Vehicle-based dual-comb spectrometer measurement

Abstract

To provide a system and a method for vehicle-based dual-comb spectrometer measurement.SOLUTION: A system 300 includes a vehicle having a body with at least one aperture formed therein and a vehicle surface. The system includes a dual-comb spectrometer 307 mounted in the body. The dual-comb spectrometer emits dual-comb optical signals through the at least one aperture toward an external surface 313 that is not part of the vehicle surface. The dual-comb spectrometer receives, through the at least one aperture, reflected optical signals corresponding to the dual-comb optical signals reflected by the external surface. Further, the system includes one or more processors 303 that produce measurements of the average concentration of at least one particle within a volume 315 between the vehicle and the external surface on the basis of spectroscopic information from the reflected optical signals.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the benefit of U.S. Patent Application No. 63 / 607,912, filed on December 8, 2023, and U.S. Patent Application No. 63 / 609,777, filed on December 13, 2023, and the entire contents of each of the foregoing patent applications are hereby incorporated by reference as if fully set forth herein.

Background Art

[0002] The change of the Earth's climate has a great impact on many interconnected systems operating on the Earth. Changes in ecosystems, precipitation patterns, and sea levels can affect whether species can survive on the planet we share. Understanding how the climate will change can help us prepare for, adapt to, or mitigate the effects of these changes. However, the climate is a complex and vast interconnected system that is difficult to accurately model. One challenge in modeling such a system is collecting sufficient data across the entire climate. With insufficient data, it is difficult to create a useful climate model.

Summary of the Invention

[0003] Systems and methods for vehicle-based dual-come spectroscopic measurements are described herein. In certain embodiments, the system includes a vehicle having a body with at least one aperture formed therein and a vehicle surface. The system also includes a dual-come spectrometer mounted on the body, the dual-come spectrometer being configured to emit a dual-come optical signal through the at least one aperture toward an external surface that is a surface other than a portion of the vehicle surface, and the dual-come spectrometer being configured to receive a reflected optical signal corresponding to the dual-come optical signal reflected by the external surface through the at least one aperture. Further, the system includes one or more processors configured to create a measurement of an average concentration of at least one particle within a volume between the vehicle and the external surface based on spectroscopic information from the reflected optical signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The figures are provided with the present specification and show only some embodiments related to the appended claims. Accordingly, the described and illustrated embodiments should not be considered as limiting the scope. The accompanying drawings and description explain exemplary embodiments and their features with further specificity and detail.

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[0005] In accordance with convention, the drawings do not show the various features to scale, but the drawings do show features for emphasizing the relevance to exemplary embodiments of the features.

Mode for Carrying Out the Invention

[0006] The following detailed description refers to the accompanying drawings that form a part of this specification. The drawings show, by way of example, specific exemplary embodiments. However, it should be understood that other embodiments may be used and logical, mechanical, and electrical changes may be made.

[0007] A system and method for vehicle-based dual-comb spectroscopic measurements are described herein. In certain embodiments, a dual-comb spectrometer (DCS) is mounted on a vehicle. As the vehicle passes through an environment, the vehicle may emit an optical signal to survey an environmental volume between the vehicle and an external non-vehicle surface. As the optical signal passes through the volume, the optical signal is absorbed, scattered, and reflected by different molecules and particles within the volume. The optical signal then reflects off the external surface and is received by the DCS on the vehicle, passing through the volume again for survey. Based on the composition of the volume, the optical signal received by the DCS contains spectroscopic information indicative of the average composition of the surveyed volume.

[0008] As described above, collecting environmental information is important for conducting atmospheric analysis and climate prediction. For example, a vehicle such as an airplane may have a DCS mounted on the body of the airplane. As the airplane passes through the environment, the DCS may emit an optical signal to investigate the volume of the atmosphere between the airplane and the ground below the airplane. When the optical signal returns after being reflected by the ground, the optical signal can be detected and analyzed to identify spectroscopic information regarding the investigated volume. From the spectroscopic information, a system on the aircraft or another system communicating with the aircraft may identify the average composition of the investigated volume. For example, the spectroscopic information may indicate the average amounts of greenhouse gases (such as water vapor, methane, N2O, CO2, CO, O3, etc.), particulate matter, or other measurements of environmental data. Next, a central system can use the measurements of environmental data obtained from the spectroscopic information, together with measurements obtained from other investigations by similar systems, to obtain a more comprehensive understanding of the composition of the atmosphere. The understanding obtained can improve the ability to predict and mitigate undesirable climate change.

[0009] Figure 1 is a diagram of an environment 100 through which a plurality of vehicles pass, collecting environmental data using a vehicle-based dual-com spectrometer. As shown, environment 100 may include a plurality of atmospheric volumes between the vehicle and the external surface. As described herein, an atmospheric volume is a volume that includes a portion of the atmosphere. Thus, an atmospheric volume includes the gases and particulate matter floating within the volume. As the vehicle moves, the vehicle passes through environment 100. Examples of vehicles include airplane 101 (such as an airplane, helicopter, missile, drone, etc.), spacecraft 103 (such as a rocket, satellite, etc.), ground vehicle 107, ship 113, and the like.

[0010] In certain embodiments, a vehicle moving within environment 100 is equipped with a DCS for emitting an optical signal toward an external surface that is not part of the vehicle surface to measure the average composition of the atmospheric volume between the vehicle and the surface. For example, the first aircraft 101a may emit an optical signal toward the external surface 109. The emitted optical signal then passes through the volume between the aircraft 101a and the external surface 109, where molecules and particles can reflect, absorb, and scatter the emitted optical signal. The emitted optical signal then reflects off the external surface 109, passes through the volume again, and is received by the DCS. The received optical signal can then be detected for processing, and subsequent processing can identify the composition of the volume between the aircraft 101a and the external surface 109 based on the spectral information of the received optical signal.

[0011] In a further embodiment, when processing the detected optical signal reflected from the surface, the processing may take into account information regarding the surface that reflects the emitted optical signal. For example, the external surface 109 is an example of a rocky terrain, and the surface 111 is an example of a water terrain. Thus, the vehicle may store information regarding the type of surface that reflects the emitted signal. For example, the aircraft 101b may store a terrain database that associates the current position of the vehicle with the surface directly below the vehicle. Alternatively, the vehicle may include additional sensors, such as visual sensors, that enable a computer on the aircraft 101b to identify the type of surface that reflects the emitted optical signal.

[0012] In an additional embodiment, when the vehicle receives a reflected light signal, the detector may receive the detected signal and generate an electrical signal that includes spectral information for subsequent processing. The spectral information includes measurements of the amplitudes of the different wavelengths of light received in the reflected light signal. In some implementations, a computer on the vehicle may perform subsequent processing to generate a measurement of the average composition of the volume from the spectral information. Alternatively, a communication system on the vehicle may transmit the spectral information to another system that performs subsequent processing. However, some data links may not support the data rate or have associated costs, thereby making the transmission of the spectral information infeasible. Further, the spectral information may be stored in a memory device, in which case the spectral information can be downloaded directly by another system or through another communication system, and this other system performs subsequent processing.

[0013] In certain embodiments, the subsequent processing creates measurements of the average concentrations of specific molecules and particulates. For example, the measurements may identify the average concentrations of water vapor, methane, N2O, CO2, CO, O3, etc. within the volume under investigation. In some implementations, the measurements may be provided to a control center 105 or some other center that uses the measurements for a desired purpose. For example, the control center 105 may accumulate measurements from multiple vehicles to collect information about the environment 100, expand climate models, and provide inputs to existing climate models. When providing information to the control center 105, the vehicle may transmit the measurements immediately after calculation through a communication link. For example, the aircraft 101a may transmit information through a wireless communication link. The aircraft 101 may transmit the information directly to the control center 105 or through a transmission relay. In at least one instance of relaying information to the control center 105, the aircraft 101b may transmit the information to a spacecraft 103 (such as a satellite), and the spacecraft 103 transmits the information to the control center 105. Alternatively, the aircraft 101b may transmit the information to another aircraft such as the aircraft 101a, and this other aircraft then relays the information to the control center 105.

[0014] In an alternative embodiment, the aircraft 101a may store the measurement values until the aircraft 101a approaches the control center 105, or the measurement values may be provided to the control center 105 using a less expensive communication link, a communication link controlled by an operator associated with the control center 105, or the measurement values may be stored until the aircraft 101a comes to a position where the measurement values are transferred to a portable computer-readable medium that is physically delivered to the control center 105.

[0015] In an additional embodiment, while the measurement of the volume composition has been described with respect to the aircraft 101a, other vehicles may also survey the volume in the environment. For example, the vehicles may include a spacecraft 103, a barge 107, a ship 113, and the like. For example, the barge 107 and the ship 113 may aim the emitted optical signal towards a surface within the environment 100. For example, the barge 107 may aim the emitted optical signal towards a mountain, a building, another vehicle, or another surface. Similarly, the ship 113 may also aim the emitted optical signal towards a mountain, a building, another vehicle, or another object having a surface. The spacecraft 103 may emit a signal from space towards the surface, similar to the aircraft 101a and 101b.

[0016] Thus, as the vehicles move through the environment 100, different vehicles may survey the volume within the environment 100 using the optical signals emitted and received by the DCSs mounted on the respective vehicles. Measurement values are created and provided to the control center 105, and the control center 105 uses the measurement values as inputs for a climate prediction model or an improvement model.

[0017] Figure 2 is a block diagram of a system 200 for obtaining environmental measurement values from a vehicle-based DCS. As shown, system 200 includes a vehicle computer 201 and a DCS sensor 207. The vehicle computer 201 receives sensor data from the DCS sensor 207. The vehicle computer 201 may calculate measurements of the average concentration of different gases and particulate matter based on the sensor data, or the vehicle computer 201 may relay the received sensor data to a control center 209. The control center 209 may use the data as an input for a climate prediction model or an improvement model.

[0018] The vehicle computer 201 may include a processor 203 and a memory 205. In certain embodiments, the processor 203 executes instructions that can direct the processor 203 to process sensor data from the DCS sensor 207 to calculate a measurement of the average concentration. The instructions may also direct the processor 203 to transmit the calculated measurement and / or the sensor data to other systems, or to store the measurement and / or the sensor data in the memory 205. As described herein, the processor 203 may be a single processor or a device that includes a combination such as a general-purpose processor, a multi-core processor, multiple processors, a dedicated circuit, etc. The functions performed by the processor 203 may be implemented using software, firmware, hardware, or any suitable combination thereof. The processor 203 and other computing devices may be supplemented by or incorporated into a specially designed application-specific integrated circuit (ASIC) or a field programmable gate array (FPGA). The processor 203 and other computing devices may also include or be operable by software programs, firmware, or other computer-readable instructions for performing the various process tasks, calculations, and control functions used in the method and system.

[0019] Furthermore, the methods described herein may be implemented by computer-executable instructions, such as program modules or components executed by the processor 203 and other computing devices. Generally, program modules include routines, programs, objects, data components, data structures, algorithms, and the like that perform particular tasks or implement particular abstract data types.

[0020] In addition to the processor 203, the vehicle computer 201 also includes a memory 205. The memory 205 may be any suitable computer-readable storage medium, and computer-readable storage media include, for example, semiconductor memory devices such as random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), or flash memory devices; magnetic disks such as internal hard disks or removable disks; optical storage devices such as compact discs (CDs), digital versatile discs (DVDs), Blu-ray discs, or other media capable of carrying or storing the desired program code as computer-executable instructions or data structures, including non-volatile memory devices. Further, in addition to storing instructions for execution by the processor 203, the memory 205 may also store a repository for a specified group of data. For example, the memory 205 includes dedicated memory for storing calculated measurement values and a database of information that assists the processor 203 when processing sensor data. Specifically, the memory 205 may include a measurement value repository 211, a terrain database 213, and / or a particle model 223.

[0021] In some implementations, system 200 may also include a vision sensor 219 and / or a position sensor 221. As used herein, vision sensor 219 includes sensors that acquire information about the environment from captured images of the environment. The captured images may include two-dimensional or three-dimensional data. Processor 203 may use the two-dimensional or three-dimensional data included in the captured images to identify the position and orientation of the vehicle from the image data using methods known to those skilled in the art, or may identify the position and / or orientation of the vehicle. Alternatively, processor 203 may identify the type of surface that reflects the emitted optical signal. For example, processor 203 may determine whether the reflective surface is sand, shade, water, snow, rock, grassland, or other type of surface type.

[0022] Regarding position sensor 221, position sensor 221 may provide position measurements or data that can be used by processor 203 to identify the position and / or orientation of the vehicle. For example, position sensor 221 may include a global navigation satellite system (GNSS) receiver, an inertial sensor, a magnetometer, an altimeter, a barometer, and the like. In some implementations, system 200 includes both a position sensor 221 and a vision sensor 219, where position sensor 221 is used to obtain the position of the vehicle and vision sensor 219 is used to obtain the surface type that reflects the surface type.

[0023] In certain embodiments, the processor 203 may receive measurements from the DCS sensor 207 that include spectroscopic measurements of the interrogation volume. The position sensor 221 and the vision sensor 219 may provide information about the position of the vehicle, and the vision sensor 219 may provide information that can be used to identify the type of reflective surface. In some implementations, the processor 203 may use information about the type of reflective surface to characterize the interaction between the reflective surface and the emitted light. By characterizing the interaction between the surface and the emitted light, the processor 203 may separate information within the spectroscopic information associated with the reflection of the emitted light by the reflective surface from information within the spectroscopic information associated with the composition of the interrogation volume.

[0024] When the processor 203 separates a portion of the spectroscopic information associated with the composition of the interrogation volume, the processor 203 may analyze the separated data within the spectroscopic information received from the DCS sensor 207 to identify the composition of different gases. For example, for a particular molecule or particle, the processor 203 may compare the spectroscopic information to particle models stored in the particle model 223. The particle model 223 may store multiple models of different compositions of a particular particle or molecule. The processor 203 may then compare the spectroscopic information to the multiple models to identify the model that is closest to the spectroscopic information. For example, the processor 203 may correlate the received information with different stored models and use the model with the highest correlation to identify the average composition of the interrogation volume for the modeled particle. The particle model 223 may store models of multiple particles and molecules, and the processor 203 may identify the average composition of multiple particles and molecules for the interrogation volume. In an alternative embodiment, the processor 203 may directly calculate the average composition from the spectroscopic information without using the data stored in the particle model 223.

[0025] In an alternative embodiment, the processor 203 may acquire information about the type of the reflecting surface from the terrain database 213. For example, the terrain database 213 may store information about terrain types associated with specific geographical locations. Therefore, the processor 203 may identify the location based on the information from the position sensor 221 and then identify the terrain type associated with the location stored in the terrain database 213. In some implementations, the processor 203 uses the information in the terrain database 213 in combination with the information received from the visual sensor 219 to characterize the terrain type.

[0026] When the processor 203 calculates a measured value of the average composition of the investigation volume, the processor 203 may provide the information to the control center 209 for further analysis. In some implementations, the processor 203 provides the measured value to the control center 209 through the communication interface 215. As used herein, the communication interface 215 is a communication link interface that enables the vehicle computer 201 to communicate through a communication link. For example, the communication interface 215 may interface with a SATCOM, VHF, 5G, IP, or other type of communication link. Additionally, the communication interface 215 may transmit the measured value to the control center 209 through the relay system 217. The relay system 217 then relays the received measured value to another relay system or directly to the control center 209. For example, an aircraft may relay a measured value to the control center 209 through another aircraft using an ADS - B communication link. In some embodiments, if the communication link supports a sufficient data rate, the vehicle computer 201 may transmit spectroscopic information to the control center 209, in which case the control center 209 then calculates the composition measurement value of the investigation volume.

[0027] In an additional embodiment, the processor 203 may store the spectral information, the calculated measurements, and / or the positions associated with the acquired spectral information in the measurement repository 211. For example, potentially, if the communication interface 215 cannot communicate with the control center 209 or relay the measurements to the control center 209, the processor 203 may store the data in the measurement repository 211. When the vehicle can establish a communication link with the control center 209 (e.g., when landing or moving within the coverage area associated with the communication link), the processor 203 may transmit the stored measurements and data to the control center 209 through the communication interface 215, through a direct connection to the control center 209, or by physically moving the measurement repository from the vehicle to the control center 209. Using data from the vehicle computer 201 and other similar vehicle computers, the control center 209 may provide higher-quality inputs to the climate model. Additionally, the data may be used to improve the climate model.

[0028] FIG. 3 is a diagram showing a dual-comb spectrometer sensor system 300 used in the above-described system. As shown, system 300 includes two parts: an optical domain component 301 and an RF / digital domain 303. As shown, the optical domain component 301 includes an optical signal source 305 that generates two optical frequency combs. Examples of potential optical signal sources include a fiber laser 327, a photonics chip 329, or other potential laser sources. To generate two optical frequency combs, the optical signal source 305 may include a first comb source 307-1 that generates a first optical frequency comb 309-1 and a second comb source 307-2 that generates a second optical frequency comb 309-2. Optionally, the first optical frequency comb 309-1 and the second optical frequency comb 309-2 are phase-locked to each other. Each optical frequency comb includes spectral components within the optical spectrum. Each pair of adjacent spectral components of each optical frequency comb is separated by a fixed frequency. However, such fixed frequency separation is different between the first optical frequency comb 309-1 and the second optical frequency comb 309-2. The fixed frequency separation of the first optical frequency comb 309-1 is the first separation frequency f s is. The fixed frequency separation of the second optical frequency comb 309-2 is the second separation frequency f s +Δf. Δf is sometimes referred to as the offset frequency. Optionally, the first separation frequency f s is at least four orders of magnitude greater than the offset frequency Δf.

[0029] As shown, a first optical frequency comb 309-1 and a second optical frequency comb 309-2 are combined using optical components 311-1 and 311-2. The optical components 311-1 and 311-2 may include optical components that combine the first optical frequency comb 309-1 and the second optical frequency comb 309-2 and direct them towards a reflective surface through an interrogation volume. For example, the optical components 311-1 and 311-2 may include mirrors, partial reflectors, polarizers, waveplates, collimators, etc. The first optical frequency comb 309-1 and the second optical frequency comb 309-2, when combined, are emitted from an aperture of the vehicle. The first optical frequency comb 309-1 and the second optical frequency comb 309-2, when emitted from the aperture, pass through a volume 315 between the vehicle and the reflective surface and are incident on a surface 313. The reflective surface 313 reflects the first optical frequency comb 309-1 and the second optical frequency comb 309-2 back towards the vehicle, and they pass through the aperture and are incident on a photodetector 317.

[0030] In certain embodiments, the photodetector 317 receives the reflected first optical frequency comb 309-1 and second optical frequency comb 309-2 after each has propagated twice through the interrogation volume 315. The photodetector 317 generates, for example, an electrical signal representing a heterodyne beat frequency comb in a radio spectrum lower than the optical spectrum. The photodetector 317 then provides the electrical signal to the RF / digital domain 303.

[0031] Within the RF / digital domain 303, an electrical signal is received by a processing circuit 319 that generates spectral information 325. The processing circuit 319 may include an FPGA, a CPU, or other computing device. Additionally, the processing circuit 319 may include additional circuitry to facilitate processing of the signal received from the photodetector 317. For example, since the signal created by the photodetector 317 may be an analog electrical signal, the processing circuit 319 may include an analog-to-digital converter (ADC) 321 to convert the detected signal to the digital domain. Further, the processing circuit 319 may include a processor 323 that generates spectral information 325 from the digital signal. The processor 323 may function similarly to the processor 203 of FIG. 2. Alternatively, the processing may be performed by the processor 203 of FIG. 2. When the spectral information 325 is generated, a processor (such as the processor 203) may perform additional processing to obtain measurements of particles and molecules contained within the interrogation volume 315, as described above.

[0032] FIG. 4 is a flowchart diagram of a method 400 for providing vehicle-based dual-comb spectroscopy measurements. In certain embodiments, the method 400 proceeds to 401 where a dual-comb optical signal is emitted towards an external surface through at least one aperture on a vehicle, and the space between the vehicle and the external surface defines a volume. Also, the method 400 proceeds to 403 where a reflected optical signal is received through at least one aperture, the reflected optical signal corresponding to the dual-comb optical signal reflected by the external surface. Additionally, the method 400 proceeds to 405 where the reflected optical signal is detected and an electrical signal representing the information within the reflected optical signal is generated.

[0033] In an additional embodiment, method 400 proceeds to 407 where spectral information is generated from an electrical signal. In some implementations, the emitted signal is reflected by an external surface, and the topography of the external surface affects the spectral information in addition to the effect of particles in the volume of air between the vehicle and the external surface. Thus, generation of the spectral information may include characterizing the topography type of the external surface and removing spectral information from the electrical signal associated with the characterized topography type.

[0034] In some implementations, the topography type may be characterized using a position sensor that helps identify the position and orientation of the vehicle, in conjunction with a topography database that associates the topography type with different locations on the external surface (such as the surface of the earth). Thus, after identifying the position and orientation of the vehicle, a processor (on the vehicle or at a control center) may use the position and orientation to identify the location on the external surface that reflects the emitted signal back to the vehicle. The processor may then identify the topography type associated with the identified location on the external surface within the topography database. Once the topography type is identified, the processor may remove spectral information from the electrical signal associated with the topography type with respect to the position and orientation of the vehicle.

[0035] In an alternative implementation, the topography type may be characterized using an image sensor located on the vehicle. In particular, the image sensor on the vehicle may emit one or more optical signals towards the external surface. The received optical signal may be detected, and the resulting electrical signal may be processed to identify the topography type from the collected image data. For example, the image data may be compared to an image database such as a satellite image database, or the image data may be directly analyzed to identify the topography type. Once the topography type is identified, the processor may remove spectral information from the electrical signal associated with the topography type represented in the image data.

[0036] In certain embodiments, method 400 proceeds to 409 where a measured value of the average concentration of at least one particle within a volume is calculated based on spectroscopic information. Additionally, when calculating the measured value, the spectroscopic information may be provided to a control center, and at least one processor located at the control center calculates the measured value of the average concentration, or at least one processor located on the vehicle performs the calculation. If the information is provided to the control center and the information is spectroscopic information or a measured value calculated by an in-vehicle processor, the information may be transmitted from the vehicle to the control center through one or more communication interfaces. In some implementations, if the vehicle is not communicating directly with the control center, the information may be relayed to the control center through transmission from the vehicle to a relay system. The relay system may include other vehicles, relay stations, etc. Alternatively, the information may be stored on a physical storage medium on the vehicle, and the physical storage medium may be provided to the control center when convenient.

[0037] In additional embodiments, calculating a measured value of the average concentration of at least one particle, either in the vehicle or at the center, includes obtaining a plurality of particle models, where the particle models represent expected spectroscopic information for a particular concentration of the particles. The processor may then compare the spectroscopic information with the stored particle models to identify which of the particle models of the particles most closely correlates with the spectroscopic information. When the processor identifies the particle model with the highest correlation, the processor may determine that the average concentration of the most highly correlated particle model is the approximate average concentration of the particles within the investigated environmental volume.

[0038] Exemplary embodiments Example 1 is a system that includes a vehicle having a body with at least one opening formed therein and a vehicle surface, and a dual-comb spectrometer mounted on the body. The dual-comb spectrometer is configured to emit a dual-comb optical signal through at least one opening toward an external surface that is not a part of the vehicle surface, and the dual-comb spectrometer is configured to receive a reflected optical signal corresponding to the dual-comb optical signal reflected by the external surface through at least one opening. The system also includes one or more processors configured to create a measurement value of an average concentration of at least one particle within a volume between the vehicle and the external surface based on spectroscopic information from the reflected optical signal.

[0039] Example 2 includes the system of Example 1, and at least one particle is at least one of water vapor, methane, nitrous oxide, carbon dioxide, carbon monoxide, and ozone.

[0040] Example 3 includes the system of either Example 1 or 2, and at least one of the one or more processors is located on the vehicle, and the at least one processor creates the measurement value.

[0041] Example 4 includes the system of any one of Examples 1 to 3, and further includes one or more communication interfaces. The data transmitted through the one or more communication interfaces includes at least one of the spectroscopic information, and the measurement value of the average concentration is transmitted to a control center through the one or more communication interfaces.

[0042] Example 5 includes the system of Example 4, and the data transmitted through the one or more communication interfaces is transmitted to a relay system that relays the data to the control center.

[0043] Example 6 includes the system of either Example 4 or 5. The spectroscopic information is transmitted to the control center, and the one or more processors are located at the control center and create the measurement value from the spectroscopic information transmitted through the one or more communication interfaces.

[0044] Example 7 includes the system of any one of Examples 1 to 6, and further includes one or more position sensors configured to determine the position and orientation of the vehicle, and a memory configured to store a terrain database. At least one of the one or more processors is configured to identify the terrain associated with the external surface based on the terrain information stored in the terrain database associated with the position and orientation of the vehicle, and at least one processor adjusts the spectral information based on the terrain.

[0045] Example 8 includes the system of any one of Examples 1 to 7, and further includes a memory configured to store one or more particle models. At least one of the one or more processors is configured to identify the average concentration of at least one particle by correlating the spectral information with the one or more particle models.

[0046] Example 9 includes the system of any one of Examples 1 to 8, and one or more processors are configured to directly calculate the average concentration of at least one particle from the spectral information.

[0047] Example 10 includes the system of any one of Examples 1 to 9, and further includes one or more visual sensors configured to provide image information of the external surface. At least one of the one or more processors is configured to identify the surface type of the external surface, and at least one processor adjusts the spectral information based on the surface type.

[0048] Example 11 includes a method that includes emitting a dual-comb optical signal toward an external surface through at least one opening on a vehicle, where the external surface defines a volume between the vehicle and the external surface and is not part of the surface of the vehicle; receiving, through the at least one opening, a reflected optical signal corresponding to the dual-comb optical signal reflected by the external surface; detecting the reflected optical signal and generating an electrical signal representing information within the reflected optical signal; generating spectral information from the electrical signal; and calculating a measured value of an average concentration of at least one particle within the volume based on the spectral information.

[0049] Example 12 includes the method of Example 11, and calculating the measured value of the average concentration further includes providing the spectral information to a control center, and the measurement of the average concentration is performed by at least one processor located at the control center.

[0050] Example 13 includes the method of either Example 11 or 12, and further includes providing at least one of the spectral information and the measured value of the average concentration to the control center through at least one of transmitting at least one of the spectral information and the measured value of the average concentration to the control center through one or more communication interfaces; storing at least one of the spectral information and the measured value of the average concentration in a vehicle memory and providing at least one of the spectral information and the measured value to the control center when the vehicle is in proximity to the control center.

[0051] Example 14 includes the method of Example 13, and transmitting at least one of the spectral information and the measured value of the average concentration to the control center further includes transmitting at least one of the spectral information and the measured value toward the control center through a relay system.

[0052] Example 15 includes any of the methods of Examples 11 to 14, and generating spectral information further includes identifying the position and orientation of the vehicle using one or more position sensors located on the vehicle, identifying the terrain type in a terrain database associated with the position and orientation of the vehicle with respect to the external surface, and removing the terrain spectral information associated with the terrain type from the spectral information.

[0053] Example 16 includes any of the methods of Examples 11 to 15, and generating spectral information further includes obtaining image information of the external surface through one or more visual sensors located on the vehicle, identifying the terrain type based on the image information, and removing the terrain spectral information associated with the terrain type from the spectral information.

[0054] Example 17 includes any of the methods of Examples 11 to 16, and calculating the measured value of the average concentration of at least one particle includes obtaining a plurality of particle models, where the particle models represent the predicted spectral information for a specific concentration of the particles, correlating the spectral information with the plurality of particle models, and calculating the measured value of the average concentration based on the correlation between the spectral information and the plurality of particle models.

[0055] Example 18 includes any of the methods of Examples 11 to 17, and at least one particle is at least one of water vapor, methane, nitrous oxide, carbon dioxide, carbon monoxide, and ozone.

[0056] Example 19 is a system that includes a vehicle having a body with at least one opening formed therein and a vehicle surface, one or more sensors configured to acquire at least one of visual information of the vehicle and position and orientation information, one or more communication interfaces for communicating with one or more other systems, a dual-comb spectrometer mounted on the vehicle body, the dual-comb spectrometer being configured to emit a dual-comb optical signal through at least one opening toward an external surface that is not a part of the surface, the dual-comb spectrometer being configured to receive a reflected optical signal corresponding to the dual-comb optical signal reflected by the external surface through at least one opening, one or more processors configured to create a measurement of the average concentration of at least one particle in a volume between the vehicle and the external surface based on spectroscopic information from the reflected optical signal, and a memory configured to store at least one of a repository of measurements of the average concentration, a terrain database, and a plurality of particle models.

[0057] Example 20 includes the system of Example 19, and the one or more processors use at least one of visual information and position and orientation information to identify terrain spectroscopic information associated with the terrain of the external surface and remove the terrain spectroscopic information from the spectroscopic information from the reflected optical signal before the one or more processors create a measurement of the average concentration of at least one particle.

[0058] Although specific embodiments are illustrated and described herein, it will be understood by those skilled in the art that any configuration that is predicted to achieve the same purpose may be used instead of the specific embodiments shown. Thus, it is clearly intended that the present invention be limited only by the claims and their equivalents.

Claims

1. 1. A system comprising: a vehicle having a body and a vehicle surface with at least one opening formed therein; a dual comb spectrometer (207) mounted on the body, the dual comb spectrometer (207) configured to emit a dual comb optical signal through the at least one aperture toward an external surface (313) that is a surface that is not part of the vehicle surface, and the dual comb spectrometer (207) configured to receive a reflected optical signal corresponding to the dual comb optical signal reflected by the external surface (313) through the at least one aperture; and one or more processors (203) configured to generate a measurement of an average concentration of at least one particle within a volume (315) between the vehicle and the exterior surface (313) based on spectroscopic information (325) from the reflected light signal.

2. a memory (205) configured to store one or more particle models (223); 2. The system of claim 1, wherein at least one of the one or more processors (203) is configured to identify the average concentration of the at least one particle by correlating the spectroscopic information (325) with the one or more particle models (223).

3. 1. A method comprising: emitting a dual-comb optical signal through at least one opening on a vehicle toward an exterior surface (313), a surface that is not part of a surface of the vehicle, where a space between the vehicle and the exterior surface (313) defines a volume (315); receiving, through the at least one aperture, a reflected optical signal corresponding to the dual comb optical signal reflected by the exterior surface (313); detecting the reflected optical signal to generate an electrical signal representative of information in the reflected optical signal; generating spectroscopic information (325) from the electrical signal; and calculating a measure of an average concentration of at least one particle in the volume based on the spectroscopic information (325).

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