Remote sensing applications in forestry. The development of spectro-signature indicators of root disease impacts on forest stands Annual progress report
Spectral signature indicators of root disease impacts on forest stands
Wear, J. F.↗
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Extension of square-root filtering to include process noise.
Square root filters algorithms based on covariance and invariance matrices extended to include process noise effects
Dyer, P.↗
Synthesis of systems with dominant complex roots
Multiparameter systems with dominant complex roots constrained by degrees of freedom to construct reduced characteristic equation
Cadena, J. E.↗
A generalized root locus following technique
Feedback control system characteristic equation generalized root locus following technique using straight line approximation
Mcdaniel, W. L., Jr.↗
Automatic error bounds for real roots of polynomials having interval coefficients
Polynomials with interval coefficients, presenting Newton Raphson algorithm for real roots error bounds
Hanson, R. J.↗
An examination of simple coordinate transformations in the Z-plane and W-plane for root locus analysis of sampled-data systems
Examination of simple coordinate transformations in Z-plane and W-plane for root locus analysis of sampled data systems
Kozoil, J. S., Jr.↗
An approximate root locus method in the S plane for sampled-data systems
Approximate root locus method in S plane for sampled data systems, mapping constant frequency and constant damping ratio loci onto W plane
Koziol, J. S., Jr.↗
The development of spectro-signature indicators of root disease
The development and testing of airborne sensors that might be effective in discrimination root rot infected trees from healthy ones are outlined. The sensing device is composed of a thermal infrared radiometer and an instant replay video scan system.
Wear, J. F.↗
A square root formulation for the combined state-parameter estimator with application to the identification of sailplane performance
A square root formulation is presented for the discrete combined state parameter estimation problem with linear plant dynamics, Gaussian random disturbances, and constant but uncertain parameters. The estimator is a combination of the classical Kalman filter and a maximum likelihood algorithm which maximizes the parameter log-likelihood function using a first order search routine.
Froidevaux, M. R.↗
Derivation of formulas for root-mean-square errors in location, orientation, and shape in triangulation solution of an elongated object in space
Formulas are derived for the root-mean-square (rms) displacement, slope, and curvature errors in an azimuth-elevation image trace of an elongated object in space, as functions of the number and spacing of the input data points and the rms elevation error in the individual input data points from a single observation station. Also, formulas are derived for the total rms displacement, slope, and curvature error vectors in the triangulation solution of an elongated object in space due to the rms displacement, slope, and curvature errors, respectively, in the azimuth-elevation image traces from different observation stations. The total rms displacement, slope, and curvature error vectors provide useful measure numbers for determining the relative merits of two or more different triangulation procedures applicable to elongated objects in space.
Long, S. A. T.↗
A square-root data array solution of the continuous-discrete filtering problem
The Dyer-McReynolds (1969) discrete square-root filtering algorithm is extended to accommodate continuous dynamics. Differential equations are given to represent the time evolution of the filter data array. These equations are nonlinear, but it is shown that the nonlinearities act to enhance the stability of the solution.
Bierman, G. J.↗
Square-root algorithm for evaluating mismodeled process noise
As the application of sequential filters has grown, the need has arisen to evaluate the sensitivity of these filters to mismodeling of the random process. A numerically reliable square-root algorithm is developed for calculating the covariances of estimates from a sequential filter which incorrectly models process noise. Mismodeling is restricted to the correlation time and standard deviation of a random process represented as a first-order Gauss-Markov sequence. Using a computer program which employs this algorithm, a sensitivity analysis was performed for several types of earth-based tracking data from an interplanetary spacecraft.
Thornton, C. L.↗
The treatment of bias in the square-root information filter/smoother
The Dyer-McReynolds square-root information filter (SRIF) is rederived, using recursive least-square arguments. The result is applied to a system composed partly of biases. The filter sensitivity matrix, computed covariance, and consider covariance for this augmented system are reviewed. A new computationally attractive representation for the smoothed estimates, in terms of a smoothed sensitivity matrix and a smoothed computed covariance is presented.
Bierman, G. J.↗
Platform for a swing root turbomachinery blade
A rotor apparatus, comprising a blade having a root adapted to swing laterally within a supporting spindle under impact loading, is provided with a flow path defining platform. The platform comprises an inner shroud extending generally laterally of the blade airfoil portion and adapted to swing laterally. In one embodiment, wherein the blade primarily comprises a laminate of composite filament plies, the inner shroud is bonded to the laminate. An outer shroud, fixed with respect to the supporting spindle, forms a lateral extension of the inner shroud with the blade in its normal operating position. The inner and outer shrouds are provided with a pair of complementary adjacent surfaces contoured to pass in relatively close-fitting relationships to each other when the blade swings under impact loadings.
Ravenhall, R.↗
A pseudo root-locus method for the design of a class of two-input-two-output systems
This paper presents the design of digital rebalance loops for a tuned-rotor gyro which is intended to be an attitude sensor in a strapdown inertial measurement unit. A tuned-rotor gyro is a two-degree-of-freedom gyro which has two input axes, with cross-coupling between them. The rebalance loop of the gyro serves for two purposes. First, it restores the position of the rotor to its null position after experiencing an attitude input. Second, the rebalancing signal, which is proportional to the attitude change, is calibrated to give the desired attitude information. Since the gyro has more than one input and one output, a multivariable control technique is needed for designing the rebalance loop. The analytic model for the gyro is described and the available design methods are examined. A new root-locus design technique specially developed for the present problem is outlined. The design of the rebalance loop using the new technique is given. The computer simulation result of the designed system is presented and discussed.
Kao, M. K.↗
On Nth roots of positive operators
A bounded operator A on a Hilbert space H was positive. These operators were symmetric, and as such constitute a natural generalization of nonnegative real diagonal matrices. The following result is thus both well known and not surprising: A positive operator has a unique positive square root (under operator composition).
Brown, D. R.↗
An application of the square-root information filter to large scale linear interconnected systems
The paper considers the use of numerically stable square-root information filter (SRIF) algorithms to reduce the computation and storage requirements of a certain class of large-scale linear interconnected systems (multistation satellite tracking is examined as an example). The reductions are in comparison with conventional sequential covariance type formulations. To illustrate the SRIF algorithm: a 40 subsystem, 10 state problem, for example, has its storage requirements reduced by a full order of magnitude (from 84255 to 8100).
Bierman, G. J.↗