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Federal dataMaps & Geospatial
AM Index
Published by National Centers for Environmental Information · Updated 01/01/1948 · Monthly
- Last updated
- 01/01/1948
- First published 01/01/1948
- Update frequency
- Monthly
- Formats
- Web only
- Coverage
- Nationwide
- Federal data
About this dataset
Geomagnetic Range index using data from multiple observatories - Mayaud 1948
Files and access
Links open the official government source
- Global Change Master Directory (GCMD) Keywordsearthdata.nasa.govWeb page
Links open outside websites we do not control.
Frequently asked questions
- Who publishes AM Index?
- National Centers for Environmental Information, part of National Oceanic and Atmospheric Administration, Department of Commerce, publishes this dataset on Data.gov.
- How often is it updated?
- The publisher lists the update frequency as monthly. The last update was on 01/01/1948.
- How do I download it?
- Use the official source link above to view or request the data.
Similar data from other publishers
- Index MapState of Virginia · Prince William County1" = 5280' map shows the County 5K and 10K grid overlay. Recommended print size: 31" X 37". --- ### 🔗 Related Datasets - [Index Map](https://odgavaprod.ogopendata.com//dataset/9af341b2-d2c0-4375-884f-ab91949a6d13) - *Prince William County* ---ArcGIS RESTUpdated 06/12/2026
- Index MapState of Virginia · Prince William County1" = 5280' map shows the County 5K and 10K grid overlay. Recommended print size: 31" X 37". --- ### 🔗 Related Datasets - [Index Map](https://odgavaprod.ogopendata.com//dataset/e74d2a92-340c-44b9-93aa-de80dc2e19a9) - *Prince William County* - [Base Map](https:ArcGIS RESTUpdated 03/23/2026
- Photo IndexState of Virginia · Arlington County - GIS PortalThis map service contains historical aerial photograph index layers representing aerial imagery acquisition years from 1934 through 1989 for Arlington County, Virginia. Each index polygon identifies the footprint and reference information for individual aerialArcGIS RESTUpdated 10/02/2026
- Baist Index (1959)District of Columbia · DC Office of PlanningThe Baist Index provides a mapping index that mirrors the hardcopy index in the original Baist Map Volumes. The Index was hand digitized from the original Baist map volumes. Spatial data was attributed to enable selection of Map Volume as well as individual maCSVGeoJSONKMLZIP+2Updated 03/15/2002
- Photo Index 1969State of Virginia · Arlington County - GIS PortalThis map service contains historical aerial photograph index layers representing aerial imagery acquisition years from 1934 through 1989 for Arlington County, Virginia. Each index polygon identifies the footprint and reference information for individual aerialCSVZIPGeoJSONKML+5Updated 10/02/2026
Where this catalog comes from
- Data.gov CatalogU.S. General Services Administration
- State and local open data portalsSocrata Discovery API
- State and city CKAN portalsCalifornia, Virginia, Boston, Houston and more
- Government ArcGIS Hub sitesCity and county GIS data
Catalog checked 10/24/2026
We list dataset descriptions only. Downloads and APIs link straight to the official government source, which holds the current version and its terms of use.
Source: Data.gov · Last updated 10/24/2026 · Listing only; the data stays with the publisher
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