AGeoP-19 additional military layers, digital geospatial data products

What it is

AGeoP-19 is the NATO Allied Geographic Publication that defines Additional Military Layers (AML), described in the document itself as "a unified range of digital geospatial data products designed to satisfy the totality of NATO non-navigational maritime defence requirements" (1.2). It is a product-family specification and governance document, not a management-system standard: it describes what each AML product contains, how it is built and encoded, and who governs it, rather than setting quality-assurance requirements an auditor checks. AML supplements standard navigational charts such as ENC and DNC with additional vector and gridded data, built to give "the defence maritime user" the information to support situational awareness "at every operating level from strategic planning to tactical operation" (1.2), and to be deployable across systems from headquarters planning through to navigational, weapon and sensor systems.

Edition B, version 1 was promulgated in February 2022, effective on receipt, and supersedes Edition A, version 1, which nations are to destroy under their own procedures. It reaches NATO nations through STANAG 7170: "the agreement of nations to use this publication is recorded in STANAG 7170" (Letter of Promulgation). As with any STANAG-covered Allied Publication, this is a national ratification rather than an obligation on a private-sector supplier by default; a national hydrographic or defence geospatial organisation, or a contractor building a system for one, meets it because a contract, tender or WECDIS interoperability requirement calls for it.

What each AML product contains

AGeoP-19 does not carry the detailed content specification itself. That lives in the separately maintained AML Product Specifications, hosted on the UK Hydrographic Office's AML web page, which the document calls "the authority for AML products" (1.5) and which "must be referred and adhered to by any AML production or receiving system" (1.5). AGeoP-19 describes the product family around them: six vector layers from the original 2001 specification, Contour Line Bathymetry (depth data denser than a standard chart), Large and Small Bottom Objects (seabed contacts above and below 5 metres respectively), Environment, Seabed and Beach (sediment, slope and beach data for mine-countermeasure and amphibious planning), Routes, Areas and Limits (territorial waters, practice areas, transit lanes) and Maritime Foundation and Facilities (coastline, ports, lights, pipelines and other background features); plus three gridded layers added between 2004 and 2006, Integrated Water Column and Atmospheric and Meteorological Climatology, and the still-draft Gridded Sediment product, which the document flags plainly as "not endorsed by NATO however it is used by some nations" (1.6). Version 3.0, published in 2008, folded the six vector specifications into one and extended their content with land, ice and air features and additional attribution.

Format, datum and an explicit no-encryption rule

Every AML product uses the WGS84 horizontal datum, and the only NATO-endorsed exchange format for the vector layers is IHO S-57, with gridded products delivered in netCDF or GRIB. The specification is deliberately split into a content part and separate format annexes, to keep the data's meaning stable while allowing flexibility in how it is encoded. Two requirements are easy to miss: "in the interests of international interoperability, AML products will not be encrypted" (1.11), unlike the S-63 scheme used for navigational ENC data, and the terms "Additional Military Layers" and "AML" are reserved exclusively for the concept and products this publication identifies (1.2), so the labels cannot be reused loosely.

Three concurrent versions, one national choice

Versions 1.0, 2.1 and 3.0 of the vector specification remain concurrently current because, in the document's own words, "the version of AML a NATO nation chooses to adopt will be dictated by the capability of their AML receiving systems and the requirements for interoperability across warfare disciplines and between NATO nations and NATO commands" (1.9). That choice genuinely varies: the recorded national reservations show Estonia still working toward producing some layers depending on data availability, Lithuania using only what it has already developed with no near-term plans to extend, Romania holding the equipment to compile six vector products but lacking WECDIS-equipped warships to use them, and the United States not participating in AML co-production at all while it transitions its own charting production toward the S-57-based standard AML depends on.

Where AML sits in NATO's wider geospatial programme

AML is "recognised as a core requirement for NATO maritime geospatial requirements" (1.10) and is "a mandated product for WECDIS as defined in STANAG 4564" (1.10), the shipboard electronic charting system used across NATO navies, and is supported through the multinational NATO AML Co-Production Programme. Development is directed by the Geospatial Maritime Working Group, which reports annually to the NATO Geospatial Board and is directed and supported for standardization work by the Joint Geospatial Standards Working Group. A next generation, AML+, built on the IHO S-500 series within the wider Defence Maritime Geospatial Exchange Model that STANAG 6503 outlines, is already in development; the document notes that STANAG 6503 will, "in due course," supersede STANAG 7170 (1.13), meaning the agreement that currently carries AGeoP-19 is itself expected to be replaced as that work matures. Separately, a planned Network Model Bathymetry specification was never completed; the document points implementers to the IHO S-102 Product Specification instead (1.12).

Standards it references

AGeoP-19 is carried by STANAG 7170, the NATO Standardization Agreement recording nations' agreement to use it. Within the text it also names APP-06, used together with IHO S-52 as the basis for the AML Portrayal Specification's display symbology; STANAG 4564, which defines WECDIS and mandates AML for it; and STANAG 6503, which outlines the Defence Maritime Geospatial Exchange Model that AGeoP-19's planned successor, AML+, is being built within. It also notes that the AML Large Bottom Object layer historically superseded former STANAG 3715, a document outside our catalogue, and names several IHO publications the format builds on or is moving toward, S-57, S-52, S-100, S-102 and the emerging S-500 series, which likewise sit outside the NATO catalogue.

Standards it references

• APP-06Background
• STANAG 4564Background
• STANAG 6503Background