Dynamics Explorer-1 (DE 1) High Altitude Plasma Instrument (HAPI) Data This directory gathers data for the HAPI instrument that flew on the DE 1 spacecraft. DE-1 was launched on 3 August 1981 into an elliptical orbit with an altitude range of 570 km to 23 000 km (3.63 Earth radii) and ceased operations in January 1991. /highres_vmsbin (NSSDC ID: 81-070A-05A) The HAPI data are stored in VAX-binary Stand-Alone Telemetry (SATM) files, which include the raw particle data, spacecraft orbital data and raw magnetic field data used in computing pitch angles. The data are generally in 0.5 second sweeps of 32 energy levels for 10 ion/electron detectors varying in pitch angle. Data are available from soon after launch (Aug 3, 1981) to instrument failure (Dec 1, 1981). The individual data files have names of the form yyyydddThhmm_de1_hapi_higres_satm_B.vmsbin (for a specific data file starting in hour hh and minute mm). There are extraction and conversion (counts, number flux, energy flux, distribution function) IDL codes (and possibly PV-WAVE). The following links provide access to data set documentation and software: (1) SFDU description of the instrument and associated files. ftp://nssdcftp.gsfc.nasa.gov/miscellaneous/documents/b46591.txt (2) SFDU description of the data file format. ftp://nssdcftp.gsfc.nasa.gov/miscellaneous/documents/b46592.txt (3) HOW_TO_USE_REDUCE_SATM.TXT Description of the IDL code ftp://nssdcftp.gsfc.nasa.gov/miscellaneous/documents/b46590.txt (4) A list of all data files (using HyydddhhmmB.SATM as names) with times covered ftp://nssdcftp.gsfc.nasa.gov/miscellaneous/documents/b46593.txt (5) Description of file (4) ftp://nssdcftp.gsfc.nasa.gov/miscellaneous/documents/b46589.txt NSSDC Contact: or phone 1-301-286-6695 for more information. Also , 1-301-286-0190 and , 1-301-286-6707 Please acknowledge the NASA National Space Science Data Center and the Principal Investigator for each instrument for data usage. Keywords: Sun-Earth Connections, space physics, magnetosphere, ionosphere Updated: 2002 Sep 11 by NASA Official: Dr. Joseph H. King, Head, NSSDC