Several numerical solutions of the three dimensional unsteady incompressible Navier-Stokes equations in generalized coordinate systems are presented. The governing equations are discretized by finite volumes with special care to the accurate approximation of the geometric quantities. The unknowns are the pressure and the volume fluxes over the computational cell faces. This formulation results in a robust fractional step solution method for solving discrete equations. Although this method is...

Topics: NASA Technical Reports Server (NTRS), DIGITAL SIMULATION, FINITE VOLUME METHOD, INCOMPRESSIBLE...

SpaceClaim/TD Direct has been used extensively in the development of the Advanced Stirling Radioisotope Generator (ASRG) thermal model. This paper outlines the workflow for that aspect of the task and includes proposed best practices and lessons learned. The ASRG thermal model was developed to predict component temperatures and power output and to provide insight into the prime contractors thermal modeling efforts. The insulation blocks, heat collectors, and cold side adapter flanges (CSAFs)...

Topics: NASA Technical Reports Server (NTRS), COMPUTER AIDED DESIGN, STIRLING CYCLE, COMPUTATIONAL GRIDS,...

Interpolation at grid boundaries is studied for the purpose of solving partial differential equations using either implicit or conservative explicit finite-difference methods on multi-component overlapping grid systems.

Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL FLUID DYNAMICS, COMPUTATIONAL GRIDS, NUMERICAL...

An all new, automated version of the PEGASUS software has been developed and tested. PEGASUS provides the hole-cutting and connectivity information between overlapping grids, and is used as the final part of the grid generation process for overset-grid computational fluid dynamics approaches. The new PEGASUS code (Version 5) has many new features: automated hole cutting; a projection scheme for fixing gaps in overset surfaces; more efficient interpolation search methods using an alternating...

Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL FLUID DYNAMICS, COMPUTATIONAL GRIDS, GRID...

This paper presents a methodology to determine the parameters used in the simulation of delamination in composite materials using decohesion finite elements. A closed-form expression is developed to define the stiffness of the cohesive layer. A novel procedure that allows the use of coarser meshes of decohesion elements in large-scale computations is proposed. The procedure ensures that the energy dissipated by the fracture process is correctly computed. It is shown that coarse-meshed models...

Topics: NASA Technical Reports Server (NTRS), FINITE ELEMENT METHOD, COMPOSITE MATERIALS, DELAMINATING,...

This paper presents a general three-dimensional algorithm for data transfer between dissimilar meshes. The algorithm is suitable for applications of fluid-structure interaction and other high-fidelity multidisciplinary analysis and optimization. Because the algorithm is independent of the mesh topology, we can treat structured and unstructured meshes in the same manner. The algorithm is fast and accurate for transfer of scalar or vector fields between dissimilar surface meshes. The algorithm is...

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, STRUCTURED GRIDS (MATHEMATICS), UNSTRUCTURED...

The design of ion optics for bombardment thrusters strongly influences overall performance and lifetime. The operation of a 30 cm thruster with accelerator grid open area fractions ranging from 43 to 24 percent, was evaluated and compared with experimental and theoretical results. Ion optics properties measured included the beam current extraction capability, the minimum accelerator grid voltage to prevent backstreaming, ion beamlet diameter as a function of radial position on the grid and...

Topics: NASA Technical Reports Server (NTRS), ACCELERATORS, BOMBARDMENT, GRIDS, ION ENGINES, MERCURY...

An effort to develop techniques to evaluate contour-to-grid interpolation algorithms. The use of synthetic surfaces as tool is explored. A set of synthetic surfaces is generated using Fourier Series to represent terrain with different degrees of ruggedness; each surface represented by an equation of the form: Z=F(X,Y). The results of a contour-to-grid interpolation can then be evaluated by comparison with the 'true elevations', the elevations calculated from the synthetic surfaces. (Author)

Topics: DTIC Archive, Loon, Joseph C, OHIO STATE UNIV RESEARCH FOUNDATION COLUMBUS, *ALGORITHMS,...

A traverse is a series of consecutive lines whose lengths and directions have been determined from field measurements. It is chiefly used to determine the mutual location of survey lines and station positions. Data reduction procedures have been applied to reduce slope distances to ellipsoidal distances to grid distances. Traverse computations were then performed in Universal Transverse Mercator grid coordinates. The computations included adjustment by the method of least squares observation...

Topics: DTIC Archive, Klangvichit, Supote, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *GRIDS(COORDINATES),...

Truncation-error analysis is a reliable tool in predicting convergence rates of discretization errors on regular smooth grids. However, it is often misleading in application to finite-volume discretization schemes on irregular (e.g., unstructured) grids. Convergence of truncation errors severely degrades on general irregular grids; a design-order convergence can be achieved only on grids with a certain degree of geometric regularity. Such degradation of truncation-error convergence does not...

Topics: NASA Technical Reports Server (NTRS), FINITE VOLUME METHOD, UNSTRUCTURED GRIDS (MATHEMATICS),...

A direct procedure is presented for locally bicubic interpolation on a structured, curvilinear, two-dimensional grid. The physical (Cartesian) space is transformed to a computational space in which the grid is uniform and rectangular by a generalized curvilinear coordinate transformation. Required partial derivative information is obtained by finite differences in the computational space. The partial derivatives in physical space are determined by repeated application of the chain rule for...

Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL GRIDS, COORDINATE TRANSFORMATIONS, FINITE...

Numerical analysis is attempted on the gasdynamics associated with flow over an anti-recoil plate. The blast field is analyzed under the assumptions that the presence of the precursor flow and projectile may be neglected. An existing shock-fitting code is used in order to determine its capability when computing impingement flowfields. While the code provided good prediction of the exhaust flow from the muzzle of the gun up until shock impingement, problems were encountered in treating the flow...

Topics: DTIC Archive, Moretti, Gino, G M A F INC FREEPORT NY, *GUN MUZZLES, *RECOIL MECHANISMS, COMBUSTION...

The purpose of the present study was to evaluate the capability of the computational fluid dynamics computer program PARC3D to model flow in a typical diffusing subsonic S-duct, with strong secondary flows. This evaluation is needed to provide confidence in the analysis of aircraft inlets, which have similar geometries. The performance predictions include total pressure profiles, static pressures, velocity profiles, boundary layer data, and skin friction data. Flow in the S-duct is subsonic,...

Topics: NASA Technical Reports Server (NTRS), COMPRESSIBLE FLOW, COMPUTATIONAL FLUID DYNAMICS,...

Important issues involved in working with complex geometries are discussed. Approaches taken to address complex geometry issues in the McDonnell Aircraft Computational Grid System and related geometry processing tools are discussed. The efficiency of acquiring a suitable geometry definition, the need to manipulate the geometry, and the time and skill level required to generate the grid while preserving geometric fidelity are discussed.

Topics: NASA Technical Reports Server (NTRS), AIRCRAFT CONFIGURATIONS, AIRCRAFT DESIGN, COMPUTATIONAL FLUID...

A method for locally fairing uniform cubic B-spline curves and surfaces is presented. The algorithm uses an automated technique which detects undesirable geometric characteristics by using a local fairness criterion. The geometric entity is then smoothed using a method based on the repeated removal and insertion of the spline knots in the vicinity of the geometric irregularity.

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, CURVES, GEOMETRY, GRID GENERATION (MATHEMATICS),...

The goal of this research was to further develop zonal methods and three dimensional procedures for application of finite difference methods to solve complex aircraft configurations. For the task of three dimensional grid generation both elliptic and hyperbolic methods were developed. A chimera grid scheme, that is, the use of overset multiple grid systems, was also tested in two dimensions. In zonal methods several new algorithms were developed. These included combining transonic potential...

Topics: DTIC Archive, Steger,J L, STANFORD UNIV CA DEPT OF AERONAUTICS AND ASTRONAUTICS,...

A NASA contractor and Small Business Innovation Research (SBIR) participant has converted its research into commercial software products for auto design, structural analysis and other applications. ViGYAN, Inc., utilizing the aeronautical research principle of computational fluid dynamics, has created - with VGRID3D and VPLOT3D - an easier alternative to conventional structured grids for fluid dynamic calculations.

Topics: NASA Technical Reports Server (NTRS), STRUCTURAL ANALYSIS, COMPUTATIONAL FLUID DYNAMICS, COMPUTER...

The overset grid methodology has significantly reduced time-to-solution of high-fidelity computational fluid dynamics (CFD) simulations about complex aerospace configurations. The solution process resolves the geometrical complexity of the problem domain by using separately generated but overlapping structured discretization grids that periodically exchange information through interpolation. However, high performance computations of such large-scale realistic applications must be handled...

Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL GRIDS, COMPUTATIONAL FLUID DYNAMICS,...

Nozzle boattail drag is significant for the High Speed Civil Transport (HSCT) and can be as high as 25 percent of the overall propulsion system thrust at transonic conditions. Thus, nozzle boattail drag has the potential to create a thrust drag pinch and can reduce HSCT aircraft aerodynamic efficiencies at transonic operating conditions. In order to accurately predict HSCT performance, it is imperative that nozzle boattail drag be accurately predicted. Previous methods to predict HSCT nozzle...

Topics: NASA Technical Reports Server (NTRS), BOATTAILS, CIVIL AVIATION, COMPUTATIONAL FLUID DYNAMICS,...

A very important, but often overlooked step in grid generation is acquiring a suitable geometry definition of the vehicle to be analyzed. In the past, geometry was usually obtained by generating a number of cross-sections of each component. A number of recent efforts have focussed on non-uniform rational B-spline surfaces (NURBS) to provide as single type of analytic surface to deal with inside the grid generator. This approach has required the development of tools to read other types of...

Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL GRIDS, COMPUTER AIDED DESIGN, GEOMETRY, GRID...

A technique is presented for adapting computational meshes used in the G2 version of the direct simulation Monte Carlo method. The physical ideas underlying the technique are discussed, and adaptation formulas are developed for use on solutions generated from an initial mesh. The effect of statistical scatter on adaptation is addressed, and results demonstrate the ability of this technique to achieve more accurate results without increasing necessary computational resources.

Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL GRIDS, MONTE CARLO METHOD, COMPUTERIZED...

The computer code GENIE++ is a continuously evolving grid system containing a multitude of proven geometry/grid techniques. The generation process in GENIE++ is based on an earlier version. The process uses several techniques either separately or in combination to quickly and economically generate sculptured geometry descriptions and grids for arbitrary geometries. The computational mesh is formed by using an appropriate algebraic method. Grid clustering is accomplished with either exponential...

Topics: NASA Technical Reports Server (NTRS), STRUCTURED GRIDS (MATHEMATICS), SMOOTHING, GRID GENERATION...

A versatile and efficient multi-block method is presented for the simulation of both steady and unsteady flow, as well as aerodynamic design optimization of complete aircraft configurations. The compressible Euler and Reynolds Averaged Navier-Stokes (RANS) equations are discretized using a high resolution scheme on body-fitted structured meshes. An efficient multigrid implicit scheme is implemented for time-accurate flow calculations. Optimum aerodynamic shape design is achieved at very low...

Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL FLUID DYNAMICS, PARALLEL PROCESSING...

A fast, recently developed, multiscale optimal interpolation algorithm has been adapted to the mapping of hydrographic and other oceanographic data. This algorithm produces solution and error estimates which are consistent with those obtained from exact least squares methods, but at a small fraction of the computational cost. Problems whose solution would be completely impractical using exact least squares, that is, problems with tens or hundreds of thousands of measurements and estimation grid...

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, INTERPOLATION, OCEANOGRAPHIC PARAMETERS, MAPPING,...

Stage separation process is an important phenomenon in multi-stage launch vehicle operation. The transient flowfield coupled with the multi-body systems is a challenging problem in design analysis. The thermodynamics environment with burning propellants during the upper-stage engine start in the separation processes adds to the complexity of the-entire system. Understanding the underlying flow physics and vehicle dynamics during stage separation is required in designing a multi-stage launch...

Topics: NASA Technical Reports Server (NTRS), STAGE SEPARATION, RELIABILITY ANALYSIS, COMPUTATIONAL FLUID...

Multigrid methods for the Navier-Stokes equations at low speeds and large temperature variations are investigated. The compressible equations with time-derivative preconditioning and preconditioned flux-difference splitting of the inviscid terms are used. Three implicit smoothers have been incorporated into a common multigrid procedure. Both full coarsening and semi-coarsening with directional fine-grid defect correction have been studied. The resulting methods have been tested on four 2D...

Topics: NASA Technical Reports Server (NTRS), MULTIGRID METHODS, COMPUTATIONAL GRIDS, NAVIER-STOKES...

The compressible Reynolds-averaged Navier-Stokes equations are solved for circulation control airfoil flows. Numerical solutions are computed with both structured and unstructured grid solvers. Several turbulence models are considered, including the Spalart-Allmaras model with and without curvature corrections, the shear stress transport model of Menter, and the k-enstrophy model. Circulation control flows with jet momentum coefficients of 0.03, 0.10, and 0.226 are considered. Comparisons are...

Topics: NASA Technical Reports Server (NTRS), CIRCULATION CONTROL AIRFOILS, NAVIER-STOKES EQUATION,...

The central focus was the study of algebraic multigrid (AMG), which was in fact developed under this project. Conventional or geometric multigrid algorithms depend on knowledge of the underlying geometry for a given problem (e.g., a partial differential equation). This knowledge is used to predetermine coarser grids and the attendant operators and intergrid transfer. Although very efficient solvers can be developed in this way, the dissemination and use of geometric multigrid have been impeded...

Topics: DTIC Archive, McCormick,Stephen F, RESEARCH INST OF COLORADO FORT COLLINS DEPT OF MATHEMATICS,...

NPS reviews several diagnostic and prognostic mesoscale windflow models which are currently being considered for use in evaluating plume releases ar Vandenberg Air Force Base. Some issues considered are the various model implementations of: (1) objective analysis; (2) mesoscale meteorological physics; (3) domain size, grid spacing and nesting; (4) lateral, top, and bottom boundary conditions; (5) solution methods; (6) validity of surface layer similarity in complex terrain; (7) temporal...

Topics: DTIC Archive, Kamada, Ray F, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *AIR FLOW, *WIND, TIME...

Poisson equation grid generators are the most popular differential equation mesh generation schemes. Results reported under this program show how to use the existing schemes to construct adaptive grids. Methods for controlling individual arc lengths as well as cell volumes are given and technique for constructing two-dimensional orthogonal adaptive grids are included. Adaptivity was also demonstrated with unstructured meshes using the Poisson equation as a control on grid point location....

Topics: DTIC Archive, Anderson, Dale A, TEXAS UNIV AT ARLINGTON COMPUTATION FLUIDS DYNAMICS CENTER,...

The linearly Tapered Slot Antenna (LTSA) has been the subject of considerable study and experimentation. Accurate theoretical models base on the Method of moments (MOM) have been developed to study the radiation characteristics of this antenna. however, these models are limited due to the great amount of Central Processing Unit (CPU) time required to obtain the solution. Employing the Numerical Electromagnetics Code (NEC) an accurate wire- grid model of the LTSA is developed here in order to...

Topics: DTIC Archive, Miller, Daniel K, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *RADIATION PATTERNS,...

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Topics: Smart power grids -- Security measures, Computer networks -- Security measures, Internet --...

The divide-and-conquer paradigm of iterative domain decomposition, or substructuring, has become a practical tool in computational fluid dynamics applications because of its flexibility in accommodating adaptive refinement through locally uniform (or quasi-uniform) grids, its ability to exploit multiple discretizations of the operator equations, and the modular pathway it provides towards parallelism. We illustrate these features on the classic model problem of flow over a backstep using...

Topics: DTIC Archive, Gropp, William D, INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING...

The quality of simulated hypersonic stagnation region heating on tetrahedral meshes is investigated by using a three-dimensional, upwind reconstruction algorithm for the inviscid flux vector. Two test problems are investigated: hypersonic flow over a three-dimensional cylinder with special attention to the uniformity of the solution in the spanwise direction and hypersonic flow over a three-dimensional sphere. The tetrahedral cells used in the simulation are derived from a structured grid where...

Topics: NASA Technical Reports Server (NTRS), HYPERSONIC FLOW, UNSTRUCTURED GRIDS (MATHEMATICS),...

The conical-domain model is a computational model, now undergoing development, for estimating ionospheric delays of Global Positioning System (GPS) signals. Relative to the standard ionospheric delay model described below, the conical-domain model offers improved accuracy. In the absence of selective availability, the ionosphere is the largest source of error for single-frequency users of GPS. Because ionospheric signal delays contribute to errors in GPS position and time measurements,...

Topics: NASA Technical Reports Server (NTRS), GLOBAL POSITIONING SYSTEM, ATMOSPHERIC MODELS, EARTH...

MarsLS is a software tool for analyzing statistical dispersion of spacecraft-landing sites and displaying the results of its analyses. Originally intended for the Mars Explorer Rover (MER) mission, MarsLS is also applicable to landing sites on Earth and non-MER sites on Mars. MarsLS is a collection of interdependent MATLAB scripts that utilize the MATLAB graphical-user-interface software environment to display landing-site data (see figure) on calibrated image-maps of the Martian or other...

Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL GRIDS, GRAPHICAL USER INTERFACE, SOFTWARE...

Message passing is among the most popular techniques for parallelizing scientific programs on distributed-memory architectures. The reasons for its success are wide availability (MPI), efficiency, and full tuning control provided to the programmer. A major drawback, however, is that incremental parallelization, as offered by compiler directives, is not generally possible, because all data structures have to be changed throughout the program simultaneously. Charon remedies this situation through...

Topics: NASA Technical Reports Server (NTRS), MESSAGES, ARCHITECTURE (COMPUTERS), DISTRIBUTED MEMORY, DATA...

Thermal Protection System (TPS) Cavity Heating is predicted using Computational Fluid Dynamics (CFD) on unstructured grids for both simplified cavities and actual cavity geometries. Validation was performed using comparisons to wind tunnel experimental results and CFD predictions using structured grids. Full-scale predictions were made for simplified and actual geometry configurations on the Space Shuttle Orbiter in a mission support timeframe.

Topics: NASA Technical Reports Server (NTRS), CAVITIES, COMPUTATIONAL FLUID DYNAMICS, HEATING, SIMULATION,...

In many time dependent simulations, the solution on most of the domain will be fairly smooth, with discontinuities or highly oscillatory phenomena occurring over only a small fraction of the domain. In problems such as these, a mesh refinement approach can be the most efficient, and often the only practical, solution method. Refined grids with smaller and smaller mesh spacing are placed only where they are needed. Since we are solving a time dependent problem, the regions needing refinement...

Topics: DTIC Archive, Berger, Marsha J, STANFORD UNIV CA DEPT OF COMPUTER SCIENCE, *FINITE DIFFERENCE...

A parallel C implementation of the marching cubes method is discussed. The input data for the code consists of a variation of the unformatted PLOT3D grid and solution files. PLOT3D files can define an irregularly or regularly spaced mesh and the associated scalars given by v(x,y, z), F(x,y,z), and S sub n = F(x,y,z), respectively. The output is a collection of three-sided polygons defining a constant value of F(x,y,z), and a second scalar which will be mapped onto this surface. The output is...

Topics: DTIC Archive, Burke, Kathy A, COMPUTER SCIENCES CORP FALLS CHURCH VA, *INPUT OUTPUT PROCESSING,...

This report describes the findings of JPL regarding geographic transformation algorithms used in MAGIIC, GUARDRAIL, TRAILBLAZER, AND BETA systems. A set of parameters is developed to characterize and catalogue intelligence system algorithms in the four systems. Individual algorithms are also analyzed to determine if they are performing their functions properly.

Topics: DTIC Archive, Babby,P, JET PROPULSION LAB PASADENA CA, *ALGORITHMS, *MILITARY INTELLIGENCE,...

Investigation of steady and unsteady flowfields over airfoils is an active area of current computational and experimental research. In this study, the compressible, viscous, flow over a single and multi-element airfoil is numerically simulated by solving the Navier Stokes equations. The motivation for this work includes interest in studying the effects of a stationary/flapping airfoil combination in tandem configuration. A single-block Navier-Stokes (NS) solver is employed to compute unsteady...

Topics: DTIC Archive, Ortiz, Miguel A., NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *COMPUTATIONAL FLUID...

The flow in the transonic test facility was investigated using the three dimensional computational fluid dynamics techniques. The application of the full Navier-Stokes three dimensional code to the flow qualities in the contraction section of transonic wind tunnel is discussed. Initially, two dimensional solutions indicated the possibility for large secondary flow to exist as a result of the asymmetries involved in the contraction section as it is constructed. The results of a full three...

Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYER FLOW, COMPUTATIONAL FLUID DYNAMICS,...

Given the mission objective to deploy a number of small landers to the surface of Mars at various latitude/longitude locations, it is of interest to obtain a global perspective of the communications link geometry between the landers and a data relay orbiter. Specifically, the question to be answered is what is the total time interval over one Martian day (1 sol) that a lander at any given latitude and longitude can communicate data to the orbiter. Results should be obtained for more than one...

Topics: NASA Technical Reports Server (NTRS), ANTENNA DESIGN, COMMUNICATION NETWORKS, DATA LINKS, ELEVATION...

From 2015-2017, the DoD conducted a Plug-in Electric Vehicle - Vehicle to Grid (PEV-V2G) demonstration at four locations of non-tactical motor fleets - Los Angeles Air Force Base, Fort Hood, Joint Base Andrews and Joint Base McGuire-Dix-Lakehurst. V2G technologies provide financial and operational incentives to use PEVs beyond their primary function as vehicles. The concept of V2G is that a PEV is connected to the electrical grid via a bi-directional charging station. This allows the PEV...

Topics: DTIC Archive, Brendlinger,Jennifer, E2 Technologies LLC Dayton United States, PLUGIN ELECTRIC...

Transducer measures pressure by sensing the damping of a vibrating diaphragm immersed in the atmosphere to be measured. Improved sensor can be included in rugged, lightweight package for use aboard aircraft, meteorological vehicles, and space probes.

Topics: NASA Technical Reports Server (NTRS), AMPLITUDES, DAMPING, DIAPHRAGMS, GRIDS, HIGH PRESSURE, IRON,...

As a preliminary step toward predicting the leeside thermal environment for winged reentry vehicles at flight conditions, a computational solution for the flow about the Shuttle Orbiter at wind tunnel conditions was made using a point-implicit, finite volume scheme known as the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA). The surface pressures resulting from the computational solution are compared with wind tunnel data. The results indicate that the dominant inviscid flow...

Topics: NASA Technical Reports Server (NTRS), AEROTHERMODYNAMICS, ANGLE OF ATTACK, COMPUTATIONAL FLUID...

While digital terrain grids are now in wide use, accurate delineation of drainage basins from these data is difficult to efficiently automate. A recursive order N solution to this problem is presented. The algorithm is fast because no point in the basin is checked more than once, and no points outside the basin are considered. Two applications for terrain analysis and one for remote sensing are given to illustrate the method, on a basin with high relief in the Sierra Nevada. This technique for...

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, DIGITAL TECHNIQUES, DRAINAGE, HYDROLOGY,...

A method for solving the viscous hypersonic flow field around realistic configurations is presented. The numerical procedure for generating the required finite difference grid and the two-factored implicit flow solver are described. Results are presented for the shuttle orbiter and a generic wing-body configuration at hypersonic Mach numbers.

Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CONFIGURATIONS, BODY-WING CONFIGURATIONS,...

The use of objectively analyzed fields of meteorological data for the initialization of numerical prediction models and for complex diagnostic studies places the requirements upon the objective method that derivatives of the gridded fields be accurate and free from interpolation error. A modification was proposed for an objective analysis developed by Barnes that provides improvements in analysis of both the field and its derivatives. Theoretical comparisons, comparisons between analyses of...

Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL GRIDS, MATHEMATICAL MODELS, METEOROLOGICAL...