models and simulations for defense purposes as well as non-defense, commercial remote sensing applications. Work performed under this effort will yield a modeling capability for high-fidelity defense and commercial applications requiring atmospheric characterization and forecasting, atmospheric correction, and remote sensing. REFERENCES: 1. Michael Luu and Daniel E. Hastings, Review of On-Orbit Servicing Considerations for Low-Earth Orbit Constellations, AIAA ASCEND 2021, paper AIAA 2021-4207; doi: 10.2514/6.2021-4207 2. Hoang Dothe, James W. Duff, John H. Gruninger, Prabhat K. Acharya, Alexander Berk, and James H. Brown, Users' Manual for SAMM 2, SHARC-4 and MODTRAN 4 MERGED, AFRL-VS-HA-TR-2004-1001 (2004). 3. Raphael Panfili, Hoang Dothe, John Gruninger, and James Duff, Characterizing temperature and water vapor of the environment using the standardized atmosphere generator (SAG) empirical model, Imaging Spectrometry XXII: Applications, Sensors, and Processing, SPIE 10768, 107680K (2018); doi: 10.1117/12.2321712 4. Crow, D., C. Coker, and W. Keen, Fast Line-of-sight Imagery for Target and Exhaust-plume Signatures (FLITES) Scene Generation Program, Proc. SPIE 6208, 62080J (2006); 5. Vaughn, M. E., Jr, The JANNAF Initiative: Plume/Wake/Hypersonic Flowfield and Hardbody Signature Prediction Capabilities for the Near Term, 39th JANNAF Exhaust Plume and Signatures Subcommittee Meeting, (2022). KEYWORDS: Atmospheric effects; backgrounds; contrast signature; remote sensing; non-Local Thermodynamic Equilibrium; non-LTE; infrared; visible; ultraviolet; simulation environments; SAG; SAMM; JANNAF; FLITES
