Characterization and Removal of Solar Orbiter Heavy Ion Sensor Time of Flight Accidental - PowerPoint Presentation

1. Characterization and Removal of Solar Orbiter Heavy Ion Sensor Time of Flight Accidental TailsResearch by Evan Shimoun (Honors Capstone) with assistance of Faculty Advisor Professor Jim Raines, Professor Sue Lepri, and the SOHIS teamBackground and ProblemSolar Orbiter is a space probe orbiting the Sun over its polar regionsThe Heavy Ion Sensor collects various types of ion data from the sun's solar windNotably:Energy per Charge of the ionTime of Flight of the ion Ions occasionally pass through the sensor multiple at a time, resulting in an incorrect data recording of the time of flightThis is a Time of Flight Accidental, and the project's goal is to eliminate these from the dataThe accidentals tend to form a bar (a tail) to the right of the valid dataOne Day Energy per Charge vs Time of Flight Data with AccidentalsApproach and MethodsAll code written for this project was done in the IDL programming languagePlots were based on existing code written by Dr. Ryan DeweyEnergy per Charge is recorded as stepsTime of Flight (TOF) is recorded based on channelPlots are spectrograms of the Energy per Charge step vs the TOF channelThe greater the number of data points at a specific step and channel, the redder the point isThe lesser the number of data points at a specific step and channel, the bluer the point isFirst method calculated the percentiles for each step’s TOFData points with TOF greater than the step’s 85th percentile were eliminatedSecond method calculated the total number of data points in each stepThis was multiplied by a percent to obtain number of data points we wished to eliminateThis was then divided by 512, the number of TOF channels and then subtracted from each TOF channel at the stepOne Day Energy per Charge vs Time of Flight DataPercentile Method of Accidental Elimination (85th Percentile)One Day Energy per Charge vs Time of Flight DataStep Elimination Method(20% data points eliminated)One Day Energy per Charge vs Time of Flight DataStep Elimination Method(15% data points eliminated)One Day Energy per Charge vs Time of Flight DataStep Elimination Method(10% data points eliminated)ResultsThe current methods used were only partially effective in eliminating the Time of Flight AccidentalsMethod 1:The percentile method eliminated much of the tail, but failed to remove all of itMany valid data points were also inadvertently eliminatedFailed to eliminate accidentals near TOF of 0Method 2:The step elimination method was much more successful in properly maintaining valid dataProperly eliminated the accidentals near TOF of 0Failed to properly eliminate nearly all the TOF tailBoth methods also ran incredibly slow with the amount of data needing to be processedFuture StepsThe existing methods to attempt the removal of the Time of Flight Accidentals were failures, so a new method will be approachedWill be pursued during my continued research on this topic over the summerThe new method will be based upon the method used by Dr. Jason Gilbert to eliminate the TOF Accidentals from the Solar Wind Ion Composition SpectrometerThis method compares the recorded ion speed with the bulk speed of the solar wind to determine if the recorded ion speed makes logical senseAcknowledgementsProfessor Jim Raines for his support in my pursual of this projectProfessor Sue Lepri for providing me with the opportunity to join the SOHIS team and her continued support over the yearsDr. Ryan Dewey, Keeling Ploof, and Chris Bert for providing code to base my work off and aiding me when I ran into issues with said codeDr. Jason Gilbert for taking the time to meet with me and explain how he had previously dealt with TOF accidentalsThe rest of the SOHIS team for being supportive of my project