ASPOC Datasets

The Active Spacecraft Potential Control (ASPOC) generates beams of indium ions to limit positive spacecraft potentials within +4V in order to improve the measurements obtained by FPI, HPCA, ADP, and SDP (Torkar et al., 2014). There are two ASPOC per MMS spacecraft.

For questions about the technical details of ASPOC or its data products, contact the ASPOC Lead Co-I, Phase E: Dr. R. Nakamura, IWF

ASPOC Level-2 Version Release Notes

Version	Mode	Release Date	Notes
1.0.*	SRVY	September 1, 2015	Initial Public Release
2.0.*	SRVY	February 25, 2016	Fixed file naming issues for files generated on December 31st Fixed CDF non-conformances with respect to flares ticket MMSSDC-107 Fixed FILLVALUE issues (-1.0E30 --> -1.0E31) Fixed data averaging for L2 CDF data files Improved PODA data retrieval and processing tool Enhanced log file entries and removed hard-coded LUN for manifest file Setting CDF_TMP environment variable to prevent parallel processing issues

Click on the dataset name for information about the file contents.

Level-2 Ion Beam Current and Energy
Sensor	Data Mode	Variable Name	Units	Comments
ASPOC	Fast/Slow Survey	Epoch	ns	Survey data acquisition time; derived from packet time.
ASPOC	Fast/Slow Survey	mms_aspoc_ionc	uA	Ion Emission Current Sum
ASPOC	Fast/Slow Survey	mms_asp1_ionc	uA	Unit 1 Ion Emission Current
ASPOC	Fast/Slow Survey	mms_asp2_ionc	uA	Unit 2 Ion Emission Current
ASPOC	Fast/Slow Survey	mms_asp1_energy	kV	Unit 1 Emitted Beam Energy
ASPOC	Fast/Slow Survey	mms_asp2_energy	kV	Unit 2 Emitted Beam Energy
ASPOC	Fast/Slow Survey	mms_aspoc_status	n/a	Instrument status bytes: [1] = Data quality [2] = Unit 1 mode [3] = Unit 2 mode [4] = On/Off status
ASPOC	Fast/Slow Survey	mms_aspoc_lbl	n/a	Instrument Status Labels
ASPOC	Fast/Slow Survey	mms_aspoc_var	ns	Half Width of Measurement Interval

The ASPOC Data Products Guide contains detailed information regarding both the instrument and the Level-2 data products available through this site. Detailed descriptions of the variables and attributes within the cdf files are included to enable users to extract the information they need.

The Data Product Guide is available in PDF format here:
ASPOC_Data_Products_Guide