Michael S. Bielas

Stochastic and dynamic modeling of fiber gyros

Motivation is given for the development of dynamic and stochastic models of fiber optic gyros. Presented is a nonlinear system model of the fiber gyros closed-loop optics and electronics that is simplified to a linear discrete dynamic model. Given are some of the issues arising in applying the discrete transfer function of the fiber gyro under deterministic forcing functions. The model is extended to include the gyros output response to stochastic inputs. The resulting stochastic model includes the effects of the data acquisition system and quantization in the overall response. Discussed are techniques for evaluating the performance, both deterministic and random. Novel application of the Fourier filtering technique to simulate various types of random gyro noise, especially the mathematically pathological 1/f noise, is presented. A brief gallery of commonly applicable gyro noise is given.

Fiber-optic gyro development for a broad range of applications

Progress in fiber-optic gyroscope development at Honeywell is reported here. The results illustrate the versatility of the technology, showing its potential to meet both the low-cost, small-sized needs of tactical guidance, as well as the very high perfomance needs of inertial navigation and precision applications. In the case of inertial navigation, data is presented that illustrates the possibility of employing a low-cost depolarized design for this use.

Progress in interferometric fiber optic gyroscopes for space inertial reference units

The paper discusses the range of applications for interferometric fiber optic gyroscopes IFOGs in space inertial reference units (IRUs) with an emphasis on satellite usage. The requirements for space IRUs are discussed along with the corresponding features that give IFOGs a singular advantage for many space IRU applications. Development of Honeywells high performance closed-loop IFOG IRU product is described. Radiation tolerance is a key challenge in many space applications. Accordingly, another possibility for achieving high radiation tolerance using a depolarized IFOG (D-IFOG) is given. Test results for the high performance IFOG for space IRUs is presented as well as open-loop D-IFOG test results.

Test Results Of A Prototype Serrodyne Closed-Loop Interferometric Fiber Optic Gyroscope

The test results of a prototype serrodyne closed-loop interferometric fiber optic gyroscope are reported. The rotation sensor used a low-coherence superradiant diode at 0.85 microns wavelength with a polarization-maintaining sensing coil, polarizer and loop coupler. A wide bandwidth Ti:LiNb03 phase modulator was used to provide bias modulation and serrodyne frequency shifting. Performance of the sensor before and after loop closure is discussed. No degradation of the random walk or bias stability was noted with loop closure. The scale factor and dynamic range were improved. Various contributors to scale factor error are discussed.