The web interface has three use cases: Calibration, Marking and Verification.


Purpose is to intitialiize the beacons and station positions. Beacons operate on radio multilateration. Stations are beacons that add additional precision using laser distance metering. In the use case view, beacons are represented as circles and station as squares.In a fresh topology, you start calibrating the radio beacons, as they include the stations as well.

This guide assumes the hardware is installed and connected to the server, if this is not done the use case pages will show empty.

The calibration page has two panes: at the left there are controls for the setting and at the right the graphical representation of the topology.

Beacon Calibration

Make sure you select the ""beacons" tab, showing the calibration matrix. Each cell shows the distance between the beacon in the row and the one in the column. If it is not determined it shows --. By pressing the "calibrate" button you ask the hardware to determine these distances. Pressing "optimize" determines the x,y,z positions of each beacon so that the matrix is optimally fitted.

However the orientation of the entire topology is undetermined since there is no reference. To help you understand the topology, the "hull" is shown. i. e . the shell composed of  the faces connecting the most outward beacons. In addition, the smallest containing box of the hull is also calculated. You can reveal these using the controls "roll", "yaw" and "pitch": roll rotates around the X axis (pointing towards the right), pitch rotates around the Y axis (pointing towards the bottom) and yaw rotates around the Z axis (perpendicular to the screen).

The faces are coloured according to their orientation, as if they were lit by a red light from the right and left,  green light from the top and bottom and blue light from the front and back.

The flip controls help you to turn the shape by 180 degrees in either direction.

The goal of the calibration is that you orientate the shape so that it is viewed from the top (i.e. X and Y axis). The "suggest" button aligns the shape so that the largest face on the enclosing box is indeed X and Y.

The yielded positions of the beacons are given in the "adjust" cells. They are always normalized so that one of the x, y or Z values are 0. It is possible that you want to enforce one of the beacon's positions and/or one of the dimensions. An example of the latter is that you know (by measurement) the heigths of the beacons. You can "enforce" values by entering them in the adjust table. clicing the "lock" tickmark (either beacon of dimension), and press "optimize" again.

Sometimes your topology is wider than the enclosing box, e.g. when you positioned all beacons in one plane. In that case, you can enforce a z-min and z-max value for the inclosing box.

Finally, the "tolerance" parameter tweaks the minimum distance between two valid solutions of the multilateration, which is important in small infrastructures (< 5 meters). For larger infrastructueres, 50-60  cm (0.5-0.6) is a good value.

Station Calibration

Stations need additional calibration since their initial orientation (pan and tilt) are unknown. During topology layout, stations should be mounted as much as possible horizontally, and facing towards the X axis. Evidently, this can only be achieved approximately; the purpose of the Station Calibration is to determine the pan and tilt adjustments. 

Make sure the "station" tab is ticked, and choose a calibration landmark in your topology with known coordinates, enter this  in X, Y, Z, and select "seek", all beacons will point to the marked coordinate. To adjust the pan and tilt for a particular beacon, you can apply the + and - controls for either azimuth (the horizontal  angle) or elevation (the vertical angle), until the beacon actually hits the landmark. You can set the "step" to adjust the stepsize. Clicking the "set" control will calibrate the pan and tilt of the beacon so that this landmark is correctly targeted.

Repeat this procedure for all stations.


A marking point is an (x,y,z) position to which the lasers can point to reveal their location

Please make sure to select the "Marking" tab. This one has two sub-tabs: a visualization ("show marking") and a defining ("edit position entries"). 

First let's enter some markers using the second tab. It shows an array of (x,y z) coordinates to mark. You can define one by filling in the row, or add or delete a row using the + and - buttons. To test out, entering the beacon's position is an excellent choice.

In the "Show Marking" tab, you have controls and visualization panes. The control again shows roll-pitch-yaw to determine the viepoint; e.g (75,-33,10) is a good choice for an isometric projection. You can open as many marking windows as you like, whith each it's own roll-pitch-yaw set, allowing you to view the scene from different angles.

Next, hit to one of the "mark" buttons in the "Listed Marking table". The stations will point to the selected coordinate (subject to correct calibration).



Not yet finished 

General flow: position of tag is tracked using radio localization, and shown in any of the "marking" pages. The determined position and quality parameters are shown in the table, The radio distances and qualities are shown above the topology schematic.

 If the "localize" button is pressed (on the site or on the device, the all stations consecutevely seek  the device (using the spiral seeking algorithm trying to hit the tag's photocell). Once all stations have hit the tag's photocells, laser-based triangulation is applied and reveals the precise tag's x,y,z position.