SunreachTHE PEOPLE & DATA BEHIND SUNREACH
Every ridge.
Every source.
Properly credited.
Before we can follow the light, someone has to measure the mountains. These are the mapping agencies, open-data communities and photographers whose work makes Sunreach possible.
01 / THE SHAPE OF THE LAND
A global foundation.
A closer look, where available.
The app combines global elevation with finer national data. Ground models describe the land itself, and that is what the app uses: trees and buildings are not counted for now.
Coverage is specific to the data available at your pin. Sunreach falls back to global terrain where fine data is missing.
Read the method and accuracy limits ↗Terrain Tiles
Tilezen / Mapzen · hosted through AWS Open Data
Elevation tiles form the broad landscape around your spot. Sunreach resamples them to a 40 m grid covering 50 × 50 km and uses them to calculate the distant skyline.
Terrain Tiles combine several regional datasets. AWS hosts the tiles; the original producers retain their own source credits and terms.
Diagram for explanation; not a measured landscape.
All regional credits in the global terrain collection
- Arctic
- ArcticDEM · DigitalGlobe imagery; NSF awards 1043681, 1559691 and 1542736
- Australia
- © Commonwealth of Australia (Geoscience Australia), 2017
- Austria
- © offene Daten Österreichs · Digitales Geländemodell (DGM) Österreich
- Canada
- Information licensed under the Open Government Licence – Canada
- Europe
- Produced using Copernicus data and information funded by the European Union – EU-DEM layers
- Global ocean relief
- ETOPO1 · U.S. National Oceanic and Atmospheric Administration
- Mexico
- INEGI · Continental relief, 2016
- New Zealand
- Copyright 2011 Crown copyright · Land Information New Zealand and the New Zealand Government. All rights reserved.
- Norway
- © Kartverket
- United Kingdom
- © Environment Agency copyright and/or database right, 2015. All rights reserved.
- United States + global
- 3DEP, GMTED2010 and SRTM · courtesy of the U.S. Geological Survey
Regional sources and terms follow the Terrain Tiles maintainer’s attribution list. The providers contributing to a tile depend on its location.
Closer to the ground
2 m models in supported areas · current app coverage
Slovenia
Laser scanning of Slovenia · 2011–2015
Slovenian Environment Agency
CC BY 4.0 ↗- Data layers
- DMR1 bare ground
- Current coverage
- 2 m ground model within 2 km in the bundled Velika korita Soče and Ihan areas; wider coverage requires additional hosted sheets.
- What we change
- The ground model is processed into 2 m sheets.
- Source dates
- 2011–2015 acquisition programme.
Slovenian Environment Agency (ARSO), Laser scanning of Slovenia 2011–2015, CC BY 4.0
France
LiDAR HD · MNT
Institut national de l’information géographique et forestière
Licence Ouverte 2.0 ↗- Data layers
- MNT bare ground
- Current coverage
- 2 m ground model from IGN LiDAR HD where processed sheets are available in metropolitan France and Corsica; coverage depends on published source data and available sheets.
- What we change
- Source 1 m ground rasters are resampled to 2 m and processed into sheets for the app’s terrain calculations.
- Source dates
- Acquisition and update dates vary by source tile. Follow the IGN catalogue and source metadata for the reused information’s dates.
IGN, LiDAR HD, Licence Ouverte 2.0
Austria
Airborne laser scanning · DTM
Bundesamt für Eich- und Vermessungswesen
CC BY 4.0 ↗- Data layers
- DTM bare ground
- Current coverage
- 2 m ground model from BEV airborne laser scanning where processed sheets are available; coverage depends on available sheets.
- What we change
- BEV’s 1 m ground rasters are resampled and processed into 2 m sheets. The source is a cooperative product of federal and state mapping providers.
- Source dates
- Dates vary by tile. A mosaic reference date is not the date the ground was surveyed.
© BEV – Bundesamt für Eich- und Vermessungswesen, CC BY 4.0
Switzerland & Liechtenstein
swissALTI3D
Federal Office of Topography
Free use with source credit ↗- Data layers
- swissALTI3D bare ground
- Current coverage
- 2 m ground model (swissALTI3D) fetched from swisstopo for spots in Switzerland and Liechtenstein.
- What we change
- The 2 m versions of swisstopo’s 1 km tiles are read on demand and cached.
- Source dates
- Tile years differ; the newest flight per tile is used.
© swisstopo (Federal Office of Topography), swissALTI3D and swissSURFACE3D
Spain
MDT05 · from PNOA-LiDAR
Instituto Geográfico Nacional
CC BY 4.0 ↗- Data layers
- 5 m bare ground (MDT05)
- Current coverage
- 5 m ground model (IGN MDT05, from PNOA lidar) fetched for spots in mainland Spain and the Balearic and Canary Islands.
- What we change
- The 5 m ground model is requested per square kilometre from IGN’s coverage service and interpolated to the app’s 2 m grid. No surface model is used.
- Source dates
- Derived from the PNOA lidar coverages; flight years vary by region.
© Instituto Geográfico Nacional (IGN), MDT05 from PNOA-LiDAR, CC BY 4.0 (scne.es)
Germany
Digitales Geländemodell 1 m · DGM1
State surveying offices (Bayern, Baden-Württemberg, Nordrhein-Westfalen, Sachsen-Anhalt)
CC BY 4.0 · dl-de/by-2-0 · dl-de/zero-2-0 ↗- Data layers
- 1 m bare ground (DGM1)
- Current coverage
- 2 m ground models from the 1 m state terrain models (DGM1) of Bavaria, Baden-Württemberg, North Rhine-Westphalia and Saxony-Anhalt; other states use global terrain for now.
- What we change
- Each state’s 1 m ground model is fetched per square kilometre and averaged to 2 m. No surface model is used.
- Source dates
- Each state renews its laser scan on its own schedule; dates vary by tile.
© Bayerische Vermessungsverwaltung, DGM1, CC BY 4.0 · © LGL, www.lgl-bw.de, DGM1, dl-de/by-2-0 · © Geobasis NRW, DGM1, dl-de/zero-2-0 · © GeoBasis-DE / LVermGeo ST, DGM1, dl-de/by-2-0
Italy · Trentino
LiDAR PAT 2014 integrated with 2018 flights
Provincia autonoma di Trento
CC BY 4.0 ↗- Data layers
- DTM bare ground
- Current coverage
- 2 m ground model from the Province of Trento’s lidar in the bundled Pale di San Martino area (Baita Segantini); the rest of Trentino, Valle d’Aosta and Friuli Venezia Giulia require additional processed sheets.
- What we change
- The 0.5 m ground model is averaged into 2 m sheets.
- Source dates
- 2014 survey, integrated with 2018 flights.
© Provincia autonoma di Trento, LiDAR PAT 2014–2018, CC BY 4.0
Netherlands
Actueel Hoogtebestand Nederland · AHN4 DTM
Rijkswaterstaat and Het Waterschapshuis
CC0 ↗- Data layers
- 0.5 m bare ground (AHN4 DTM)
- Current coverage
- 2 m ground model from AHN4 (0.5 m lidar), fetched for spots anywhere in the Netherlands.
- What we change
- PDOK’s coverage service cuts each square kilometre to 2 m in the app’s grid. Water has no heights in AHN and falls back to global terrain.
- Source dates
- AHN4 was flown 2020–2022.
AHN4, © Rijkswaterstaat and Het Waterschapshuis, CC0
Belgium · Flanders
Digitaal Hoogtemodel Vlaanderen II · DTM 1 m
Digitaal Vlaanderen
Modellicentie Gratis Hergebruik ↗- Data layers
- 1 m bare ground (DTM)
- Current coverage
- 2 m ground model from the Digital Elevation Model of Flanders II (1 m lidar), fetched for spots in Flanders; Brussels and Wallonia use global terrain for now.
- What we change
- The 1 m ground model is requested per square kilometre from Digitaal Vlaanderen’s coverage service and resampled to 2 m.
- Source dates
- Flown 2013–2015.
DHMV II DTM 1 m (2013–15). Bron: Digitaal Vlaanderen, Modellicentie Gratis Hergebruik
Czechia
DMR 5G · digital terrain model, 5th generation
Czech Office for Surveying, Mapping and Cadastre
CC BY 4.0 ↗- Data layers
- Bare ground (DMR 5G)
- Current coverage
- 2 m ground model (ČÚZK DMR 5G, from lidar), fetched for spots anywhere in Czechia.
- What we change
- The model is read per square kilometre from ČÚZK’s image service at 2 m in the app’s grid.
- Source dates
- Laser scanning 2009–2013.
DMR 5G (2009–13), © ČÚZK, CC BY 4.0
Poland
NMT · numeryczny model terenu, 1 m
Główny Urząd Geodezji i Kartografii
Free for any use ↗- Data layers
- 1 m bare ground (NMT)
- Current coverage
- 2 m ground model from GUGiK’s 1 m lidar terrain model (NMT), fetched for spots anywhere in Poland.
- What we change
- The 1 m ground model is requested per square kilometre from the geoportal’s coverage service and resampled to 2 m.
- Source dates
- Laser scanning dates vary by region.
NMT 1 m, © GUGiK, free for any use
Norway
Nasjonal høydemodell · DTM 1 m
Kartverket
CC BY 4.0 ↗- Data layers
- 1 m bare ground (DTM)
- Current coverage
- 2 m ground model from Kartverket’s 1 m national lidar terrain model, fetched for spots anywhere in mainland Norway.
- What we change
- The 1 m ground model is requested per square kilometre from Kartverket’s coverage service and resampled to 2 m.
- Source dates
- National laser scanning programme, completed 2022.
NHM DTM 1 m, © Kartverket, CC BY 4.0
Finland
Elevation model 2 m · 2018
National Land Survey of Finland
CC BY 4.0 ↗- Data layers
- 2 m bare ground
- Current coverage
- 2 m ground model from the National Land Survey of Finland’s 2 m elevation model, fetched for spots anywhere in Finland.
- What we change
- The 2 m model is read per square kilometre from CSC’s Paituli coverage service.
- Source dates
- 2018 edition of the elevation model.
Contains data from the National Land Survey of Finland, elevation model 2 m, 2018, CC BY 4.0, via CSC Paituli
Estonia
Digital terrain model · 1 m
Maa- ja Ruumiamet (Land and Spatial Development Board)
Maa- ja Ruumiamet open data licence ↗- Data layers
- 1 m bare ground (DTM)
- Current coverage
- 2 m ground model from Maa- ja Ruumiamet’s 1 m lidar terrain model, fetched for spots anywhere in Estonia.
- What we change
- The 1 m ground model is requested per square kilometre from the agency’s coverage service and resampled to 2 m.
- Source dates
- Laser scanning dates vary by area.
Kõrgusandmed (elevation data), Maa- ja Ruumiamet, open data licence
United States
3D Elevation Program · 3DEP
U.S. Geological Survey
Public domain ↗- Data layers
- High-resolution ground
- Current coverage
- 2 m ground models within 2 km where USGS 3DEP has suitable high-resolution coverage.
- What we change
- Ground elevations are requested on a 2 m grid. The app identifies the source survey.
- Source dates
- Survey dates vary by location; a finer output grid does not guarantee the same source resolution everywhere.
Map services and data available from U.S. Geological Survey, National Geospatial Program. USGS 3D Elevation Program (3DEP).
02 / CONTEXT FOR THE PLAN
The map. The names. The sky.
These services support the iPhone app. The website’s opening scene uses locally stored terrain and computed sun positions.
Mapbox
© Mapbox © OpenStreetMap. The app’s home map uses Mapbox’s Standard style, lit for the sun at your spot and minute, the 3D city view uses Mapbox’s buildings and landmarks, and with the Mapbox style the 3D terrain is draped with Mapbox’s map. The Mapbox logo and attribution (with “Improve this map”) stay on screen wherever Mapbox’s map shows.
Mapbox attribution ↗ Terms ↗Apple Maps
MapKit supplies place search and the Apple map and satellite styles, including the map draped over the 3D terrain when an Apple style is chosen. Apple Maps credits remain visible with its imagery, including within screenshots.
Apple Maps terms ↗OpenStreetMap
© OpenStreetMap contributors. Selected place and peak labels in the app come from the OpenStreetMap community. OpenStreetMap data is available under the Open Database Licence (ODbL).
Contributors & licence ↗Apple Weather
The app uses WeatherKit for forecasts. Its Apple Weather mark and provider attribution link appear alongside weather data. The homepage animation is a clear-sky calculation, not a forecast.
Apple Weather data sources ↗NOAA SWPC and GFZ Potsdam
Data: NOAA Space Weather Prediction Center (the OVATION aurora nowcast, planetary Kp and its forecast, real-time solar wind, WSA-ENLIL and the 27-day outlook; US government work, public domain). Hp30: GFZ German Research Centre for Geosciences, Potsdam, CC BY 4.0. Credited on the app’s aurora screen.
NOAA SWPC ↗ GFZ Kp and Hp30 ↗03 / THROUGH SOMEONE ELSE’S LENS
The photographers.
A place deserves a real photograph—and the person behind it deserves a credit. Each image carries its credit where it appears. The thumbnails here are cropped for display; the linked originals preserve the full frame.
CC BY-SA 3.0 · 2017-05-08
Resized and re-compressed.
CC BY-SA 4.0 · 2024-08-03
Resized and re-compressed.
CC BY-SA 4.0 · 2025-10-02
Resized and re-compressed.
CC BY-SA 3.0 · 2018-08-26
Resized and re-compressed.
.jpg){kind=link}
Resized and re-compressed.
CC BY 4.0 · 2015-09-25
Resized and re-compressed.
CC BY-SA 4.0 · 2017-10-21
Resized and re-compressed.
.jpg){kind=link}
CC BY 2.0 · 11 July 2014
Resized and re-compressed.
.jpg){kind=link}
CC0 · 2017-05-08
Resized and re-compressed.
Public domain · 2005-01-18
Resized and re-compressed.
CC BY-SA 4.0 · Taken on 9
Resized and re-compressed.
CC BY-SA 3.0 · 2013-12-28
Resized and re-compressed.
CC BY-SA 3.0 · 2011-07-31
Resized and re-compressed.
CC BY-SA 4.0 · 2020-06-22
Resized and re-compressed.
CC BY-SA 3.0 · 2017-10-08
Resized and re-compressed.
CC BY-SA 4.0 · 2021-10-17
Resized and re-compressed.
_06.jpg){kind=link}
CC BY-SA 4.0 · 2019-09-20
Resized and re-compressed.
CC BY-SA 4.0 · Taken on 2
Resized and re-compressed.
CC BY-SA 3.0 · 2013-09-22
Resized and re-compressed.
CC BY-SA 3.0 US · 2009-02-01
Resized and re-compressed.
CC BY-SA 4.0 · Taken on 8
Resized and re-compressed.
CC BY-SA 4.0 · Taken on 2
Resized and re-compressed.
CC BY-SA 4.0 · 2018-08-18
Resized and re-compressed.
CC BY-SA 4.0 · 2026-04-29
Resized and re-compressed.
CC0 · Taken on 2
Resized and re-compressed.
CC BY-SA 4.0 · 2021-04-10
Resized and re-compressed.
CC BY-SA 4.0 · 2024-01-23
Resized and re-compressed.
CC BY-SA 4.0 · Taken on 1
Resized and re-compressed.
CC BY-SA 4.0 · Taken on 7
Resized and re-compressed.
CC BY-SA 4.0 · 2024-04-24
Resized and re-compressed.
Full image register, original sizes and pages using each photo ↗
CC BY-SA photographs remain under their stated share-alike licence; that licence does not apply to the entire website. App screenshots and generated explanatory banners are made by Sunreach.
04 / BUILT ON OPEN WORK
A little help
drawing the light.
Three.js
The homepage terrain story and interactive demo use a locally hosted copy of Three.js r128 and its OrbitControls, by the Three.js authors, under the MIT licence. The original copyright and permission notice ships with the site.
The Sunreach engine
Sun positions and direct-light windows are calculated by our own engine, using the NOAA/Meeus solar equations and a terrain skyline. The 3D landscape is simplified; the Yosemite viewpoint times use a separate 2 m USGS ground calculation.
Understand the Yosemite example ↗