Map Menu and Map Chooser

Map Menu:

Map Chooser

This will present you with a list of map files in your map directory. Click on map names to highlight them, this will cause them to be displayed when you click the OK button. You may select any number of maps. Clicking the OK button will display the selected maps. Cancel will abandon any changes. There are also shortcut buttons to select all of a certain type of map, or deselect all of the maps at once.

Enable/Configure Tigermap

Turning this option on causes Xastir to download the map from the US census bureau's online tiger mapping server. The dialog that comes up allows one to select which layers are displayed, as well as the brightness of the resulting map. This is only available if you have compiled with ImageMagick support.

Map Display Bookmarks

See the help topic Creating and using Jump Locations.

Locate Map Feature

This option brings up a search dialog where you can search through the labels in a GNIS file to find a specific location. It will center the map on the new location if it is found. The "GNIS File:" entry is saved between calls and between invocations of Xastir.

Disable All Maps

This option disables the loading of any maps. It is most useful when doing rapid zooming or panning, because it saves the need to load the maps on each redraw. Note that this option is not saved between sessions.

Coordinate Calc

This option opens a simple calculator that can convert between coordinate systems. This is useful for converting positions to the various formats used by different groups of people.

Enable Auto Maps

When enabled, any map found in the map directory (or any directory under it) will be displayed if it falls within the current display region. You can add any number of directory levels under the main map directory for your maps. Auto maps will go through them all and find what map (or part) should be displayed. All Maps will be merged into the viewing area. If you have a large quantity of maps, very detailed maps or a slower computer this can be quite slow. When this option is off, maps selected with the Map Chooser will be displayed.

Enable Map Grid

When enabled, this option will display a grid line every 10 degrees. As you zoom in it switches to a 1 degree spacing.

Enable Map Levels

When enabled, this option will try to filter out data when the zoom level shows large areas. This does not work will all maps but will work with the maps generated from Tiger Line maps at the aprs.rutgers.edu site. This does not decrease the loading times of the maps, rather it simply reduces screen clutter.

Enable Map Labels

This option toggles the display of map labels embedded in dosAPRS, winAPRS, GNIS, and ESRI shapefile format maps.

Enable Area Color Fills

This option controls the filling of vector maps. In certain cases, you may want to eliminate the fill to see maps below the top maps. Maps are loaded in alphabetical order by type, so renaming maps is a second but less elegant way to achieve the look you want.

Enable Weather Alert counties

This toggles the display of county warning area maps for severe weather. These maps can be obtained and installed according to the directions in the README.1ST file. They are displayed on screen when special weather alert messages are received, and expire after a time or can be remotely cancelled. The weather alert text can be seen under View|WX Alerts.

Background color

This option controls the color of the background behind the maps you have displayed. The background color is often entirely hidden by filled maps (see above).

Map Intensity

This controls the brightness of any graphics used as maps. This option only appears if you have compiled with GeoTIFF support.

Adjust Gamma Correction

This allows you to apply gamma connection to all loaded map graphics. Maps can be adjusted individually in their .geo files, see the section on .geos in "Map files and WX Counties". This option only appears if you've compiled with ImageMagick support, and does not apply to geoTIFF maps; see the above option.

Station Text Style

Controls which font and style to use for station text and others.

Mouse pointer menu

This option brings up the options menu normally available by right clicking.

One note on maps: Many of the currently available vector maps for the U.S. were created in NAD 1927 datum, while Xastir and other APRS(tm) programs use WGS 1984 datum. If zoomed in to a small area on the map the datum shift may be very noticeable. The USGS topo maps have their datum corrected by Xastir as they are displayed, so positions will generally be more accurate with those topo maps.

Details of locations to obtain many of the obove types of mapss are found in the file README.1ST

Map Locations

Hints on installing and organizing maps are found in README.1ST.

Maps in a pixel graphics format actually need a combination of two files, a data file with a graphic pixmap (.xpm) (or other format if you compiled with ImageMagick), and a calibration file (.geo). The .xpm file is the standard graphic format, available without additional libraries. If you want to save storage space you can use gzip to compress those files ("gzip map.xpm" will result in "map.xpm.gz"). Xastir detects this automatically during map loading. You can use XView/Gimp/ImageMagick and other programs to convert gif, jpg, and tif images into this format if you didn't compile with ImageMagick. If you get problems with maps in xpm format, please try to load and save the graphics with Gimp first, to convert all unknown colournames into the binary representation.

The geo file is a text data file that will tie the image to a location in the world. Here is an example of a geo file that will cover the entire world with the map world1.xpm:

FILENAME   world1.xpm
#          x          y        lon         lat
TIEPOINT   0          0        -180        90
TIEPOINT   639        319      180         -90
IMAGESIZE  640        320

.geo files can have many elements:

FILENAME filename

This specifies the filename of a map image to be loaded from the local disk.

URL http://website

This specifies the URL of a map image to be loaded from a web or ftp site. ImageMagick only.

TIEPOINT x-pixel y-pixel longitude latitude

Two tiepoints are required, and more than 2 will be ignored. these two lines are for connecting an x,y pixel position in the image to a lat and long position on the earth. The points should be as close as possible to the upper left corner and the lower right corner of the image for best accuracy.

IMAGESIZE pixels horizontally pixels vertically

This specifies the size of the image in pixels. If this is not set, the image will be loaded each map redraw, regardless if it is on screen or not.

DATUM datum

This feature is not implemented.

PROJECTION projection

This feature is only partially implemented, default is "LatLon", other possibility is "TM" to specify that the map is in Transverse Mercator projection.

# anything Any line with the first character of a '#' will be ignored.

ImageMagick specific image enhancements:

GAMMA

eg: GAMMA 1.2 or GAMMA 1.2,2.0,1.2
The first will change overall gamma for this image, the second will lighten green more than red or blue.

CONTRAST

eg: CONTRAST 0 or CONTRAST 1
Doesn't seem to do that much, other values make no difference.

NEGATE

eg: NEGATE 0 or NEGATE 1
0 will negate all colors, 1 just grayscale colors.

EQUALIZE

No argument.

NORMALIZE

No argument.

LEVEL black_point, mid_point, white_point

eg: LEVEL 0,1,65535
These values seem to be the defaults.

MODULATE brightness, saturation, hue

eg: MODULATE 90,150,100
These are percents, 100,100,100 is the default.

Special/nonstandard .geo files:

TERRASERVER

A file with just the word "TERRASERVER" will cause Xastir to retrieve a Terraserver satellite photo of the area on screen. Those services are not available for every place in the world. Note that using the Terraserver maps at any zoom above 256 will probably take a long time to load, won't show much detail, and probably won't display correctly. This is a limit of the Terraserver, not Xastir.

FINDU

CALL callsign

A file with the word "FINDU" and the second line "CALL " will retrieve historical data for the specified callsign, although using the Stations menu is the preferred method.

geoTIFF maps are a combination of two files as well: a .tif and a .fgd file. The .tif file is the actual map data. The .fgd file need only contain four lines like this (but may contain many other lines):

1.5.1.1   WEST BOUNDING COORDINATE:  -122.000000
1.5.1.2   EAST BOUNDING COORDINATE:  -120.000000
1.5.1.3   NORTH BOUNDING COORDINATE:  48.000000
1.5.1.4   SOUTH BOUNDING COORDINATE:  47.000000

Xastir uses those four lines in it's calculations to determine the corner points of a map, to see whether the map fits in the current viewport (so it can decide whether to skip it). If your map data are USGS topo maps, the .fgd file should be readily available to you. An added feature in Xastir is the ability to do datum translations from NAD 1927 to WGS 84 datum, which makes the USGS topo maps much more positionally accurate on the Xastir screen. If you don't have the .fgd file, the map will load fine, but the white borders won't be cropped and the size and rotation may be off a tad bit.

Xastir can now use USGS geoTIFF topo maps directly from the CD drive. Either manually mount the disk or use automounter to do it for you, and make sure you have a symlink created in your maps directory that points to where you mounted your CDROM drive. That's it!

Shapefile maps are also a combination of several files, a .shp file, a .dbf file, and a .shx file. You only need to select the .shp to load the map, but the other(s) must be present for the map to load correctly.

GNIS (Geographic Names Information System) data is a collection of names of locations, or geographic features. These labels behave like map labels in Dos/WinAPRS maps. As you zoom in, more labels will appear, assuming you've selected the GNIS file as a map and have enabled Map Labels in the Maps menu.

WX County Maps

As NWS messages are received, different areas will get tinted to designate areas of concern. They are color-coded to specify different types of alerts. The basic colors are: Cyan for advisory, yellow for watch, red for warning, orange for cancelled alert, royal blue for tests, and green for undetermined alert levels. With recent versions of Xastir the colors may be different because the areas are tinted instead of color-filled, and the tinting depends on the colors underneath. The tinting is done with a pixmap stipple that displays the type of alert, if it is able to be determined. These change was made so that the underlying maps may still be seen underneath the weather alert areas, and so the alert type may be more easily determined, as sometimes matching the alerts on screen and in the weather alerts dialog is difficult. The display of weather alerts may be turned on/off via the Map menu.