NMEA 0183 — Southern and Eastern Hemisphere Indicators
NMEA never writes a negative coordinate: sign lives entirely in the N/S and E/W letters, and the numeric field is always positive. This log sits in the southern and eastern hemispheres, so a parser that ignores the hemisphere letter puts every fix in the wrong quadrant of the world.
$GPGGA,120000.00,4703.8414,S,17831.0795,E,1,08,0.9,12.1,M,49.0,M,,*42
$GPRMC,120000.00,A,4703.8414,S,17831.0795,E,2.10,203.5,010126,,,A*7D
$GPGSA,A,3,03,07,11,18,22,25,29,31,,,,,1.8,0.9,1.5*35
$GPVTG,203.5,T,,M,2.10,N,3.89,K,A*08
$GPGGA,120015.00,4703.9709,S,17831.3148,E,1,08,0.9,18.9,M,49.0,M,,*4F
$GPRMC,120015.00,A,4703.9709,S,17831.3148,E,2.10,203.5,010126,,,A*72
$GPGSA,A,3,03,07,11,18,22,25,29,31,,,,,1.8,0.9,1.5*35
$GPVTG,203.5,T,,M,2.10,N,3.89,K,A*08
$GPGGA,120030.00,4704.0978,S,17831.5488,E,1,08,0.9,24.8,M,49.0,M,,*4F
$GPRMC,120030.00,A,4704.0978,S,17831.5488,E,2.10,203.5,010126,,,A*7C
$GPGSA,A,3,03,07,11,18,22,25,29,31,,,,,1.8,0.9,1.5*35
$GPVTG,203.5,T,,M,2.10,N,3.89,K,A*08
$GPGGA,120045.00,4704.2323,S,17831.7839,E,1,08,0.9,30.5,M,49.0,M,,*47
$GPRMC,120045.00,A,4704.2323,S,17831.7839,E,2.10,203.5,010126,,,A*7C
$GPGSA,A,3,03,07,11,18,22,25,29,31,,,,,1.8,0.9,1.5*35
$GPVTG,203.5,T,,M,2.10,N,3.89,K,A*08
$GPGGA,120100.00,4704.3588,S,17832.0143,E,1,08,0.9,36.7,M,49.0,M,,*45
$GPRMC,120100.00,A,4704.3588,S,17832.0143,E,2.10,203.5,010126,,,A*7A
$GPGSA,A,3,03,07,11,18,22,25,29,31,,,,,1.8,0.9,1.5*35
$GPVTG,203.5,T,,M,2.10,N,3.89,K,A*08
$GPGGA,120115.00,4704.4911,S,17832.2507,E,1,08,0.9,41.5,M,49.0,M,,*4E
$GPRMC,120115.00,A,4704.4911,S,17832.2507,E,2.10,203.5,010126,,,A*73
$GPGSA,A,3,03,07,11,18,22,25,29,31,,,,,1.8,0.9,1.5*35
$GPVTG,203.5,T,,M,2.10,N,3.89,K,A*08
$GPGGA,120130.00,4704.6222,S,17832.4848,E,1,08,0.9,46.1,M,49.0,M,,*43
$GPRMC,120130.00,A,4704.6222,S,17832.4848,E,2.10,203.5,010126,,,A*7D
$GPGSA,A,3,03,07,11,18,22,25,29,31,,,,,1.8,0.9,1.5*35
$GPVTG,203.5,T,,M,2.10,N,3.89,K,A*08
$GPGGA,120145.00,4704.7483,S,17832.7192,E,1,08,0.9,49.4,M,49.0,M,,*4A
$GPRMC,120145.00,A,4704.7483,S,17832.7192,E,2.10,203.5,010126,,,A*7E
$GPGSA,A,3,03,07,11,18,22,25,29,31,,,,,1.8,0.9,1.5*35
$GPVTG,203.5,T,,M,2.10,N,3.89,K,A*08
Specifications
- Format
- NMEA 0183
- Talker
- GP (GPS)
- Crs
- WGS 84 (EPSG:4326)
- Encoding
- ASCII
- Checksum Algorithm
- XOR of bytes between $ and *
- Date
- 2026-01-01
- Seed
- 20260807
- Sentences
- 32
- Latitude Hemisphere
- S
- Longitude Hemisphere
- E
- Sign Convention
- hemisphere letter, not a minus sign
- Line Endings
- CRLF (per NMEA 0183)
- All Checksums Valid
- true
Testing contract
Expected to pass- Scenario
- Parse the log into signed decimal degrees.
- Expected result
- Latitudes come out negative and longitudes positive; a parser that drops the hemisphere letters produces the mirror image of the true track.
What is a .nmea file?
An .nmea file is a log of NMEA 0183 sentences, the ASCII protocol GPS and marine electronics use. Each line begins with `$` and a five-character talker-and-type identifier such as GPGGA, GPRMC, or GPGSV, carries comma-separated fields, and ends with `*` and a two-digit XOR checksum. Positions are encoded as degrees-and-decimal-minutes with a separate hemisphere field, not as decimal degrees.
How to use this file
Use an example .nmea file to test GPS log parsers and track converters, verifying checksum validation, correct degrees-minutes-to-decimal conversion, and sensible handling of sentences emitted before a fix is acquired.
How to use this file for testing
“NMEA 0183 — Southern and Eastern Hemisphere Indicators” is a deterministic Novus Examples fixture for Geospatial, Error handling, Conversion testing. GeoJSON, GPX, and KML files with points, lines, polygons, and tracks — for testing map tools, route parsers, and geo importers.
Documented properties for this file: seed 20260807 · ASCII · CRLF (per NMEA 0183). Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.
Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such — expect parsers to fail loudly rather than silently accept them.
Geospatial fixtures publish one invented territory across formats, with the coordinate reference system and feature counts documented in specs. Convert or reproject and diff against the twin in the same group; edge-case geometries state exactly which assumption they are built to break.
Related files
- geojsonGeoJSON — Antimeridian Line Split per RFC 7946The same transect cut at the 180th meridian into a two-part MultiLineString, which is what RFC 7946 section 3.1.9 recommends. The split latitude is the linear interpolation of the unsplit twin, so the two files describe the same ground path.
- geojsonGeoJSON — Antimeridian Polygon Split into a MultiPolygonThe straddling block cut at 180 into two polygons that share an edge on the meridian — the interoperable form. Use it as the expected output when testing an antimeridian-splitting routine against the unsplit twin.
- geojsonGeoJSON — Clockwise Exterior Ring (right-hand rule violated)Both rings of the Mill Court parcel are wound the wrong way round: the exterior clockwise, the interior counter-clockwise. RFC 7946 mandates the right-hand rule, and consumers that rely on winding to tell holes from shells will read this polygon inside out.
- geojsonGeoJSON — Intentionally Invalid: Hole Outside Its ShellIntentionally invalid: the second ring is a whole separate parcel filed as an interior ring of the first, which OGC Simple Features forbids. It is what happens when a MultiPolygon is flattened into a Polygon by concatenating rings.
- geojsonGeoJSON — Intentionally Invalid: Latitude Before LongitudeIntentionally invalid: the five towns with their coordinates written latitude-first. RFC 7946 fixes the order as longitude then latitude, and this is the mistake that arrives via an EPSG-URN-ordered source such as the GML twin in the territory subcategory.
- geojsonGeoJSON — Intentionally Invalid: Self-Intersecting RingIntentionally invalid: a bowtie ring whose two lobes wind in opposite directions, so the shoelace areas nearly cancel. Buffer, intersection and area operations on this geometry return nonsense rather than failing, which is why it belongs in a validation suite.
Generated by generation/geospatial.py. Free for any use, no attribution required — license.