Available Aerosol Datasets Available Radiation Datasets Measurement Sites Data Visualization Daily Radiation Plots SURFRAD Daily Radiation Plots Baseline Near Real-time Aerosol Plots Near Real-time Radiation Plots Data Archives
Aerosol Primer Aerosol Terminology Radiation Primer Radiation Terminology "Red Sky in the Morning" BSRN 2018 Meeting BSRN 2016 Meeting
The INTRA (BRUSAG) Tracker

The INTRA (BRUSAG) Tracker

(Please note: The information on this page was adapteded from the company's brochure.)



With INTRA, you no longer have to follow an elaborate and difficult installation procedure. INTRA knows enough about astronomy to correct a misalignment with respect to the astronomical system simply by analysing the suns orbit. After two days with good weather conditions, INTRA has established an exact knowledge about its alignment parameters.

Accurate Timebase

INTRA keeps track of the time by taking into account thermally induced drifts of the crystal oscillator of its onboard clock. But there is more: Once INTRA has established the alignment parameters, it uses its solar observations and its knowledge in astronomy to keep the clock running accurately on universal time.

Unattended Operation

INTRA also helps keeping operational costs low, because its built in time keeping algorithm allows unattended operation during years. INTRA automatically recovers from powerfails shorter than 12 hours.

If equipped with the battery option, the duration of power- fail intervals that can be bridged becomes virtually unlimited.

Rugged Design

We designed INTRA to be a robust and reliable device. Its worm-drive gears are truIy backlash-free and its brush-less DC motors ensure a long life. INTRA is capable carrying loads up to 30 kg.


Easy Installation

Installation of INTRA is easy, because you do not have to accurately align it with the system of astronomical coordinates. All you need is a simple compass to approximately determine north-south direction and a terminal to enter time and site parameters and to command INTRA to perform an initialization sequence. INTRAs software menus guide you through the installation process.

The simple installation, which can be performed by untrained staff saves costs and reduces the time for the installation to an absolute minimum.

Moon and Satellites

can be tracked by computing positions on e. g. a PC and sending corresponding commands to INTRA, using its "remote-command" feature remember: INTRAs contribution to non- solar tracking is, that it "aligns" itself exactly with the system of astronomical coordinates.

All Weather Operation

INTRA is built to withstand the hardest outdoor conditions. The temperature may vary between -46C to +50C. All mechanical parts are stable enough to withstand high wind loads. And last, but not least - all electrical lines to and from INTRA are equipped with lightening protection circuits.


INTRAs documentation written in English accelerates the customers access to INTRAs essential features. The first part includes all the information one needs to install and operate INTRA. The second part gives full details on all aspects of INTRA.

Modular and Flexible

The base unit provides the minimum hardware for a solar tracking application. Depending on your needs you may add options and accessories, thereby advancing INTRA to handle even the most complex applications.

The list of options and accessories is steadily growing:

mounting pods, enhanced backuptime, heater, electrical interface box with or without power supply unit, shading disk mechanisms to operate INTRA for one, two or more pyranometers or pyrradiometers, interface clamps to accommodate normal incidence radiometers and/or sunphotometers.

The Complete Solution

INTRA has everything built in to perform solar tracking. All it needs is a 24 VDC power supply, no other external electronics or computer required!

Software Updates

INTRAs flash-ROM-resident software is permanently optimized and enhanced. Software updates can easily be downloaded using an IBMcompatible PC connected with a serial link to INTRAs controller.

The Company

BRUSAG is a small innovative company located near Zurich (Switzerland). BRUSAG develops, manufactures and sells meteorological sensors and instruments and offers engineering services in this and related fields.


 supply voltage: 10-30 VDC
  24 V nominal
 current (@24 v) (without heater)
 peak: 2 A max.
 operating: < 500 mA
 standby: < 50 mA
 serial interface: RS232-C, RS422 or RS485
  300..19200 bps,
  default is: 9600 bps, 8 data-, 1 stop-, no parity bit
 protection: All electrical lines are filtered and protected with 1.5 kW transorb-type diodes.

 mass: 30 kg (base unit)
 physical dim.: D x W x H (mm): 350 x 318 x 318 (base unit)
 configurations: "elevation over azimuth" or "azimuth over elevation"
 motors: brushless DC-Motor on each axis
 gears: backlashfree, worm-drive, ratio 150:1 coupled with 1:1 (toothed) belt drive to 66:1 gear which is directly coupled to the motor
 encoders: coding disks attached to primary- and secondary-axis resp., resolution: 9380 cnts per 360 degrees, corresponding to a resolution of 0.038 degree
 max. Capacity: 30 kg or 90 Nm shared among both flanges or 20 kg/60 Nm total on single flange
 max. speed: 100 degrees/minute (either axis )

 general: built for operational outdoor use
 temperature: -30C to 50C, -46C to 50C with heater option
 pointing: s < 0.1 degree after two days of operation during good weather conditions



For further information please contact:

Chapfwiesenstrasse 14 CH-8712 Stäfa (Switzerland)
Tel. +41 1 926 74 74 Fax +41 1 926 73 34