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OVERCAST Cloud Analysis and Processing TechCan

Analysis and forecast of visibility in the atmosphere remains a difficult scientific and operational problem. Current state-of-the-art model forecast capabilities are limited to basic derivations of cloud top height, liquid water content predictions, and potentially multiple cloud layers. Techniques vary widely from prognostic evaluation of cloud water properties and microphysics to simple evaluation of relative humidity. Similarly, near-real time satellite-based analysis imagery supports only limited cloud characteristic estimation such as cloud masking, heights, and temperatures. These minimal descriptors are not enough to describe intricacies of the local cloud environment, such cloud base heights or optical depths along slant paths.

This ONR Technical Candidate program is an applied research and technology demonstration/maturation effort to improve the state of global cloud analysis and forecasting. Scientific efforts under this thrust are aimed at leveraging existing tools, algorithms, and datasets to enhance and expand tools used to understand the four-dimensional evolution of the visibility of the atmosphere. This includes improved satellite remote sensing characterization and data fusion, nowcasting techniques, and improvements to numerical weather prediction model physics and/or post-processing.


The OVERCAST program seeks to improve the global analysis and forecast of atmospheric visibility. While the focus is on improved cloud analysis and forecasting, all aspects of applied research into improved atmospheric visibility will be considered and is not limited to the following examples. Characterization includes analysis of aerosols, particulates, and hydrometers in addition to all phases of water in the atmosphere (cloud ice, cloud liquid, and water vapor). Techniques may include traditional statistical categorization, advanced machine learning, model output post-processing, as well as development of new physics parametrizations, datasets, and methods. Work that improves understanding of opacity in the electro-optical to infrared wavelengths is preferred, but analysis of impacts on microwave and other electromagnetic wavelengths are welcomed. The main thrust areas will cover:

  • Develop and apply new algorithms and spectral capabilities from satellite based environmental monitoring, especially as python modules that can be run in near-real time from the Naval Research Laboratory (NRL) Geolocated Information Processing System (GeoIPS)
  • Observe evolving cloud character using remote sensing stereography, optical flow, and other novel techniques
  • Develop novel machine learning techniques to marry field observations, polar and geostationary satellite data, and numerical weather prediction output to develop a short term ‘nowcasting’ technique that blends analysis and forecast information
  • Improvements to numerical weather prediction models and their output, focusing on post-processing and model output statistics

Despite the broad scope of this effort, there are some efforts that have a lower likelihood of funding success and are not recommended for this call. Process-based research and case studies are not encouraged unless used as validation or in the context of algorithmic development for global application. Chemical speciation and other constituent analysis or modeling is also out of scope unless filling a gap in visibility assessment. Likewise, fundamental numerical model physics theory and development is discouraged unless sufficiently mature for testing and comparison within operational Navy forecast models.

Request for Planning Letters

The first step in the proposal process is for prospective investigators to prepare planning, allowing investigators to submit a short (three pages maximum) summary of their ideas on this topic for ONR to evaluate, provide technical feedback and indicate whether a full proposal would have a reasonable chance of success.

Refer to the current Marine Meteorology Planning Letter guidelines and indicate your desire to work with the OVERCAST project and team. Please note "OVERCAST Planning Letter ‘Your Last Name’" in your email subject line. If you do not receive acknowledged receipt within 10 days, please follow-up with a resend.

Important Dates

Planning letters and full proposals for the OVERCAST program will be accepted on a rolling basis.

However, note that ONR funding cycles operate on the federal fiscal year. Funding amounts and timing may vary year-to-year. Please use the following dates as guidelines for full consideration of funding into the next calendar year.

September 1: Last date to submit planning letters (please submit by e-mail to below).

October 1: Estimated response deadline by ONR to all submitted planning letters with proposal recommendation.

December 1: Earliest anticipated commencement of awards made with new fiscal year funding, depending on availability of funding and grant processing if the grant application was received by October 1.

All planning letters should be submitted by email to Josh Cossuth (

Interdisciplinary efforts with other areas of ONR Marine Meteorology interest may also copy planning letters to: Dan Eleuterio ( and Kate Mulreany (