Contour lines with "Artefacts" near a vertical line situated at W0° 00' 00"
Hello, After many hours of time to get a correct knowledge of the most important tools needed to produce Garmin map, like mkmap, Splitter.. and plenty of hours to develop my own Styles files for mkgmap, I am now able to produce local maps mainly for Fenix 6x or Garmin 66, specifically for Trail Running. That help me also to have a mean to verify immediately all my contributions to OSM database. To have the best results for my personal maps, I use altitude data from Sonny. https://data.europa.eu/data/datasets/dtm-europe?locale=en For flat part of the country, I generally generate contour lines with a 5m space, in lieu of a 10m or 20m space between contours lines. That choice seems for me a very good choice for as an example "Ile de France" (Extended Region around Paris), where max altitude are between 150 to 200m. I recently generate contourlines near La Rochelle in France for a local zone called "Poitou-Charentes", http://download.geofabrik.de/europe/france/poitou-charentes.html but unfortunately, I have artefacts, that I don't have for example in many other regions of France. These artefacts are also visible for 5m, 10m and 20m space between contours lines. These "artefacts" are described in the pdf files given at this link: https://drive.google.com/file/d/1uiA51R4Kd_WYsdeTrEtevu2jJ_8aPinH/view?usp=s haring To generate my contour lines, I use mainly hgt2osm, with hgt files from Sonny. Hgt files in the example : N46W002.zip N46W001.zip N46E000.zip N45W002.zip N45W001.zip N45E000.zip Command line hgt2osm -g HGT-AFAIRE --MinorDistance=10 Hgt2Osm, 13.11.2017, FSofT 64 Bit-OS: ja Programmodus 64 Bit: ja MinorDistance: 10 MediumFactor: 5 MajorFactor: 5 HGT-Verzeichnis: HGT-AFAIRE Mergefile: OutputOverwrite: False Höhenkorrektur: -0.5 MinVerticePoints: 3 MinBoundingbox: 0.0005 Douglas-Peucker: 0.04 1. OSM-ID: -1 mit OSMBound: False mit OSMBounds: True mit OSMTimestamp: True mit OSMVersion: 1 mit OSMVisible: False max. Punktanzahl je Weg: 500 mit 'contour_ext'-Tag: True At first sight, it seems that all these artefacts begin just near a vertical line situated at W0° 00' 00" / E0° 00' 00" Any ideas to helps me to solve the problem? Many thanks Regards Gerard Cattiaux
Hi Gerard, I don't know the program hgt2osm, I would suggest to contact the author or try one of the alternatives like srtm2osm or Phyghtmap: https://wiki.openstreetmap.org/wiki/Srtm2Osm https://wiki.openstreetmap.org/wiki/Phyghtmap Or do you think that the generated OSM data is okay and it is mkgmap that fails? Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Gerard CATTIAUX <gerard-mkgmap@gmx.com> Gesendet: Donnerstag, 10. März 2022 14:15 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: [mkgmap-dev] Contour lines with "Artefacts" near a vertical line situated at W0° 00' 00" Hello, After many hours of time to get a correct knowledge of the most important tools needed to produce Garmin map, like mkmap, Splitter.. and plenty of hours to develop my own Styles files for mkgmap, I am now able to produce local maps mainly for Fenix 6x or Garmin 66, specifically for Trail Running. That help me also to have a mean to verify immediately all my contributions to OSM database. To have the best results for my personal maps, I use altitude data from Sonny. https://data.europa.eu/data/datasets/dtm-europe?locale=en For flat part of the country, I generally generate contour lines with a 5m space, in lieu of a 10m or 20m space between contours lines. That choice seems for me a very good choice for as an example "Ile de France" (Extended Region around Paris), where max altitude are between 150 to 200m. I recently generate contourlines near La Rochelle in France for a local zone called "Poitou-Charentes", http://download.geofabrik.de/europe/france/poitou-charentes.html but unfortunately, I have artefacts, that I don't have for example in many other regions of France. These artefacts are also visible for 5m, 10m and 20m space between contours lines. These "artefacts" are described in the pdf files given at this link: https://drive.google.com/file/d/1uiA51R4Kd_WYsdeTrEtevu2jJ_8aPinH/view?usp=s... To generate my contour lines, I use mainly hgt2osm, with hgt files from Sonny. Hgt files in the example : N46W002.zip N46W001.zip N46E000.zip N45W002.zip N45W001.zip N45E000.zip Command line hgt2osm -g HGT-AFAIRE --MinorDistance=10 Hgt2Osm, 13.11.2017, FSofT 64 Bit-OS: ja Programmodus 64 Bit: ja MinorDistance: 10 MediumFactor: 5 MajorFactor: 5 HGT-Verzeichnis: HGT-AFAIRE Mergefile: OutputOverwrite: False Höhenkorrektur: -0.5 MinVerticePoints: 3 MinBoundingbox: 0.0005 Douglas-Peucker: 0.04 1. OSM-ID: -1 mit OSMBound: False mit OSMBounds: True mit OSMTimestamp: True mit OSMVersion: 1 mit OSMVisible: False max. Punktanzahl je Weg: 500 mit 'contour_ext'-Tag: True At first sight, it seems that all these artefacts begin just near a vertical line situated at W0° 00' 00" / E0° 00' 00" Any ideas to helps me to solve the problem? Many thanks Regards Gerard Cattiaux
Hi Gerard, you can check the elevation contour lines by opening the file generated by your tool in e.g. JOSM (my take some time when the file is large). Strange distortions are expected at the borders of the whole set of input files, but not where input files are adjacent to each other. Your description seems to hint to a bug when crossing the 0°-meridian. I do not know how srtm2osm reacts there, it might be worth to try it. Kind regards, Bernhard Am 10.03.2022 um 14:15 schrieb Gerard CATTIAUX:
Hello,
After many hours of time to get a correct knowledge of the most important tools needed to produce Garmin map, like mkmap, Splitter.. and plenty of hours to develop my own Styles files for mkgmap, I am now able to produce local maps mainly for Fenix 6x or Garmin 66, specifically for Trail Running.
That help me also to have a mean to verify immediately all my contributions to OSM database.
To have the best results for my personal maps, I use altitude data from Sonny.
https://data.europa.eu/data/datasets/dtm-europe?locale=en
For flat part of the country, I generally generate contour lines with a 5m space, in lieu of a 10m or 20m space between contours lines.
That choice seems for me a very good choice for as an example "Ile de France" (Extended Region around Paris), where max altitude are between 150 to 200m.
I recently generate contourlines near La Rochelle in France for a local zone called "Poitou-Charentes",
http://download.geofabrik.de/europe/france/poitou-charentes.html
but unfortunately, I have artefacts, that I don't have for example in many other regions of France.
These artefacts are also visible for 5m, 10m and 20m space between contours lines.
These "artefacts" are described in the pdf files given at this link:
https://drive.google.com/file/d/1uiA51R4Kd_WYsdeTrEtevu2jJ_8aPinH/view?usp=s...
To generate my contour lines, I use mainly hgt2osm, with hgt files from Sonny.
Hgt files in the example :
N46W002.zip
N46W001.zip
N46E000.zip
N45W002.zip
N45W001.zip
N45E000.zip
Command line
hgt2osm -g HGT-AFAIRE --MinorDistance=10
Hgt2Osm, 13.11.2017, FSofT
64 Bit-OS: ja
Programmodus 64 Bit: ja
MinorDistance: 10
MediumFactor: 5
MajorFactor: 5
HGT-Verzeichnis: HGT-AFAIRE
Mergefile:
OutputOverwrite: False
Höhenkorrektur: -0.5
MinVerticePoints: 3
MinBoundingbox: 0.0005
Douglas-Peucker: 0.04
1. OSM-ID: -1
mit OSMBound: False
mit OSMBounds: True
mit OSMTimestamp: True
mit OSMVersion: 1
mit OSMVisible: False
max. Punktanzahl je Weg: 500
mit 'contour_ext'-Tag: True
At first sight, it seems that all these artefacts begin just near a vertical line situated at W0° 00' 00" / E0° 00' 00"
Any ideas to helps me to solve the problem?
Many thanks
Regards
Gerard Cattiaux
participants (3)
-
Bernhard Hiller -
Gerard CATTIAUX -
Gerd Petermann