SLGI Trackers

The SLGI trackers are the fastest moving objects in Second Life. They are used for various tasks, usually related to SLGI vehicle maintenance.

## Behaviour

The SLGI trackers are designed to move with the highest speed possible. They usually move at an altitude of 1000 m and need less than a second to pass through a Sim. For example, to travel from Heterocera to Bay City and back, they need only one minute. They are set invisible and phantom, so that they don't interact with any object or avatar on the route. Because of their great speed, they are basically impossible to detect.

Trackers can sometimes be seen around SLGI bases when they are launched or when they return. They are green and spherical, made of a single prim. They are 0.1 m in size.

For safety reasons, they are designed to self-destruct if they get stuck for more than 10 seconds inside one sim. Their lifetime is 10 minutes, if they stay for longer they self-destruct, no matter if they have completed their mission or not. Also, because they are invisible and phantom, they don't interact with avatars or objects on the way. They only follow Protected Land and sometimes enter private-owned parcels (with permission). Usually they follow the same route as SLGI Trains or SLGI Fleet.

At their high altitude, they are not affected by no-script restrictions and are almost impossible to get stuck.

### Speed

The technology behind trackers makes them the fastest moving objects on the grid. Their speed is as follows:

* **2000 km/h** *inside the same sim*. However, this is not their purpose of existing.
* **1000 km/h** *without any scans or safety features*. However, at such speed, the simulators cannot handle them and they often end-up off-world.
* **500 km/h** *with basic safety route checkout*. However, at this speed, the simulators still might consider them as griefer objects.
* **200 km/h** *while doing surveys*. This is a safe speed for running up to 50 sims.
* **100 km/h** *for safety reasons*. At this speed, flight path is safe, all surveys are properly carried and the simulator has enough time to handle the trackers.

Because of all these reasons, speed has been set at 100 km/h, which is far less than the trackers have been designed for.

## Automatic Released Trackers

These trackers are released automatically to keep an eye on SLGI vehicles:

### Automatic Release

Trackers are automatically released when there is a problem with communication. SLGI Trains, SLGI Fleet and SLGI Taxis use an object-to-object HTTP communication which works only inside Second Life, without the use of an external server. They report to their bases information like position, if they are respecting schedule, if they have passengers or if there are lag problems along the route. If communication fails (for example during sim restart processes or during a griefer attack), trachers are automatically released to see what is going on. This also happens if a vehicle disappears during a failed sim crossing.

Automatically released trackers cannot send object-to-object HTTP messages. They are released to find a specified vehicle. On the way, they scan every sim looking for the specified vehicle, then return home and inform the base what they have found.

### Functions

* **Monitoring.** They report position of SLGI vehicles when object-to-object HTTP communication fails. They run along routes followed by SLGI vehicles and come back reporting their position with a delay of up to 5 minutes.
* **Detecting stranded vehicles.** These trackers are slower and fly at the same height with SLGI vehicles. They search for vehicles that got stuck during sim restart processes.

## SLGI Research Trackers

They are sometimes released for Geographic surveys by SLGI team.

### Manual Release

Trackers can manually be released for research purposes. This is done to check things like lag, population, percent of Abandoned Land vs Inhabited Land or to test sim crossing safety. Their main purpose is to check if there is a major concern for routes used by SLGI vehicles.

Manually released trackers use active object-to-object HTTP communication and they send real-time information to the SLGI bases They can also send instant messages to the avatar releasing them.

It was proposed to set trackers to check stability of roads, railways or waterways, available for anyone to check. At the moment, SLGI team is considering this, as a massive release of trackers can negatively affect sim performances and might be seen as a griefer attack.

### Functions

* **Emergency Shutdown.** In emergency situations, trackers can upload a self-destruct script to vehicles they encounter.
* **Testing routes.** They check stability of sim crossings along roads, rails or waterways. They also identify large scale griefer attacks.
* **Research.** Trackers can give information like percent of abandoned land, inhabited land, percent of land usage and number of avatars. For example, the Rezz Zone list was mostly done with the help of trackers.

## Resident Commanded Trackers

Since July 2023, the trackers have began to be made public, so that any resident can release them.

### Resident Commanded Release

Residents can click on the release button and chose one of the available routes.

**SLGI Base West** (Achemon <32,240,80>, Heterocera):

* Heterocera Route 1
* Heterocera Route 2
* Heterocera Route 3
* Heterocera Route 3.5
* Heterocera Route 3A
* Heterocera Route 3B
* Heterocera Route 4 West
* Heterocera Route 4 East
* Heterocera Route 5
* Heterocera Route 6
* Heterocera Atoll Coast Road
* Heterocera Great Bridge
* Heterocera Great Wall
* Heterocera Inner Atoll Roads
* Heterocera Inner Delta Roads
* Heterocera Mock Heather Road
* Heterocera Park Way
* Heterocera Robin Loop
* Heterocera Small North Roads
* Heterocera Small West Roads
* Heterocera SLRR East Line
* Heterocera SLRR Great Northern Line
* Heterocera SLRR Main Line (Central)
* Heterocera SLRR Main Line (East)
* Heterocera SLRR Main Line (West) + Branches
* Heterocera SLRR Maritime Line
* Heterocera SLRR Mountain Lines
* Heterocera SLRR North East Lines
* Sansara Bay City Railway + Trams
* Sansara GSLR
* Sansara ONSR
* Sansara Road Amida - Noyo & branches
* Sansara Road Amundsen & branches
* Sansara Road Bay City
* Sansara Road Claarksburg
* Sansara Road East Volcano
* Sansara Road Fables Sea Ring
* Sansara Road Far East
* Sansara Road Langdale
* Sansara Road Linden Highway
* Sansara Road Ski Runs
* Sansara Road Snow & branches
* Sansara Road West Volcano

**SLGI Base East** (Valarian <178,20,200>, Corsica)

* Corsica Circuit Road North
* Corsica Circuit Road South
* Corsica Circuit Shortcut 1
* Corsica Circuit Shortcut 2
* Corsica Circuit Shortcut 3
* Corsica Circuit Shortcut 4
* Corsica Route 10 North
* Corsica Route 10 Central
* Corsica Route 10 South
* Gaeta 5 Route 7 North
* Gaeta 5 Route 7 South
* Gaeta 5 Route 7A
* Gaeta 5 Route 7B
* Nautilus Route 12
* Nautilus Route 13
* Nautilus Route 14
* Nautilus N1 Expressway
* Nautilus City Roads
* Satori Route 8A North
* Satori Route 8A South
* Satori Route 8B
* Satori Route 8C
* Satori Route 8D
* Satori Route 8 North
* Satori Route 8 Central
* Satori Route 8 South
* Satori Route Old Wagon Road

**SLGI Base South** (Mooter <41,31,97>, Jeogeot)

* Jeogeot Route 9
* Jeogeot Route 9A
* Jeogeot Route 10
* Jeogeot Moleway
* Jeogeot North Spur Road
* Jeogeot Shortcut
* Jeogeot Wellington Road
* Jeogeot West Coast Road

**SLGI Base Sc** (Derby <9,88,27>, Sharp Continent)

* Sharp Bay City
* Sharp Central Roads
* Sharp Snowlands

**SLGI Base G1** (Nebelung <12,11,26>, Gaeta 1)

* Gaeta 1 Sandy Beach Trail
* Gaeta 1 Virgin Path
* Gaeta 1 Wedge Morgan Road

The system cannot be operational for Bellisseria and Premium Continents. Attempts to implement it in Zindra are not made since trackers could only cover a very limited area.

### Functions

* **Fast** - a tracker that travels along a route and reports back the time, speed and distance spent on the route.
* **Route** - a tracker that travels along a route and informs the avatars who has released it each time it crosses a sim border.
	+ *Lag detector* as one can estimate the lag level based on the time needed to cross a sim border
	+ *Sim crossing safety* as tracker will self-destruct if unable to cross a sim border.
* **Survey** - brings plenty of information about a route:
	+ *Basics* (distance, time, speed), which allows one to estimate lag level
	+ *Number of sims scanned*
	+ *Linden owned land* (in %, includes all Protected Land). It is better to live in an area with more protected land as it is less crowded.
	+ *Protected land with object restriction* (in %, if protected land does not allow object entry it means Automated Transportation is restricted in the area and also means that the area has a history of griefer attacks).
	+ *Abandoned land* (in %, the amount of Abandoned Land shows how interested are people about an area and how expensive and crowded land should be).
	+ *Resident owned land* (in %, the amount of Inhabited Land).
	+ *Resident owned land allowing access* (in %, here one can see how much Land With Restricted Access exists along the scanned route and this gives a good idea about how friendly people are in the area).
	+ *Avatars, population density* (highly varies over time of day and of week, but this still can give you a good idea about how active an area really is).
	+ *Land usage* (% of objects used from object allowance for the area, the more objects are the higher lag will be and the more active local community is).
	+ *High lag sims* (if you see anything listed here, it certainly is a griefer attack or a sim that is doing very bad).

## Other Systems

Apart from SLGI team, a similar technology employing fast-moving vehicles is used by the *Virtual Railway Consortium* to map trains running along the Second Life Railroad in Heterocera. They use a completely different technology, not related to SLGI Technology at all.

## Privacy Policy

Trackers don't record avatar names, avatar keys, parcel keys or names. Information does not go to any outside server, it is only stored inside SLGI bases. Even if a griefer attack is identified, information does not go outside Second Life and is not posed to the Linden officials. Trackers don't act as police dogs at all. They are only used for improving SLGI vehicle and for Geographic surveys.

## See Also

* SLGI Transportation Systems
* SLGI Trains
* SLGI Fleet
* SLGI Taxis
* SLGI Technology