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Implementing a LORIPP-Compliant Option in the Loran-C User Position Software (LUPS). LORIPP Meeting July 24-25, 2002 Jaime Y. Cruz Illgen Simulation Technologies, Inc. jcruz@illgen.com / 805-692-2333 x 222. Background. LUPS v1 delivered by Illgen to the FAA in May 2001
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Implementing aLORIPP-Compliant Option in theLoran-C User Position Software (LUPS) LORIPP Meeting July 24-25, 2002 Jaime Y. Cruz Illgen Simulation Technologies, Inc. jcruz@illgen.com / 805-692-2333 x 222
Background • LUPS v1 delivered by Illgen to the FAA in May 2001 • LUPS v2 to be delivered September 27, 2002 • LUPS has been used to process flight test data • June 2001, New Jersey area, PC-104 and DDC receivers (ILA30) • August 2001, Cross-country, SatMate and DDC (Appendix A, Illgen Task 5 Progress Report, June 2002) • LUPS algorithm reference: Algorithm Description Document sections of IST2001-R-247, 25 May 2001 (to be updated for v2) Purpose of LORIPP-compliant option in LUPS: To provide software that can be used to exercise LORIPP developed integrity and error models using Loran-C flight test data.
LUPS Overview (1) • All-in-view: Uses a preliminary solution to align the TOE of the various chains • Propagation Delay Model: Millington-Pressey algorithm based on an edited version of the FCC M3 Ground Conductivity Database • Fault Detection and Exclusion: • t-test to exclude large residuals • FDE protection level is the maximum single-fault position shift caused by the maximum undetectable error in each measurement • chi-square test to assess goodness-of-fit of the error models against post-adjustment residuals.
LUPS Overview (2) • Weighted Least Squares: Weight matrix is the inverse of the a-priori covariance matrix of observation residuals. Includes terms for: • SNR-based TOA noise at the receiver • Secondary and Master transmitter timing errors • “Other” error sources • ASF spatial error covariance model • ASF/ED temporal variation covariance model • Reference variance for global scaling of all covariances The following charts discuss the effort needed to implement the LORIPP-compliant error and integrity models
Summary • Tasks involved in implementing a LORIPP-compliant option in LUPS: • Implement • ASF prediction error model • LORIPP ASF seasonal-variation error-model • LORIPP weight matrix • LORIPP RAIM (cycle-slip integrity monitor) • LORIPP HPL model • LORIPP diagnostic output as part of the LUPS output • Exercise LORIPP-compliant option using flight-test data • Deliver software • Deliver revised Algorithm Description Document • Deliver verification and validation test report.