Orekit issueshttps://gitlab.orekit.org/orekit/orekit/-/issues2021-01-12T13:38:37Zhttps://gitlab.orekit.org/orekit/orekit/-/issues/745Add Sequential-Batch Least Squares2021-01-12T13:38:37ZBryan CazabonneAdd Sequential-Batch Least SquaresBatch Least Squares main problem can be describe as follow:
"_Suppose we have 1000 observations and we perform an iterative loop to find the best answer to the state space of the system. But just as we finish converging on the answer, we receive 30 new observations. We could redo the process, using 1030 observations, but that is a waste of time because we've already extracted the information from the first 1000._"
Sequential-Batch Least Squares allows using the statistical information from the least squares processing of the first 1000 observations, and combine it with the new information.
More details are given in: Vallado D., Fundamentals of astrodynamics, Chapter 10.5.Batch Least Squares main problem can be describe as follow:
"_Suppose we have 1000 observations and we perform an iterative loop to find the best answer to the state space of the system. But just as we finish converging on the answer, we receive 30 new observations. We could redo the process, using 1030 observations, but that is a waste of time because we've already extracted the information from the first 1000._"
Sequential-Batch Least Squares allows using the statistical information from the least squares processing of the first 1000 observations, and combine it with the new information.
More details are given in: Vallado D., Fundamentals of astrodynamics, Chapter 10.5.11.1https://gitlab.orekit.org/orekit/orekit/-/issues/653Add Brouwer-Lyddane Method2021-01-12T10:10:14ZRyan ClubbAdd Brouwer-Lyddane MethodIt would be useful to have a Propagator class that uses the Brouwer-Lyddane method. This would be particularly useful to be able to convert osculating orbital elements into the Brouwer-Lyddane mean orbital elements, which as of now is not part of Orekit to my knowledge.
Original discussion on the forum: https://forum.orekit.org/t/brouwer-lydanne-conversion-between-mean-and-osculating-elements/706It would be useful to have a Propagator class that uses the Brouwer-Lyddane method. This would be particularly useful to be able to convert osculating orbital elements into the Brouwer-Lyddane mean orbital elements, which as of now is not part of Orekit to my knowledge.
Original discussion on the forum: https://forum.orekit.org/t/brouwer-lydanne-conversion-between-mean-and-osculating-elements/70611.1https://gitlab.orekit.org/orekit/orekit/-/issues/523Add support for loading RINEX navigation file2021-03-02T10:46:59ZGowtham SivaramanAdd support for loading RINEX navigation fileOrekit (as of v9.3) supports RINEX (measurement/observation files) versions 2.x and 3.x. But the support for loading navigation files (Eg: ftp://cddis.nasa.gov/gnss/data/daily/2019/035/19n/brdc0350.19n.Z) is lacking. The RINEX data format document (ftp://igs.org/pub/data/format/rinex301.pdf
) discusses the format of navigation file broadcasted.
Similar to SEM/YUMA parsers, the support to run GPSPropagator at the end of loading RINEX navigation files can be made available.Orekit (as of v9.3) supports RINEX (measurement/observation files) versions 2.x and 3.x. But the support for loading navigation files (Eg: ftp://cddis.nasa.gov/gnss/data/daily/2019/035/19n/brdc0350.19n.Z) is lacking. The RINEX data format document (ftp://igs.org/pub/data/format/rinex301.pdf
) discusses the format of navigation file broadcasted.
Similar to SEM/YUMA parsers, the support to run GPSPropagator at the end of loading RINEX navigation files can be made available.11.0