DCS GCI
Scope

What it is

The DCS GCI Scope is a custom radar interface for the GCI (Ground Controlled Intercept) operators of the 104th White Wyverns. It provides a realistic visualisation of air contacts during DCS World missions, with two distinct operating modes depending on the scenario.

Why it was created

LotAtC is the standard tool used in DCS for GCI operations and air traffic control. It works well as a coordination system, but its interface doesn’t replicate the aesthetics or the operating procedures of real military radar systems.

For the 104th White Wyverns, procedural realism is a core part of the activity. A GCI operator working on a scope faithful to the real systems improves immersion, makes communications more precise and raises the overall quality of the missions. The GCI Scope was born from this need, integrating LotAtC as a higher visual layer.

Cold War mode

Amber-phosphor CRT aesthetics on a dark reddish background, inspired by the naval tactical displays of the ’70s-’80s (AN/SPA-25, UYA-4) and the real C2 systems of the era.

NATO symbols:

• Chevron — Aircraft (oriented in the heading direction)
• Circle with a line — Helicopters
• Square — Ground units
• Diamond — Ships

Plot-to-track: new contacts appear as raw plots (+) for the first 2-3 sweep passes, then are automatically correlated into full NATO symbols with an assigned Link-1 number. It simulates the Video Extractor process of real C2 radar systems.

IFF system: contacts of your own coalition show two bracket arcs around the symbol. Contacts with no IFF response are classed as UNKNOWN. The coalition is set from the controls panel (BLUE/RED).

Jamming: a contact under ECM produces a radial noise sector on the scope (strobe). If it’s friendly, IFF identifies it with the brackets; if it’s unknown it turns orange UNKNOWN and blends into the background noise.

CRT effects: scanlines, vignette, amber glow, dynamic clutter simulating real environmental interference, phosphor decay between sweep passes.

Modern mode

A modern tactical display with full information for contemporary operations.

• Coloured tracks: BLU, RED, Neutral/Unknown
• A data block for each track: callsign, Flight Level, speed, heading
• Speed leader lines (30-second position prediction)
• Track history with dots of previous positions
• Orange circle on human pilots
• Click a track for the BRAA panel (Bearing, Range, Altitude, Aspect)
• Right-click on the scope to place the bullseye point

Donor and operator view

The controls panel separates two concepts that used to coincide: where the radar is and where the operator is looking.

The reference radar unit (DONOR) is a dropdown of your own coalition’s units that have an active ground radar (SAM, EWR). With “Real coverage” the scope shows only what that radar actually sees, range, horizon and terrain included. Selecting one physically centres the scope there and the radar beam emanates from its position. The operator view is instead an independent coordinate field: the “camera” can move elsewhere (including with the C hotkey, which recentres the view on the cursor) while the donor stays a fixed reference position.

Link-1 watchlist and AEGIS roles

The Link-1 table starts empty: the operator builds the watchlist by hand. You click a track on the scope (a dashed white selection ring appears), press +, and the track receives a Track Number. In Cold War this initiation is a deliberate choice, faithful to the doctrine of the era when there was no modern IFF datalink and classification was manual.

Selected tracks get an AEGIS/Link-11 role with the 1-7 hotkeys (or by clicking the row in the Link-11 legend): Friend, Interceptor, Kilo, Faker, X-Ray, Pending, Unknown. Roles are persisted server-side, so every GCI station sees the same symbols, and they recycle on mission_start. Watchlisted tracks use a datalink-style tracker with fast refresh (2.5s) and a predict, gate and quality chain, while raw contacts follow the sweep’s pace.

Zoom window

The Z hotkey opens a floating magnifying window (amber palette in Cold War, blue in Modern). It behaves like a magnifying lens over the scope area underneath, with 1.5× / 2× / 3× / 4× factors, a header to drag and a resize handle. It’s click-through, so clicks pass through the window to reach the scope below, and it remembers position, factor and size between sessions. Useful to read two contacts near the scope edge without moving the radar centre.

Ground aircraft and missiles

The scope tells in-flight contacts from grounded ones. In Cold War the MTI threshold of the VIDEO knob also gates the symbology: a parked jet generates no plots and isn’t correlated to Link-1, exactly like the real Video Extractor working on the MTI-filtered video. Only the IFF diamond stays, because the transponder answers the SIF interrogation even when stationary, and the contact reappears as soon as ground speed crosses the threshold (the take-off roll reveal). In Modern a ground contact (below 30 kt) is dimmed to 45% and drops its data block, to keep the picture clean over the airfields, and returns to full on take-off.

In-flight missiles arrive as dedicated ephemeral contacts: in Modern they show as a dart (blue for BLU, orange for RED) with an engine trail and a long velocity leader that, at Mach 3, makes the intercept trajectory readable. In Cold War they’re discarded, since the ground radars of the era didn’t track targets that fast. They’re never selectable in any mode.

Bullseye

A shared reference point for standardised radio calls (“BULL 283/54” = bearing 283°, 54 NM from the bullseye). It’s set from the URL in the briefing link, manually from the Track Info panel, or by right-clicking on the scope in Modern mode.

Coastline overlay

The scope automatically shows the coastline of the current theatre, derived from the data transmitted by the DCS script. In Cold War it appears as a faint dashed green line (acetate style, like real ground radars of the era); in Modern as a solid line with a semi-transparent fill. Supported theatres: Caucasus, Persian Gulf, Syria, Nevada, Sinai, Falklands, Kola.

URL parameters

The scope is configurable via URL, designed to be attached to the mission briefing with everything preset.

?mode=coldwar&side=blue&range=150&lock=1&link=WW&bull=42.80,41.20

With lock=1 the mode toggle is hidden and the operator can’t change the configuration during operations.

Interactive demo

The scope is publicly accessible with a preloaded sample mission that runs continuously. No need to launch DCS, no need for a Lua script: open the link and watch the air contacts move on the scope as during a real operation.

From v3.2 the demo is no longer a simple drift of contacts but a tactical scenario over Syria with separated factions (BLUE south, RED north, FLOT as a buffer), CAP orbits and patrols. Every eight minutes a scripted engagement kicks off: a Fencer crosses the FLOT, the Vipers intercept and launch FOX-3, the MiG-29s react with R-27ER, the Patriot fires PAC-2, then abort and return with rearm. All on loop, so there’s always something interesting to follow on the scope.

What you can do in the demo:

• Switch between Cold War and Modern from the controls panel and see how symbols, palette and behaviour change
• Change the coalition (BLUE / RED) to observe how the contacts’ IFF classification changes
• Click a track in Modern mode for the BRAA panel
• Right-click on the scope to place the bullseye in a custom position
• Change the scan range and watch the contacts reposition
• Attach the URL parameters (?mode=coldwar&side=blue&range=150...) to test briefing configurations

The demo is meant both for the 104th’s GCI operators who want to get familiar with the controls before operations, and for anyone who wants to understand how a realistic tactical radar scope works.

How it works technically

Unlike Live View, which uses mission_live_export.lua (god mode), the GCI Scope can use gci_mission_script.lua, a script that loads directly into the DCS mission via a trigger. This script only sees the targets detected by the radar sensors of the configured coalition (AWACS, EWR, SAM). If a target flies low and no radar acquires it, it doesn’t appear on the scope: 100% realistic detection.

The tool is publicly accessible at gcidemo.alessandrosimonitto.it/gci, ready to be attached directly to the mission briefing with all parameters preset via URL.

Hosting it on your own server

The repository ships a step-by-step install guide (INSTALL_DCS_SERVER.md) for running the scope on your own group’s server: Windows install, hooking the export script into Export.lua, LAN testing on the same machine as DCS and, if you need access from outside, a Cloudflare Tunnel with the app switched to “behind proxy” mode (secure session cookies, HSTS, protected admin area).

MissionScripting.lua is not touched: the mission script opens no sockets, it queues the packets and a hook in the GUI environment collects them and sends them over UDP, the same road SRS and Tacview take. Earlier versions asked to desanitise the sandbox, and the guide also explains how to restore a file that was already modified. The installer (install.bat) copies mission script and hook without overwriting a file already changed by hand.