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OpenTopography is an online archive and access portal for high-resolution topographic data from lidar, radar and photogrammetry. This guide is for researchers who need to know what the platform holds, who can download what, how its API keys and quotas work, and how to cite the data properly. Facts below come from the OpenTopography pages named under Sources, read on 2026-11-07.
What OpenTopography is
OpenTopography’s stated aim is to “expand efficient online access to high-resolution topographic data from lidar, radar, and photogrammetry.” Researchers use it to find point-cloud and raster elevation datasets and to retrieve them without hosting terabytes of source data themselves. If you need background on the products it serves, see the CASRAI guides on digital elevation models and remote sensing.
Who runs it and what it covers
OpenTopography is a collaboration of the San Diego Supercomputer Center at UC San Diego, the EarthScope Consortium, and the School of Earth and Space Exploration at Arizona State University. Core support comes from the US National Science Foundation Division of Earth Sciences (awards 2410799, 2410800 and 2410801). Datasets that are NSF-funded or sponsored are free to all users; some specialised federated datasets are reserved for academic users and subscribers to the OpenTopography+ (OT+) service.
Its Application Programming Interfaces expose several dataset families:
- Global Datasets API: SRTM (GL3 at 90 m, GL1 at 30 m, and GL1 ellipsoidal), COP30, COP90, ALOS World 3D, NASADEM and SRTM15+.
- USGS 3DEP Raster API: 1 m, 1/3 arc-second (about 10 m) and 1 arc-second (about 30 m) products.
- Point Elevation API: returns elevation at a point; it defaults to COP30.
- Data Catalog API, a STAC catalog and a CSW endpoint for searching dataset metadata programmatically.
How to find and use the data
The official pages describe the following entry points. The platform’s own documentation should be your guide for the exact options inside each job form.
- Find Topography Data map. The start page describes this map interface as the way to discover the complete list of topography datasets. A separate data catalog lists dataset metadata.
- Account. The portal has a My Account area; the sign-in is on the portal site. Registration status determines your limits (see the table below).
- API key. Keys are required for the Global Datasets and Point Elevation APIs, and the USGS 3DEP API uses the same free key. You request it from My Account. One user holds one key, and keys must not be shared or embedded in public code.
- API documentation. Interactive Swagger documentation is published at portal.opentopography.org/apidocs/.
- Learning materials. The Learn pages link Jupyter notebooks on GitHub covering PDAL, STAC, tile-index search and Cloud Optimized GeoTIFFs, plus training and workshops.
Access tiers and quotas
This is the practical question the portal’s landing page does not answer at a glance: what you are allowed to pull, and how much.
| Limit | Value stated by OpenTopography |
|---|---|
| Point-cloud job size, guest users | 50 million points |
| Point-cloud job size, registered non-academic users | 250 million points |
| Point-cloud job size, OT+ subscribers and academics | 350 million points (250 million for USGS and NOAA data) |
| Global Datasets API, per 24 hours (academic / non-academic) | 200 / 50 requests |
| USGS 3DEP API, per 24 hours (academic / non-academic) | 200 / 50 requests |
| Point Elevation API, per 24 hours (academic / non-academic) | 250 / 50 requests |
OT+ raises the limits for non-academic users, and an Enterprise key exists for intensive or commercial use (arranged through OpenTopography’s contact address on the developers page).
One restriction matters for planning: USGS 3DEP, NOAA Coastal Lidar, ArcticDEM and REMA are “only freely open to the U.S. academic research and education community due to funding limits.” US academics with a .edu email address can register for access. The same source data is also available free directly from USGS, NOAA and the Polar Geospatial Center.
Citing OpenTopography data
OpenTopography states: “As a condition of use, you must cite the use of OpenTopography data in your work with a formal citation.” Cite the dataset’s DOI and list it in your References. The recommended elements are author or organisation, year, title and version, collector, distributor (OpenTopography), DOI and access date. The dataset landing page and the job results page provide a ready citation. For wider practice, see the CASRAI entry on the data citation principle and on DataCite DOIs.
- USGS 3DEP and NOAA Coastal Lidar data have no DOIs. Cite the portal URL and compile the citation manually from the job page.
- Most data held by OpenTopography are government-funded and in the public domain, but some carry licences such as CC BY 4.0. You are responsible for complying with each dataset’s licence, and for attributing both the data source and OpenTopography.
- Acknowledge the OpenTopography Facility and its NSF awards, and check each dataset’s metadata for provider-specific credit lines.
Strengths and limits
Strengths
- One discovery interface and API layer across lidar, radar and photogrammetry products.
- Free access to NSF-sponsored datasets and to a free API key.
- Machine-readable catalog interfaces (STAC, CSW) and worked notebooks.
- Citation support, with dataset DOIs to cite where available.
Limits
- Job sizes and daily API requests are capped by account type.
- Some of the largest US federal datasets are free on the portal only to US academic users, though the originals remain available from the agencies.
- 3DEP and NOAA Coastal Lidar data lack DOIs, so citations take more manual work.
Alternatives and original sources
| Source | Relation to OpenTopography (per OpenTopography’s start page) |
|---|---|
| USGS (3DEP) | Same 3DEP data is available free directly from USGS |
| NOAA (Coastal Lidar) | Same data available free directly from NOAA |
| Polar Geospatial Center (ArcticDEM, REMA) | Same data available free directly from the PGC |
In the CASRAI taxonomy, OpenTopography is an example of a domain repository for geoscience data.
FAQ
Is OpenTopography free?
NSF-funded and sponsored datasets are free to all users. Some specialised datasets are reserved for academics and OT+ subscribers, and non-academic limits are lower.
Do I need an OpenTopography API key?
Yes for the Global Datasets and Point Elevation APIs, and the USGS 3DEP API uses the same free key. Request it from My Account in the portal.
Where can I download a DEM from OpenTopography?
Through the Find Topography Data map, or programmatically via the Global Datasets API (SRTM, COP30, COP90, ALOS World 3D, NASADEM, SRTM15+) and the 3DEP Raster API.
How do I cite OpenTopography data?
Cite the dataset DOI, as described under Citing OpenTopography data, and acknowledge the OpenTopography Facility and its NSF awards.
Sources
- OpenTopography, About: https://opentopography.org/about (read 2026-11-07)
- OpenTopography, Developers: https://opentopography.org/developers (read 2026-11-07)
- OpenTopography, Start: https://opentopography.org/start (read 2026-11-07)
- OpenTopography, Learn: https://opentopography.org/learn (read 2026-11-07)
- OpenTopography, Citations: https://opentopography.org/citations (read 2026-11-07)
