BLIPtoMAP program description

This is a simple utility that converts Dr Jack's BLIPMAPS (see for BLIP and RASP soaring forecasts) into GPS_LOG map files. This is a simple utility that does no shape smoothing of derived isolines so expext maps to have "rectangular appearance". In order to obtain data go to Dr Jack's site and download them just as if you were accessing visual data. Change the png extension to data or if data is not available. In the latter case you need to unzip the downloaded file. So for example becomes After you receive the data file save it somewhere where you can access it with BLIPtoMAP Click on "Get File" button and choose the file. Program will convert it and save with map extension, so will be converted to Program DOES NOT WARN if it overwrites existing file.

Program looks at the range of data values in original file (information contained in file header) and divides it into eight (may be changed in the future) ranges. Each range is assigned a fill color that can be selected by clicking on a colored "Level x" button and choosing a color. Conversion is done by finding level isolines converting them to polygons understood by GPS_LOG program and ordering them so that smaller included shapes are on top of the larger ones.

Layer program options:

1) Topography - generated shapes are assigned to GPS_LOG topography layer which is drawn before anything else

2) Overlay - generated shapes are assigned to overlay layer which is drawn after topography and alarm zones layers. Overlay layer display can be toggled. This option defaults to None for GPS_LOG versions lower than

3) None - shapes are included in the general object layer. They are drawn in FIFO order to gether with others.

Transparency options (requires GPS_LOG version and higher):

1) Translucent - Generated shapes are drawn with solid fill in semitranslucent manner on top of previously displayed shapes. This means that color appearance is not guaranteed for these shapes as they will depend on what is below. this is particularly important for smaller included shapes which overlay shapes belonging to lower levels. If you use this option, experiment with color till you are happy with results. In general it is better to work with basically the same color and differentiate level by color saturation, or start with two component color (like yellow) and progress to single color (like red).

2) Hatched - same as translucent, but instead of solid color hatched pattern (one of six) is generated with type of hatch and color being determined by level.

3) Opaque - solid not transparent color.

Isoline level controls:

Click on a button with a value to change it. Level values have to increase monotonically
Click on Reset to get default isoline levels based on information in file
Click on Recall to recall values used last time you clicked "Make Map" They may or may not make sense

When "Get File" is clicked and file selected, program automatically creates map file based on default (Reset) isoline values

Download BLIPtoMAP      Current version:,  20 June 2007

 To install download zipped archive and extract the executable to the same folder as GPS_LOG Win32.exe Archive includes an example of data file and a binary GPS_LOG map which can be used in conjunction with map generated by BLIPtoMAP.


Other Soaring Pilot Software programs:

 Freeware Flight Display,    GPS_LOG ESRI shape, E00 and Digital Elevation Data files to GPS_LOG WinCE map converters, and  Magellan GPS to IGC track format converter, Geoid

Commercial programs       

For other things see the home page