Opus AccuScan™ Remote Sensing Devices (RSD) remotely measure exhaust emissions from motor vehicles as they are driven past the remote sensing device on streets and highways. The emissions are measured spectroscopically by casting a narrow infrared (IR) and ultraviolet (UV) beam of light across the road and through the trailing exhaust of passing motor vehicles. A mirror then reflects the IR/UV light back to a series of detectors that measure the amount of transmitted light at characteristic wavelengths absorbed by the pollutants of interest.


The RSD can measure the emissions of vehicles circulating under real driving conditions. Since it takes only a second to capture a measurement, these devices can capture large quantities of vehicle emissions data in a short period of time.


Also, since it is a non-intrusive technique, the RSD audits the circulating vehicles without interfering with the traffic flow, therefore it can audit an entire city's fleet in a short period and with no impact on daily operations.


The RSDs can measure the traffic emissions remotely, without the vehicles having to stop to be audited.

exhaust emissions are measured instantly, accurately and non-intrusively

The RSD (Remote Sensing Device) is the only technology able to measure massively all traffic emissions (CO, CO2, HC, NOx, PM) as well as provide kinetic conditions and license plate picture of every vehicle driving by, all non-intrusively and instantly.


Opus RSE is the only entity in the world accredited to measure real-driving emissions remotely.

Systems are calibrated, our procedures and equipment are audited by the Spanish Acreditation agency every year.


The cheapest method to measure real-world traffic emissions. it is easy to obtain a return on investment if the RSD is implemented as a method to reduce traffic emissions.

real data

Obtain real emissions data for any individual vehicle.

It does not relies on projections or models.

See the real emissions emitted by each vehicle in real-time!


RSD correlate with other analytical devices such as PEMS and OBS by up to 95%.

It is a proven system to measure actual emitted exhaust emissions.

effective policy

High emitting vehicles must to be individually identified since 5% of the fleet contributes with over 50% of total emission.

closing the gap

Current emission control is not performed under real driving conditions and PTIs do not even test NOx or HC emissions.



Traffic emissions are measured continuously without affecting normal circulation. Each vehicle's emissions are analyzed in  0.5 seconds.


Deployed at strategic locations (mobile units) in 20 minutes. Easy to calibrate. Each unit can be monitored remotely (PC, smartphone, tablet).

worldwide recognition

The efficiency and versatility of remote sensing has been recognised by numerous scientific bodies, including the US-EPA, who has published three guides recognizing the benefits of the technology.


Opus RSE is adding value continuously to the technology by operating it under ISO Standards and working with the Spanish Government creating legislation among others.


Awards & Recognition +

history of rsd

Since 1989, ARB (California Air Resources Board) has sponsored several research studies that employed RSDs to measure on-road vehicle emissions at several California locations.

Those studies, carried out by Dr. Donald Stedman, Dr. Gary Bishop, and their team with the University of Denver (DU), started with CO measurement, with VOC, NO measurements an additional capabilities added over the years.


Learn more about RSD history +

how does it work?

The Remote Sensing Device (RSD) is able to measure vehicles emissions circulating under real driving conditions. It is a mobile system that can be deployed easily in strategical locations as required.

The RSD detects and measures each vehicle emissions as the vehicle drives by. The process of measuring emissions remotely begins when the vehicle breaks the infrared (IR) and ultraviolet (UV) beam sent across and back a single lane road from the Source/Detector Module (SDM) to a Corner Cube Mirror (CCM).


Since it can obtain a complete record in less than a second, these devices are designed to obtain large quantities of data per day. This generates a sufficient amount of reliable information to be extrapolated to the entire fleet circulating in a city. Also, since it is a non-intrusive technique, the RSD audits circulating vehicles without interfering with the traffic flow.


Due to the RSD is a mobile system, no special requirements are needed for setting it up on the road sides. Besides, RSD deployment is very simple and agile due to the minimal amount of components required to operate the system.

Main key components of the RSD are:


  • Emissions module (SDM + CCM)
  • Kinetic module (Speed/Accel Bar)
  • CCTV Camera
  • Weather Station module

For awareness campaigns, our Smart Sign is connected in order to display any information required to inform the drivers as they pass by the emissions detector


The RSD technology is an effective response to the need of improving the air quality in the European cities.


Big European cities are facing huge problems in terms of air quality. The on road traffic is the responsible of most of the emissions in the cities. It is proved that a small amount of vehicles (<10%), no matter the age or type, are responsible of a huge percentage of the total road emissions and by acting only on them, savings of millions of euros could be achieved.


The RSD Technology operated by Opus RSE is the best solution to attack these negative impacts provinding additional strategic advantages such as:


Improving air quality reducing the on road traffic emissions by monitoring & controlling their evolution with time.


Low budget implementation, savings in fuel consumption and EU penalties, public spending reduction and possible source of incomes.


Improving the air and quality of life, environmental awareness-raising and citizenship education.


Actions viewed favourably by the International Authorities in regards to global commitments on emissions reduction and air quality.