Introducing the FalconView Map Data Manager

I have placed a set of example map data used in this example in the downloads section http://www.falconview.org/trac/FalconView/downloads/12 here.

One of the primary features of FalconView is its Map Management tools which have been designed to allow users to catalog and use very large sets of map data. Data is set up using the Map Data Manager which is available under "Tools->Map Data Manager".

Working with Data Paths

FalconView was designed with the idea that users would store map data either in a directory on a local hard drive or in a directory on a shared network drive. Each Directory and its underlying sub-directories is called a "Path". When you first install FalconView it puts a few Map Files on your local hard drive. The data is in the "Shared Documents" directory and on a Windows XP machine defaults to "c:\documents and settings\all users\documents\pfps\data". There is also a default path to your CD/DVD drive. You can add a new path to the Map Data manager to point to another set of data. A common practice is to store a large amount of data on a shared map path for instance
WorkgroupServer\MapData. Once you have more than one active path, you will need to decide which path will be your "Target Path." Your target path needs to be someplace that you have write access. It is the place that new data is copied to or deleted from when you use the other features of the Map Data Manager.

Now lets create a new directory on your machine and get some data in it:

1. Windows explorer or a command prompt to create a new directory on your hard drive: c:\Maps
2. Now we want to put a couple simple map files in that directory. For performance reasons, FalconView needs to assume some default director structure on the target path. Depending on the type of map data that you want to read, the directory structure can get pretty complicated but some of it can be done trivally:
   1. GeoTIFF data can be either in the top directory or in a directory called "GeoTIFF" so in our example, if you had a GeoTIFF File called choca.tif you could either put it in c:\maps\choca.tif or c:\maps\GeoTIFF\choca.tif. (upper/lower case is not important)
   2. MrSID data must go in either the top directory or the "MrSID directory. So a Sid file called "n-16-25_30_loc.sid" would go in either c:\maps\n-16-25_30_loc.sid or in c:\maps\mrsid\n-16-25_30_loc.sid.
   3. DTED data (Digital Terrain Elevation Data) is more complicated. The data needs to go two levels down and be broken up by the longitude. DTED comes as 1deg x 1deg tiles and are named after their Latitude so there are many DTED files with the same name! A file covering W85 N33 to W84 N32 would be named N33.dt1 and would go in the DTED\W85 sub directory while one covering W86 N33 to W85 N32 would also be named N33.dt1 but would go in the DTED\W86 sub-directory. In this example c:\maps\DTED\W85\n33.dt1 and c:\maps\DTED\W86\n33.dt1
   4. RPF data (CADRG or CIB) data produced by [www.nga.mil NGA] is even more complicated but needs to be in a subdirectory off the RPF directory. They normally are stored in the same directory structure in which NGA distributes the data on CD for instance CADRG and CIB formats are broken down by product and then by RPF Zone numbers. The NGA version of NOAA sectionals use the product code "LFC" and most are in zone 2 which is a band between 32 deg N latitude and 48 deg n Latitude. So the files would be in RPF\CLFC\2\000hh083.lf2. See the topic of MapTypes for more details on RPF directory structures.

It is important to realize the map data is generally in a subdirectory off the top level map data path. In the case of DTED if you added a path to c:\maps\dted it would not find any DTED. You need to add the path to c:\maps.

To summarize:

x:\Maps\GeoTIFF
   file1.tif
   file2.tif
   ...
x:\Maps\MrSID
   file1.sid
   file2.sid
   file3.sid
   ...

x:\Maps\DTED\w085
  n33.dt1
x:\Maps\DTED\w086
  n33.dt1

x:\Maps\RPF\clfc\1\
   006f5043.lf1
   006f6043.lf1
   006f7043.lf1
   ...
x:\Maps\RPF\clfc\2\
   000hh083.lf2
   000hj0c3.lf2
   ...

Most users never have to look at the directory structure of most map types because they copy the data from CD using the map data manager. In this case you insert the CD and let FalconView find and catalog the data on CD and they you use the single or multiple tabs to select a region to copy and then pressing the copy button automatically copies the data into the desired directory structure.

3. Now that you have one or more maps in directories off the c:\maps directory. We need to add a path in the map data manager. Choose the Path Tab from te Map Data Manager Window and then click "Add Path...". Browse to c:\maps. FalconView should display a message saying "Map Data Found". Click Add and then OK. You should see FalconView pop up a dialog which says "Generating Coverage". Depending on the amount of map data it may take a few seconds. (If you have Terabytes of data it may take an hour or more).

Once you are done, FalconView knows about all the data on that path. If, for some reason, you need to manually copy more data (using windows explorer) into an existing map data path, you will need to perform a "data check" by selecting the path in the map data manager and pressing the "Data Check" button. This is the way to tell FalconView that the data has changed and it needs to re-scan the directories.

Viewing Data Coverage

Now that you cataloged the data, you probably want to verify that it is the right data for your area of interest. We do this using either the "single" or "multiple" page of the Map Data Manager. The Single page has a dropdown listing all of the map types that are on your system. Out of the box, it will probably just list "TIROS World", "TIROS 16km", and "TIROS 8km". If you added the chocta.tiff, n-16-25_30_loc.sid and d33.dt1 files from the sample data you will also see MrSID 30m and GeoTIFF 1:30K and DTED Level 1. If you select 30m MrSID, you will end up with a display somthing that looks close to this:

Note the red regions on the map in the Southeastern US. This is the extents of the data of that map scale on your system. In this example they are red meaning that the data is on a path that is not the "target path". You could click and drag the mouse over the region to select this data and then press "copy" to copy the data to the "target path" which would result in the little red region, becoming a little green green region.

Viewing the Map Data

At this point what we are probably most interested in, is viewing the map data so lets do that: The usual way for viewing an area of interest is to use the mouse scroll wheel to scale in and out through the data. Put the mouse over the center of the red region, and roll the mouse wheel forward, you will scale into the the map data or you could also position the mouse over the center of the region and press "Page up". You could also center the screen over the red region and then choose the map from the map menu. Map->Raster->MrSID->30M (color). Any of these will display something like:

If you select the 1:30K Geotiff, you will end up with something that looks close to this:

Note the little red regions on the map in the panhandle of Florida. You could use the mouse scroll wheel to scale in and out through the data if you are very careful and put the mouse exactly over the center of the red region. Unfortunately with this tiny piece of data, it is very hard to position the mouse precisely enough and if you "miss", FalconView will instead throw up a dialog saying: Data Not Available for the Selected Map. Use the Map Data Manager to view map data coverage. So what we need to do is scale in a little closer to the red region. You can switch to "Blank Map" which as the name implies is just a blank background. Then you can use the mouse to scale in to a closer scale (for instance 1:1M), so the region is a little bigger then use the map menu to switch to the 1:30K GeoTIFF. To do this select the Map Menu and then "Blank Map" or hit "F2" Then scale in using the mouse wheel or the Page-Up key while the mouse is close to the red region. Once the red region is covering the screen, use Map->Raster->GeoTIFF->1:30K to view the final chart.

Once you are viewing the data you want. Turn off the Map Data Manager so you no longer see the red cross hatching on your data.

DTED Data works essentially the same way but you must select it from the map menu since it is not a part of the "Raster Group". DTED is part of the "Elevation" Group so you need to center FalconView on the region of interest and choose Map->Elevation->DTED->3 Arc Sec (Level 1). In the following picture I have turned on the cross hairs to mark the center of the screen and centered the map over one of the two sample DTED Files. Choosing DTED 3 Arc Sec (Level 1) from the map menu will bring up the display of the DTED elevation.

Which looks like this (after playing with the Map Options to set the color banding):