Spartan Band: Burnett\u27s 13th Texas Cavalry in the Civil War

New drama in the western theatre Unit fought in Vicksburg, Red River, and Camden campaigns Thomas Reid\u27s Spartan Band: Burnett\u27s 13th Texas Cavalry in the Civil War is a splendidly crafted account of an East Texas cavalry regiment formed in 1862. Like many Texas cavalry un...

From Sea To Cd: Full-Text Search Capability Makes Orns Faster, Easier To Use

One of the best researchers this reviewer has known once told him that even the smell of paper and binding glue in old volumes adds to the atmosphere of historical research. As a traditional historian, I agree. However, things change. As technological advances occur at a dizzying pace, new produc...

Iron From the Deep: The Discovery and Recovery of the USS Monitor

Poseidon\u27s treasure Reclaiming American naval history The story of the most famous Union vessel of the Civil War is the subject of Robert E. Sheridan\u27s Iron From the Deep: The Discovery and Recovery of the USS Monitor. The volume is one in a long line of fine naval litera...

Innovative Sailing: A Definitive Biography Of The Confederacy\u27s Naval Tactician

Biographies of Civil War era naval officers are a scarce commodity and those of Southern officers are most rare. Craig L. Symonds has created a superb piece of writing in Confederate Admiral, his new volume on the life of Franklin Buchanan. The result is an impressive telling of the life of t...

Champion Hill: Decisive Battle for Vicksburg

Battle\u27s first broad study Confederate loss sealed fate of the campaign and the war in the west Individual battles in large Civil War campaigns often receive less attention in research and publication space than they deserve. This is perhaps more true in the Western Theatre than ...

Walker\u27s Texas Division, C.S.A.: Greyhounds of the Trans-Mississippi

Commendable contribution Texans bolstered Confederate cause Dr. Richard Lowe, Regents Professor of History at the University of North Texas, has crafted a superb and much-needed history of one of the great military units of the Confederacy in his Walker\u27s Texas Division: Greyh...

Pitfalls of Interchange Designs: Observations Relating to IDM Chapter 48

This session covers common challenges found on freeway interchange designs here in Indiana. We will go over in detail common pitfalls observed from performing multiple design reviews and problems with designs that do not conform to the still-new Indiana Design Manual (IDM) Chapter 48, “Interchanges.” We will also offer conventional design solutions and alternatives to address these issues and challenges

Efficient Methods to Assimilate Satellite Retrievals Based on Information Content

One of the outstanding problems in data assimilation has been and continues to be how best to utilize satellite data while balancing the tradeoff between accuracy and computational cost. A number of weather prediction centers have recently achieved remarkable success in improving their forecast skill by changing the method by which satellite data are assimilated into the forecast model from the traditional approach of assimilating retrievals to the direct assimilation of radiances in a variational framework. The operational implementation of such a substantial change in methodology involves a great number of technical details, e.g., pertaining to quality control procedures, systematic error correction techniques, and tuning of the statistical parameters in the analysis algorithm. Although there are clear theoretical advantages to the direct radiance assimilation approach, it is not obvious at all to what extent the improvements that have been obtained so far can be attributed to the change in methodology, or to various technical aspects of the implementation. The issue is of interest because retrieval assimilation retains many practical and logistical advantages which may become even more significant in the near future when increasingly high-volume data sources become available. The central question we address here is: how much improvement can we expect from assimilating radiances rather than retrievals, all other things being equal? We compare the two approaches in a simplified one-dimensional theoretical framework, in which problems related to quality control and systematic error correction are conveniently absent. By assuming a perfect radiative transfer model and perfect knowledge of radiance and background error covariances, we are able to formulate a nonlinear local error analysis for each assimilation method. Direct radiance assimilation is optimal in this idealized context, while the traditional method of assimilating retrievals is suboptimal because it ignores the cross-covariances between background errors and retrieval errors. We show that interactive retrieval assimilation (where the same background used for assimilation is also used in the retrieval step) is equivalent to direct assimilation of radiances with suboptimal analysis weights. We illustrate and extend these theoretical arguments with several one-dimensional assimilation experiments, where we estimate vertical atmospheric profiles using simulated data from both the High-resolution InfraRed Sounder 2 (HIRS2) and the future Atmospheric InfraRed Sounder (AIRS)