Dienstag, 26. November 2013

Mappers Blog: The swiss quality management system for orienteering maps

Orienteering map production in Switzerland is supervised by the national orienteering federation. Here I give a short outline on the system regulated by the Kartenreglement des Schweizer Orientierungslauf Verbandes. I refere to the version which will be introduced in 2014.

  • Every mapping project gets screened by environmental issues
  • Every mapping project  gets checked about the accordance to the national version of the mapping norm (Symbolization, minimal gaps and sizes) and usually also field checked in regard to proper interpretation and generalization.
  • Additionally also proper drawing is an issue.
  • The maps quality promotion is executed by one of 13 consultants, each in charge for a certain region of Switzerland. These are all among the most experienced mappers we have and some of them are even closely linked to OCAD. Their role is consultative and as such they are in a mainly supporting and educating role. If the map is drawn for a member association of Swiss Orienteering, the Federation stands for the costs of the consultant.
  • A good cooperation between mapper and consultant usually results in the map being Q-labeled, represented by the Q behind the official map number.
  • From 2014 the label of the Federation will even include a rough information about the actual print quality of the map in hand. See figure above.
That way the Swiss Orienteering Federation secures the high quality of Swiss Orienteering mapping  the whole way from choice of terrain, to survey and drawing to print and as a side effect even introduced a flow of know-how from the experienced to the emerging mapper.

Donnerstag, 21. November 2013

Mappers Blog: How to get an object height basemap with Swiss Laser Data

Update: Read Jerker Bomans comment below. Swiss authorities provide two kind of processed terrain laser data. A DTM named DOM (Digitales Oberflächen Modell) and a DEM named SwissAlti3D (Digtales Höhenmodell), so basically two surfaces, one with (DTM) one without vegetation and buildings (DEM).

For mappers the object height is a useful perspective. With OCAD11 this perspective became accessible for mappers working with Swiss Data. For those who did not upgrade I describe a work around. Acutally it is possible to achieve the perspective with the freeware OL-Laser by modifying and fusion the two datasets.

Basically the Swiss Data consists in textfiles, with one points coordinates per line.
601999.58 196042.04 622.55
Now help OL Laser to interpret this coordinate with some additional information.
601999.58 196042.04 622.55 9 2 1 1
This by adding 4 values for intensity, number of returns, return number, classification behind the coordinates. In the example you have the signature for "surface": intensitiy 9, first return of two, unclassified. This signature you can add to the coordinates of the DOM.

For the DEM the signature looks like this
600005.00 196001.00 762.11 31 2 2 2
Here I choose an intensity  of 31 (just an arbitrary value). It is the second return of two (last return) and the point is classified as ground.

That was it: Modify the lines, fusion the two files and then proceed to OL-Laser.

 fig.1. Object height perspective of "Gurten Nordhang" produced with OL Laser.

By the way. The similar trick also makes the Swiss Data useable to the automatic map generator karttapullautin, only that the order in the signature to add is different. Here it is x,y,z,classification,returns,return nro, intensity. You therefore got to switch the places of classification and intensity.
600005.00 196001.00 762.112 2 2 31 (ground)
601999.58 196042.04 622.551 2 1 9 (surface)

fig.2. Not optimized karttapullautin map combined with vector data of openstreetmap of the same area.

Dienstag, 5. November 2013

Mappers Blog: Some simple measures to meet the ISOM2000 in regard of legibility

To meet the ISOM2000 in regard of legibility it is might be worth to add some extra symbols to your set. Used during the drawing, they easily can be removed for the final version.
  1. Minimal objects as point features (here: impassable cliff, passable rock face and marsh) to avoid  too small objects.
  2. Visual buffers for minimal gaps (pink: between buffered objects, green: between a buffered object an object of the same color
  3. Meter for minimal contour detail. 
  4. Meter for minimal knoll (if smaller, replace with small knoll or elongated knoll)