Unmanned integrated optical remote emissions sensor (RES) for motor vehicles

An integrated optical emissions sensor for sensing a gas mixture composition of an exhaust plume of a motor vehicle travelling along a road, comprising:

• a single console that is positioned at one side of the road;
• a vehicle detector in said console for sensing an oncoming vehicle and computing its acceleration;
• a source in said console for radiating a beam of light along a path across the road such that the beam passes through the exhaust plume of a passing vehicle and otherwise passes through ambient air;
• a reflector that is positioned on the other side of the road such that the beam reflects off of the reflector and back to the console;
• a receiver in said console sampling radiation levels at a plurality of predetermined wavelengths from the beam;
• a data processing computer in said console for computing a gas mixture composition from the sensed radiation levels in accordance with stored calibration curves;
• a canister in said console for emitting a puff of calibration gas in the path of the beam between the source and the receiver to recompute the calibration curves;
• a trigger device in said console that produces a trigger signal when a vehicle passes through the beam causing the data processing computer to record the gas mixture composition of the vehicle's exhaust plume for a period of time, said data processing computer disabling the recordation of the composition of the vehicle's exhaust plume when the acceleration exceeds a threshold;
• and
• a vehicle identification device in said console that responds to the trigger signal by recording a vehicle identification for the passing vehicle.

A remote emissions sensing system sensing gas mixture compositions of exhaust plumes for motor vehicles traveling along a network of roads, comprising:

• a plurality of unmanned integrated optical emissions sensors positioned at different places in the network on a side of the road, each emissions sensor comprising:
• a console;
• a vehicle detector in said console for sensing an oncoming vehicle and computing its acceleration;
• a source in said console for radiating a beam of light along a path across the road such that the beam passes through the exhaust plume of a passing vehicle and otherwise passes through ambient air;
• a reflector that is positioned on the other side of the road such that the beam reflects off of the reflector and back to the console;
• a receiver in said console that samples radiation levels at a plurality of predetermined wavelengths from the beam;
• a data processing computer in said console for computing a gas mixture composition from the sensed radiation levels in accordance with stored calibration curves;
• a canister in said console for emitting a puff of calibration gas in the path of the beam between the source and the receiver, said calibration gas having a known reference composition at the predetermined wavelengths;
• a trigger device in said console that produces a trigger signal when a vehicle passes through the beam causing the data processing computer to record the gas mixture composition of the vehicle's exhaust plume for a period of time, said data processing computer invalidating the recordation of the composition of the vehicle's exhaust plume when the acceleration exceeds a threshold;
• an automated control computer that
• a) calibrates the data processing computer by directing the canister to emit a puff of calibration gas, whereby the data processing computer recomputes the calibration curves in accordance with the known reference composition;
• b) verifies the calibration by directing the canister to emit a puff of calibration gas, whereby the data processing computer computes a test composition from the radiation levels and accepts the calibration when the test composition is close enough to the known reference composition and otherwise rejects the calibration and initiates recalibration;
• and
• c) monitors the gas mixture composition of the ambient air to control recalibration of the data processing computer;
• and
• a vehicle identification device in said console that responds to the trigger signal by recording a vehicle identification for the passing vehicle;
• a manned control center;
• and
• a communications channel for communication between the emissions sensors and the manned control center, said emissions sensors responding to repeated calibration rejections by transmitting a help message to the manned control center, which in turn responds by performing diagnostics to determine a cause for the calibration rejection and then either remedy the cause remotely or dispatch a technician to remedy the cause on site.