AZUR/EI-88: Medium-energy low-altitude trapped proton and alpha-particle data (1969–1970)
type: Dataset
description: ## AZUR The magnetically aligned spacecraft AZUR (also called GRS-A), launched into a near-polar orbit on 08 Nov 1969, was a product of a joint effort by NASA-GSFC and the German _Bundesministerium fuer Wissenschaftliche Forschung_ (BMWF) and had as its primary purpose the acquisition of terrestrial radiation belt data. The instrument complement included detectors to measure the directional and omnidirectional fluxes of protons and electrons. These instruments and the high quality of the resulting measurements made the AZUR mission particularly well suited for the study of the trapped radiation environment, despite the short duration of the mission. ## Experiment EI-88 The energetic proton measurements, which were collected during the maximum of Solar Cycle 20, were the basis for the low altitude part of the NASA model AP-8 MAX [Sawyer & Vette, 1976]. The payload consisted of seven instruments. Descriptions of each instrument package can be found in [Achtermann et al., 1970] (see also [Hovestadt et al., 1972]). The EI-88 experiment consisted of two identical proton-alpha particle telescopes, one oriented perpendicular and one oriented at 45 degrees with respect to the local magnetic field vector. In the northern hemisphere, the 45 degree telescope pointed upwards. The telescopes detected protons and alpha particles in the Earth's trapping region. Unfortunately, the data gathered after 5 March 1970 have been lost. __Principal Investigator__: D.K. Hovestadt, Max Planck Institut fuer Extra-Terrestrische Physik ## Dataset In the framework of the ESA/ESTEC [TREND-2] study, D. Heynderickx restored the data from the original NSSDC magnetic tapes [69-097A-02A,04A], performed detailed data checks and removed bad and suspicious data records. In the framework of the ESA/ESTEC [TREND-3] study, magnetic parameters were computed using [UNILIB]. ## Acknowledgment * National Space Science Data Center, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. * D.K. Hovestadt, Max…
landing page: https://data.aeronomie.be/dataset/c6e07f22-b7b9-421c-858c-d3c991ffe6f7
version info: 1
accrual periodicity: AS_NEEDED
keyword: AP-8 MAX
keyword: AZUR
keyword: Radiation Belts
issued: 2026-08-25T08:12:14.712824
modified: 2026-08-27T08:29:07.000305
conforms to: 10.48322/E72C-5Y75
contact point: Organization
  fn: Royal Belgian Institute for Space Aeronomy
  fn: Institut royal d'Aéronomie Spatiale de Belgique @fr
  fn: Koninklijk Belgisch Instituut voor Ruimte-Aeronomie @nl
publisher: Royal Belgian Institute for Space Aeronomy
temporal: PeriodOfTime
  start date: 1969-11-16
  end date: 1970-03-15
spatial: Location
temporal resolution: PT10S
language: ENG
theme: TECH
identifier: 40t59lob
bibliographic citation: Heynderickx, D., & Kruglanski, M. (2026). AZUR/EI-88: Medium-energy low-altitude trapped proton and alpha-particle data (1969–1970) (Version 1) [Dataset]. Royal Belgian Institute for Space Aeronomy. https://doi.org/10.18758/40T59LOB
creator: Heynderickx, Daniel
  type: Person
  family name: Heynderickx
  given name: Daniel
  member of: Royal Belgian Institute for Space Aeronomy
creator: Kruglanski, Michel
  type: Person
  family name: Kruglanski
  given name: Michel
  member of: Royal Belgian Institute for Space Aeronomy
is funded by: Dataset generated in the framework of the ESA/ESTEC TREND-2 and TREND-3 studies (contract No 9828/92/NL/FM and 11711/95/NL/JG)

Dataset AZUR/EI-88
type: Distribution
description: The file includes 230,974 records and one header lines. Each record includes 35 fields: ### `cdf_epoch` (column 01) [CDF] Epoch, milliseconds since year 0 (proleptic Gregorian calendar with astronomical year numbering). ### `epoch` (column 02) Epoch in [RFC3339] format. ### `quality` (column 03) Original data quality flag (0: _good_; 1: _average_; 2: _bad_). ### `position_gei_x`, `position_gei_y`, `position_gei_z` (columns 04-06) Satellite position in Geocentric Equatorial Inertial (GEI) Cartesian coordinates (x, y, z), in km. ### `b_meas_bx`, `b_meas_by`, `b_meas_bz` (columns 07-09) Measured magnetic field components (x,y,z), in Gauss. ### `fpdu_1_1.5-2.7`, `fpdu_1_2.7-5.2`, `fpdu_1_5.2-10.4`, `fpdu_1_10.4-22.0`, `fpdu_1_22.4-48.8`, `fpdu_1_48.8-104.0` (columns 10-15) Differential directional proton fluxes measured by the telescope oriented perpendicular with respect to the local magnetic field vector, in cm⁻² s⁻¹ sr⁻¹ MeV⁻¹, for the six energy channels * 1.5 - 2.7 MeV * 2.7 - 5.2 MeV * 5.2 - 10.4 MeV * 10.4 - 22.0 MeV * 22.4 - 48.8 MeV * 48.8 - 104.0 MeV ### `fpdu_2_1.5-2.7`, `fpdu_2_2.7-5.2`, `fpdu_2_5.2-10.4`, `fpdu_2_10.4-22.0`, `fpdu_2_22.4-48.8`, `fpdu_2_48.8-104.0` (columns 16-21) Differential directional proton fluxes measured by the telescope oriented at 45° with respect to the local magnetic field vector (in the northern hemisphere, the telescope pointed upwards), in cm⁻² s⁻¹ sr⁻¹ MeV⁻¹, for the six energy channels * 1.5 - 2.7 MeV * 2.7 - 5.2 MeV * 5.2 - 10.4 MeV * 10.4 - 22.0 MeV * 22.4 - 48.8 MeV * 48.8 - 104.0 MeV ### `fadu_1_6.0-19.0` (column 22) Differential directional alpha flux measured by the 90° telescope, in cm⁻² s⁻¹ sr⁻¹ MeV⁻¹. Energy range: 6.0 - 19.0 MeV. ### `fadu_2_6.0-19.0` (column 23) Differential directional alpha flux measured by the 45° telescope, in cm⁻² s⁻¹ sr⁻¹ MeV⁻¹. Energy range: 6.0 - 19.0 MeV. ### UNILIB data (columns 24-35) Magnetic field related coordinates computed with [UNILIB] for both telescopes using a combination of the…
license: CC BY 4 0
media type: x-comma-separated-values
format: CSV
access URL: https://data.aeronomie.be/dataset/c6e07f22-b7b9-421c-858c-d3c991ffe6f7/resource/11fbc968-897f-42df-bd9c-ec1ea140c6ec/download/dataset_azur_ei_88.csv
issued: 2026-08-25T09:45:10.790998
modified: 2026-08-27T08:08:23.983989
byte size: 51215583

SPASE Metadata (NumericalData)
type: Distribution
description: Description of the data file structure in [SPASE] format [SPASE]: <https://doi.org/10.48322/E72C-5Y75> "Space Physics Archive Search and Extract (SPASE) Base Information Model, 2021, SPASE Group"
license: CC BY 4 0
media type: https://www.iana.org/assignments/media-types/text/xml
format: XML
access URL: https://data.aeronomie.be/dataset/c6e07f22-b7b9-421c-858c-d3c991ffe6f7/resource/b28e70f2-9a14-44f7-88d4-597135ed64e3/download/dataset_azur_ei_88.spase.xml
issued: 2026-08-26T15:34:43.790490
modified: 2026-08-27T08:09:24.969042
byte size: 21167