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ESRI ASCII Grid (.asc)

Open Beta

.asc · text/plain

ESRI ASCII Grid is the common text format for an ELEVATION GRID: a six-line header (NCOLS, NROWS, XLLCORNER, YLLCORNER, CELLSIZE, NODATA_VALUE) followed by space-separated numbers. Every cell value IS the elevation in METRES above sea level with one decimal — not a colour, not a shadow, not an image pixel. Heights come from the global Copernicus DEM GLO-30: about a 30 m step, vertical accuracy ~2–4 m. The grid is clipped exactly to the area you ordered, written in the coordinate system you chose, and empty cells carry NODATA_value -9999. Delivery is a ZIP holding exactly two files: map.asc and map.prj with the coordinate system (the .asc itself has nowhere to declare it). An honest caveat: over the sea GLO-30 returns exactly 0 m rather than emptiness — that is the behaviour of the elevation source, not a fault of the export. Text is bulkier than a binary raster, so the grid has a ceiling of 4 million cells: a larger area is coarsened just enough to fit, and the new step is stated as a number. It opens in a plain text editor, ArcGIS, QGIS, GRASS, GDAL, R, rasterio, Surfer and Civil 3D. This is pre-design, GIS and visualisation — not a land survey.

ఇప్పుడే ASCII Grid ఎగుమతి చేయండి ✨ ఓపెన్ బీటా — ఉచితం, పరిమితులు లేవు

ముఖ్య లక్షణాలు

✓The cell value is the elevation in metres with one decimal — no palette, no rescaling

✓Heights from Copernicus DEM GLO-30: about a 30 m step, vertical accuracy ~2–4 m

✓Clipped exactly to the ordered area — not to a degree tile and not to a map tile

✓NODATA_value -9999 for cells without elevation; the empty share is stated as a number

✓Exactly two files in the archive: map.asc and map.prj with the coordinate system you chose

Example ASCII Grid export (central Moscow, 1x0.5 km) — Example: central Moscow, ~1×0.5 km, medium detail

ASCII Grid ఫార్మాట్ గురించి

ESRI ASCII Grid is the simplest of the raster formats: six header lines (the number of columns and rows, the coordinates of the lower left corner, the cell size, the NODATA value) and then a grid of numbers separated by spaces. The file reads in any text editor and is parsed by five lines of code in any language, which is why it is still used in academic pipelines and for long-term storage.

The format is chosen when what matters is not efficiency but portability and transparency: a supplement to an article, a dataset in a repository, an input grid for GRASS, R or rasterio, an exchange with a colleague who has no GIS. Everything in the file is visible to the eye — nothing is hidden in a binary structure.

The output is a ZIP archive with two files: map.asc with the grid of values and map.prj with the description of the coordinate system. It is done that way because the .asc itself does not store the projection, and without it a GIS will not put the grid in its place. The cells hold ELEVATIONS in metres above sea level with one decimal: a clip of the global Copernicus DEM GLO-30 exactly to the area you ordered, about a 30 m step, vertical accuracy ~2-4 m; cells without coverage get -9999. Over the sea the source returns exactly 0 m rather than emptiness — that is how it behaves, and we do not hide it.

ASCII Grid ఫైళ్లను ఏ ప్రోగ్రామ్ తెరుస్తుంది

OSM2CDR నుండి ఎగుమతి చేసిన ESRI ASCII Grid (.asc) (.asc) ఫైళ్లను కింది ప్రోగ్రామ్‌లు మరియు అప్లికేషన్‌లు తెరవగలవు, సవరించగలవు మరియు వాటితో పని చేయగలవు:

🌎QGIS 🌎ArcGIS 💻GDAL / OGR 🌎GRASS GIS 💻Surfer 💻Python rasterio 📐R (raster package)

Format specifications

Open standard
3D coordinates supported
Lossless (no quality loss)
No attributes
Output: 2 files in archive
A ZIP with exactly two files: map.asc (six-line AAIGrid header plus cell values that ARE elevation in metres, one decimal, NODATA_value -9999) and map.prj with the coordinate system; heights from Copernicus DEM GLO-30 (~30 m cell, vertical accuracy ~2-4 m), 0 m over the sea because that is what the source returns.

ASCII Grid మ్యాప్‌లను ఎవరు ఉపయోగిస్తారు

🏗

Downloading the elevation grid of a site as text a colleague can open without special software — even in Notepad++

An elevation file that opens absolutely everywhere — down to a plain notepad, with no GIS installed.

💻

An input for terrain analysis in GRASS, R, rasterio or Surfer: slopes, catchment, profile, visibility

An input grid for computations in GRASS, R or rasterio, where AAIGrid is exactly what is expected.

📊

Importing the surface into Civil 3D, Global Mapper and older GIS packages that expect .asc

A surface for Civil 3D and Global Mapper: both import .asc directly.

🎨

Exchange and archival of elevations in a maximally portable text form (Zenodo, Dryad)

Long-term storage and publication: text survives changes of program versions better than binary formats.

ASCII Grid ను ఎలా ఎగుమతి చేయాలి

ప్రాంతాన్ని ఎంచుకోండి

osm2cdr.ru లోని ఇంటరాక్టివ్ మ్యాప్‌పై ఒక దీర్ఘచతురస్రం లేదా బహుభుజిని గీయండి

ASCII Grid ను ఎంచుకోండి

అందుబాటులో ఉన్న 127 ఎగుమతి ఫార్మాట్‌ల జాబితా నుండి ESRI ASCII Grid (.asc) ను ఎంచుకోండి

ఎగుమతి

'ఎగుమతి' క్లిక్ చేసి మీ .asc ఫైల్‌ను 1-5 నిమిషాల్లో అందుకోండి

డౌన్‌లోడ్

సిద్ధంగా ఉన్న ASCII Grid ఫైల్‌ను డౌన్‌లోడ్ చేసి దానిని QGIS లో తెరవండి

ఎగుమతి తర్వాత ఎలా తెరవాలి

Unpack the archive — keep map.asc and map.prj in the same folder and with the same name, otherwise the GIS will not find the coordinate system.
QGIS — Layer → Add Raster Layer → pick the .asc; the grid lands in its place, because the extent and the cell size are written in the header.
GDAL — gdalinfo map.asc shows the header and the extent, and gdal_translate converts the grid into GeoTIFF if you need a compact binary version.
R and Python — terra::rast() or rasterio.open() read the format directly; if you like, the grid can be loaded with plain numpy, skipping the six header lines.
A text editor — Notepad++ or any other will open the file to check the header; for large areas pick an editor that handles big files.

ASCII Grid లో జనాదరణ పొందిన మ్యాప్‌లు

ఉచితం