Advanced Monocular Passive Ranging (A-MPR) for HALO-II

The Phase-I investigation resulted in a major breakthough in terms of algorithmic capabilities to retrieve thrusting target range using passive measurements of target spectral radiation. Range, range uncertainty, and range sensitivity are computed with high accuracy. The algorithm takes full advantage of the atmospheric propagation models (e.g., Modtran), while the inputs to the model are also retrieved from the radiation measurements. The algorithm was demonstrated with numerous synthetic data cases as well as with actual sensor measurements (Black Brant launch from White Sands Missile Range). The technique, based on an inverse problem solution, was demonstrated to work with different types of sensors including multispectral (such as the HALO-II system equipped with appropriate bandpass filters) or hyperspectral sensors with a large number of bands. It was also shown that multiple bands improve algorithm accuracy and make the approach less sensitive to sensor noise. For a hyperspectral sensor, it was shown that noise had negligible impact on range retrieval accuracy. Under Phase-II, efforts will focus on porting the algorithm to a flight capable system and integrating the system on board the HALO-II aircraft. This work will be accomplished with the full support of Aeromet, the developer and operator of the HALO-II system. In parallel to the hardware implementation, the algorithm will be further tested with plume radiation measurements of several target vehicles types (solids, amines, and cryogenic) through a wide range of trajectory parameters. Additional enhancements will be implemented to reduce overall uncertainty, and to account for correlated parameters.