Ionospheric Digital Database

The ionosphere is that part of the Earth's atmosphere that results mainly from the photo ionization of the upper atmosphere. Traditionally, the following ionospheric regions and their approximate height ranges have been designated: D region (60-90 km); E region (90-150 km); F1 region (150-250 km); and F2 region (above 250 km). Ionosondes utilize the radio wave-reflecting properties of the ionosphere. The product of the speed of light in a vacuum and half the elapsed time between vertical transmission of a single frequency electromagnetic wave and reception of the reflected wave at the transmitting location is defined as the virtual height of that frequency. A sweep-frequency ionogram is a plot of virtual height versus frequency and is recorded as instantaneously as possible. These ionospheric data consist mainly of hourly values for at least one of the following characteristics: foF2, M(3000)F2, hF2, foF1, M(3000)F1, hF, foE, hE, foE2, hE2, foEs, fbEs, hEs, fmI, and fxI. The values are five byte (character) fields. The first three bytes of the field are reserved for a numeric value; the last two bytes are reserved for the qualifying and descriptive letter, if present. There are no decimals encoded in these data. Documentation is included. There are two CD-ROM's worth of data. One contains 1957 - 1975 data; the other contains 1976-1990 data. ASCII data files and a DOS-compatible application is included.

Data and Resources

Field Value
accessLevel public
accrualPeriodicity R/P1M
bureauCode {006:48}
catalog_@context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
catalog_conformsTo https://project-open-data.cio.gov/v1.1/schema
catalog_describedBy https://project-open-data.cio.gov/v1.1/schema/catalog.json
identifier gov.noaa.ngdc.stp.ionosonde:G01257
language {en-US}
modified 1981-01-01
old-spatial {"type": "Polygon", "coordinates": [[[-180.0, -90.0], [180.0, -90.0], [180.0, 90.0], [-180.0, 90.0], [-180.0, -90.0]]]}
programCode {006:059}
publisher DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce (Point of Contact)
resource-type Dataset
source_datajson_identifier true
source_hash fad6a33c65824eb9fd036086aaa7e2480319b994
source_schema_version 1.1
spatial {"type": "Polygon", "coordinates": [[[-180.0, -90.0], [180.0, -90.0], [180.0, 90.0], [-180.0, 90.0], [-180.0, -90.0]]]}
temporal 1957-01-01T00:00:00/1990-01-01T00:00:00
Groups
  • AmeriGEOSS
  • National Provider
  • North America
Tags
  • amerigeo
  • amerigeoss
  • boulder
  • boulder-world-data-center-for-solar-terrestrial-physics
  • ckan
  • doc-noaa-nesdis-ngdc-national-geophysical-data-center
  • earth-science-solar-physics-solar-energetic-particles-particle-density
  • geo
  • geoss
  • global
  • ionosonde
  • ionosphere
  • national
  • nesdis
  • noaa
  • north-america
  • space-physics-ionospheric-science
  • u-s-department-of-commerce
  • united-states
  • vertical-soundings
  • wdc-stp
isopen False
license_id notspecified
license_title License not specified
maintainer Justin Mabie
maintainer_email ionosonde@noaa.gov
metadata_created 2025-11-21T13:09:30.111972
metadata_modified 2025-11-21T13:09:30.111976
notes The ionosphere is that part of the Earth's atmosphere that results mainly from the photo ionization of the upper atmosphere. Traditionally, the following ionospheric regions and their approximate height ranges have been designated: D region (60-90 km); E region (90-150 km); F1 region (150-250 km); and F2 region (above 250 km). Ionosondes utilize the radio wave-reflecting properties of the ionosphere. The product of the speed of light in a vacuum and half the elapsed time between vertical transmission of a single frequency electromagnetic wave and reception of the reflected wave at the transmitting location is defined as the virtual height of that frequency. A sweep-frequency ionogram is a plot of virtual height versus frequency and is recorded as instantaneously as possible. These ionospheric data consist mainly of hourly values for at least one of the following characteristics: foF2, M(3000)F2, hF2, foF1, M(3000)F1, hF, foE, hE, foE2, hE2, foEs, fbEs, hEs, fmI, and fxI. The values are five byte (character) fields. The first three bytes of the field are reserved for a numeric value; the last two bytes are reserved for the qualifying and descriptive letter, if present. There are no decimals encoded in these data. Documentation is included. There are two CD-ROM's worth of data. One contains 1957 - 1975 data; the other contains 1976-1990 data. ASCII data files and a DOS-compatible application is included.
num_resources 1
num_tags 21
title Ionospheric Digital Database