User Guide – Falcon 4.0

## Introduction

Tacview offers an interesting alternative to the native Falcon 4.0 ACMI viewer. With Tacview you can enjoy smooth and instantaneous time control, modern ergonomics and embrace in a single glance the whole battlefield, while keeping an eye on every little detail which matters.

Tacview natively supports Falcon 4.0 `.VHS` and DTC `.INI` files. Since Falcon 4.0 can natively record flight data, there is no need to setup or install an export script. However, for best replay experience, it is suggested to increase the maximum `.VHS` file size using the appropriate option in Falcon 4.0 as described below.

Tacview also natively supports Falcon 4.0 terrains and databases. The most popular battlefields are already included, and if your favorite terrain is not yet supported, you can import it in Tacview in no time!

## How to use Tacview with Falcon 4.0?

### How to record a flight in Falcon 4.0?

All you need to do is to press the F key – while flying – to start data recording. After the flight, one or several .VHS files will be stored in the `\Falcon BMS 4.33 U1\User\Acmi\` or `\Falcon AF\acmibin\` folders.

No indication is displayed in Falcon confirming that recording is active, so if you want to be sure you are recording the best way is to check the above-mentioned folders to see if a file is being created.

### How can I specify a theater when I open a `.VHS` file in Tacview?

When you open a `.VHS` file in Tacview, it is important to not forget to specify which theater the flight is taking place in. To do so, simply use the appropriate list box in the open-file dialog box. Because it is impossible to auto detect the theater of a `.VHS` file, each time you open a new file, Tacview will use the last theater specified.

### How to import a DTC file in Tacview?

When you open a `.VHS` file, Tacview automatically tries to open a corresponding DTC `.INI` file with the same name. You can also load any DTC file afterward by using the file-merge feature or by drag-and-dropping any DTC file over the 3D view. You can load and visualize as many DTC files as you want within the same mission.

### Falcon 4.0 creates many little DTC.VHS files for each flight. Is it possible to open and merge all of them at once in Tacview?

Yes, you can merge files in Tacview. However, until Tacview 2.0 is released, this feature will remain experimental and will mainly work for .csv files. That said, the solution is simpler than expected: In Falcon 4.0, go to `Setup` -> `Simulation` and set `ACMI File Size` to a large value like `500 MB`. This will prevent Falcon 4.0 from creating a new file every single minute of a heavy loaded mission.

## How to display the proper terrain?

### The terrain displayed in Tacview is not the right one! How can I fix that?

First, you have to make sure that you have selected the proper theater when you opened the `.VHS` file (see the dedicated question above). Then, you have to make sure that Tacview is not trying to display the terrain from another flight simulation or real-life.

Because it is not easy to auto-detect which version of Falcon 4.0 has been used to create a `.VHS` file, by default, Tacview displays Falcon 4.0 BMS terrain.

### How can I import my own Falcon 4.0 terrain in Tacview?

Tacview already includes the most popular Falcon 4.0 theaters. You can easily add your own terrain by modifying the file `C:\Program Files (x86)\Tacview\Data\Xml\Data-Falcon4Theaters.xml`. Detailed instructions are provided in this very file. Tacview natively supports Falcon 4.0 terrain format, so you can directly declare your original add-on data like below:

```
<Theater ID="Balkans">
	<Terrain>C:\Games\Falcon BMS 4.33 U1\Data\Add-On Balkans\Terrdata\terrain\</Terrain>
	<Database>C:\Games\Falcon BMS 4.33 U1\Data\Add-On Balkans\Terrdata\objects\</Database>
	<LOD>2</LOD>
	<West>11</West>
	<East>21</East>
	<South>36.625</South>
	<North>46.64</North>
	<Visible>1</Visible>
	<TimeZone>+1</TimeZone>
</Theater>

```

### My favorite airports are not displayed, how can I add them as well as additional navigational aids?

Most of South Korean and Israel areas airports have been added to Tacview. However, because this is a long process, some airports may still be missing from your favorite region. You can add easily your own airports by following the instructions provided in the documentation about Static Objects.

## General Questions

### Why some ground units, aircrafts or weapons are not properly displayed in Tacview?

Each Falcon 4.0 theater require its own distinct object database. Make sure to specify the proper theater when opening a .VHS file in Tacview (see **How can I specify a theater when I open a .VHS file in Tacview?** further up on this page). It is possible that your favorite theater is not yet supported by Tacview or has evolved over the time. If this is the case, it is easy to declare a theater so Tacview can automatically import the latest database for it (see **How can I import my own Falcon 4.0 terrain in Tacview?** further up on this page).

### Some flight recordings are huge! How can I save some disk space?

Some flight recordings can be huge because they are written in uncompressed text format. You can load them and save them from Tacview. They will be compressed in a much more compact binary format which is going to save a lot of storage space of bandwidth. You can also use the command line to compress files in batch (see the help menu in Tacview for more details about command line arguments).

### Which versions of Falcon 4.0 are supported by Tacview?

Tacview can read data from almost any version of Falcon 4.0. However, only the following versions are officially supported:

* Falcon BMS 4.34

### How to convert Falcon 4.0 coordinates in Tacview longitude/latitude?

Use the following formula with the proper parameters:

```
longitude = west  + x * (east  - west ) / (width  * 819.995);
latitude  = south + y * (north - south) / (height * 819.995);

// Where:
//   x,y are falcon coordinates
//   north, south, east, and west are the terrain boundaries (in degrees)
//   width and height are the terrain size in samples (4096 in most case)

// This gives us the following for the Korean theater declared in
// C:\Program Files (x86)\Tacview\Data\Xml\Data-Falcon4Theaters.xml

longitude =   123 + x * (132.26 -   123) / (4096 * 819.995) =   123 + x * 0.00000275701
latitude  = 33.79 + y * (    43 - 33.79) / (4096 * 819.995) = 33.79 + y * 0.00000274213

```