In recent months, I have been experimenting with various GPS solutions to supplement my onboard GNS 430, which is a good piece of kit for IFR, but not always so for VFR. One of the hardware platforms I tested was a
Chinese navigator with SiRF Atlas IV chipset running Windows CE. The device itself is very decent and more than worth its price of $70.
Of the sofware I tried, SkyDemon was an undeniable leader in terms of functionality, but it was just too slow, so I settled on the old trusty OziExplorer, and will probably be using it in my routine flying.
An electronic ICAO chart for Germany (plus adjoining areas) for this year was pulled off the web. It does cover my base airfield in Czech Republic, but not much further eastward, so I embarked on making my own ICAO chart of Czech Republic.
Air Navigation Service of the Czech Republic does offer a current
airspace chart in PDF format for free download, but it's only an airspace layer in Lambert projection, without the underlying topo base, and the file is not georeferenced. I opened it in Global Mapper and calibrated it by hand (took me 10 minutes), then started looking for a suitable base map. As it turned out, there are quite a few maps available for free download. My favourite ones are a 1:500000 Land Cadastre topographic map available through WMS from
http://geoportal.gov.cz/ArcGIS/servi...rver/WMSServer and the World Topo Map (a link is included in Global Mapper). The former is more informative (and ostensibly more accurate), the latter is sharper and better coloured. Here is how to make an ICAO chart out of the above:
1. In Global Mapper, load the base map as the bottom layer and the airspace on top of it.
2. To make the airspace borders clearly visible, use the control centre in Global Mapper to lighten the base map layer to your own taste (I used -100 for colour intensity).
3. Set the blending mode of the airspace layer to "darken" (also in the control centre). Play with other display parameters if you want.
4. Once satisfied with the look of the overall combination, export it into GeoTIFF.
5. Import the GeoTIFF into the desktop version of OziExplorer, creating a .map file.
7. Use Img2ozi utility from OziExplorer to convert the GeoTIFF into .ozfx3.
8. Load the .map/.ozfx3 set into your navigator and check if you like how it looks.
9. If an additional colour correction is necessary, you can just edit the GeoTIFF in an image editor. The calibration is already stored in the .map file and won't be lost. Then go back to step 7.
10. If the default scale on the navigator screen is inconvenient, go back to step 7 and change the initial resize factor.
As it turns out, EU has recently mandated all member states to create public geoportals, and this is where one can hope to get standard base topo maps for free; if none is available, one can always use World Topo Map. Now, the question is about the airspace layer. So far, I am only aware of the Czech one in PDF format. There are digital airspace descriptions avialable for many countries, but I am not sure whether they can be easily transformed into nicely looking graphic images. Your input on that will be greatly appreciated.