New Horizons Pluto Energetic Particle Spectrometer Science Investigation

New Horizons Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) PRINCIPAL INVESTIGATOR: Ralph Mc. Nutt, APL DESCRIPTION: Medium Energy Particle Spectrometer ENERGY RANGE: 25 -1000 ke. V (protons) 60 -1000 ke. V (atomic ions) 25 -500 ke. V (electrons) FIELD OF VIEW: 160 deg x 12 deg ANGULAR RESOLUTION: 25 deg x 12 deg ENERGY RESOLUTION: 0. 25 ke. V SENSOR SIZE: 7. 6 cm dia. x 2. 5 cm thick POWER: 1. 4 watt MASS: 1. 5 kg

New Horizons PEPSSI Data Sets RAW -> nh-x-pepssi-2 -pluto-v 1. 0 CALIBRATED -> nh-x-pepssi-3 -pluto-v 1. 0

New Horizons PEPSSI Data Set Evaluation Tools All Data Processing and Evaluation Machine: Dell Precision M 4800 Operating System: Windows 10

Documentation Evaluation

nh-x-pepssi-2 -pluto-v 1. 0/catalog nh-x-pepssi-3 -pluto-v 1. 0/catalog Root Level Files Neither the AADREADME. TXT nor the VOLDESC. CAT tell the user much that is useful regarding the contents of these archive volumes (i. e. date/time of Pluto closest Approach, name of the directory containing those data, etc. ). While you can dig through lots of documents and catalog files and eventually find that information, it’s quicker and easier to just go to Wikipedia. Unfortunately Wikipedia can’t tell you that the data from July 14 are located in a directory named: 20150713_029913

nh-x-pepssi-2 -pluto-v 1. 0/catalog nh-x-pepssi-3 -pluto-v 1. 0/catalog dataset. cat Additional detail should be added to both dataset. cat files describing the operation of PEPSSI during the pluto mission phase. Data included is this delivery are for the most part very low resolution solar wind data. There’s a little bit of high res Pluto data in one file. While this dataset will eventually contain more Pluto data, the ds. cat file should reflect the data as they are now, and be updated later when additional data are available to the public. Documentation does not make it clear if high resolution data are available from time periods where only low res data are provided in this release or if this is all that can be expected except for gap fill.

nh-x-pepssi-2 -pluto-v 1. 0/catalog nh-x-pepssi-3 -pluto-v 1. 0/catalog nhsc. cat ► Previously reported by Rudy and still present: Unable to locate Figure 5: The 16 rocket engine assemblies (REAs) are organized into 8 sets and placed on the spacecraft as shown in Figure 5 of [FOUNTAINETAL 2008]. Unable to locate Table II: Control rates for each of the spacecraft axes are shown below in Table II. shown in [FOUNTAINETAL 2008] Table 2.

nh-x-pepssi-2 -pluto-v 1. 0/catalog nh-x-pepssi-3 -pluto-v 1. 0/catalog ref. cat ► Rudy previously reported being unable to locate the following references: Consider adding a statement in the REX comment area of REF. CAT indicating that these documents are ITAR controlled and may not be easily obtained. Maybe give instructions as to how the documents can be obtained by U. S. persons as defined under ITAR.

nh-x-pepssi-2 -pluto-v 1. 0/document nh-x-pepssi-3 -pluto-v 1. 0/document soc_inst_icd. pdf - 1 As previously reported by Rudy, RATEBOXDEFINITIONPLANES. FIT not found as stated in the ICD page 76 c. For ease of use, we have added a column giving the deduced “Rate Box” of High-Ion PHA and Electron PHA events to the Level 2 PHA data. While this can, in principle, be calculated from the raw Level 2 quantities and the RATEBOXDEFINITIONPLANES. FIT file available in the CALIB/ directory of the PDS archive, the procedure is complex enough that we have found it convenient to perform this calculation in advance and include the information in the Level 2 files. the DOCUMENT/ directory Either update the ICD to reflect that the file is located in the DOCUMENT/ directory or move the file to the CALIB/ directory to be consistent with the ICD.

Data Evaluation

FV view of level-3 Flux table for day of Pluto C/A pep_0299137915_0 x 691_sci. fit Row 1 looks valid. After that, the data are nonsense. It is unclear if this is an FV problem or if the FITS header is incorrectly defined. This occurs in all flux tables that I checked with FV. The other tables in the files appear to be correct.

Electrons at Pluto Annotated plot of the electrons on the day of the Pluto flyby (24 hrs shown, day 195). C/A Plot from R. Frahm Counts below ~104 cutoff seen in low res solar wind 2 hrs Low resolution data High Res

Low Energy Ion TOF Directional Data Mostly low resolution data with a burst of high res 90 minutes or so after C/A. Top panel shows ions whose direction is unknown and the panels below show directions 0 -5 increasing downward. C/A Unknown Plot from R. Frahm 0 1 2 3 4 5 high res

Low Energy Ion TOF Directional Data (2) Blow-up of ~40 min high resolution segment of the low energy ion time-of flight (TOF) data. There is a strong difference in the low res data on either side of the high res interval which is odd given that the high res data look rather uniform over this interval. There also appear to be missing fast ions in the low res data that are particularly apparent in dirs 0, 1 and 5. Plot from R. Frahm direction 0 direction 1 direction 5

nh-x-pepssi-2 -pluto-v 1. 0/catalog nh-x-pepssi-3 -pluto-v 1. 0/catalog dataset. cat (2) The is an apparent disconnect between the low resolution data shown in the previous few plots relative to the adjacent high resolution data. I do not see any mention of how or why this would occur in either the ICD or the dataset. cat files of these two datasets. The dataset. cat files are single dataset documents that should be easier to modify than the ICD. I suggest adding a paragraph to the catalog files explaining how/why this disconnect occurs. I’m assuming that it is occurring in some onboard binning or averaging process and may be as simple as having a limited number of bins, with none centered in the regions where the counts are seen in the high res data. Whatever the source, the issue should be described in the documentation.

Summary of Liens 1. Correct issues with nhsc. cat as described on slide 7 of this presentation 2. Update ref. cat to include comment similar to that given on slide 8 in the REX comment area. 3. Issue with the location of the RATEBOXDEFINITIONPLANES. FIT file. Either update the ICD to reflect that the files is located in the /document directory or move the file to the /calib directory as stated in the ICD. 4. Update the dataset. cat files for both datasets a) Include information specific to this data release as discussed on slide 6. This information can be updated during the next release to reflect the content of both releases. As it currently stands, there is very little documentation that is specific to these volumes as they are being released to the public. b) Discuss the disconnect between the low res and high res portions of the data files as shown on slides 12 -14 and discussed on slide 15. In my opinion, the data can be certified with minor liens and released immediately, as long as Rudy concurs.