Abstract: Detection and sampling of dissolved hydrocarbons of interest in an environment expected to have hydrocarbon molecules, such as a water column or interstitial water in sediment. An apparatus comprising at least one oleophilic film frame is deployed into the environment and the at least one oleophilic film frame is exposed thereto for a defined period of time, and thereafter isolated from the environment to cease exposure thereto. Hydrocarbon molecules scavenged by the oleophilic film may be analyzed to determine their type and/or concentration.

Abstract: Detection and sampling of dissolved hydrocarbons of interest in an environment expected to have hydrocarbon molecules, such as a water column or interstitial water in sediment. An apparatus comprising at least one oleophilic film frame is deployed into the environment and the at least one oleophilic film frame is exposed thereto for a defined period of time, and thereafter isolated from the environment to cease exposure thereto. Hydrocarbon molecules scavenged by the oleophilic film may be analyzed to determine their type and/or concentration.

Abstract: An apparatus is provided that includes a plurality of reflectors arranged over an area, and a plurality of transceivers. A first of the transceivers is configured to transmit radiation at each of the plurality of reflectors at a first wavelength and a second wavelength, and receive radiation reflected from each of the plurality of reflectors. A second of the plurality of transceivers is configured to transmit radiation at each of the plurality of reflectors at a third wavelength and a fourth wavelength and receive radiation reflected from each of the plurality of reflectors. The apparatus includes a processor configured to calculate a change in concentration of a gas within the area between a first time and a second time based upon signals received from the transceivers.

Abstract: Remote absorption spectroscopy uses coded electromagnetic transmission directed through a medium under investigation to one or more remote receivers. The coded transmission includes at least one wavelength coincident with an absorption band of interest and one wavelength in an off-line band and a predefined relationship between spectral components in and outside the absorption band is controlled. The relationship between spectral components may be evaluated at the receiver to determine whether deviation thereof from the controlled relationship at the transmitter exists at the receiver. The deviation of the received optical signal from the prescribed relationship is processed to indicate the absorption of the radiation in the absorption band.

Abstract: Remote absorption spectroscopy uses coded electromagnetic transmission directed through a medium under investigation to one or more remote receivers. The coded transmission includes at least one wavelength coincident with an absorption band of interest and one wavelength in an off-line band and a predefined relationship between spectral components in and outside the absorption band is controlled. The relationship between spectral components may be evaluated at the receiver to determine whether deviation thereof from the controlled relationship at the transmitter exists at the receiver. The deviation of the received optical signal from the prescribed relationship is processed to indicate the absorption of the radiation in the absorption band.

Abstract: A lock-in ratio measurement system including a plurality of channels. Each of the channels generates and transmits a radiation signal modulated by a sequence of tones. The sequence of tones for each channel being unique in time to that respective channel. Each respective modulated signal is absorbed/reflected from a target or medium and received. Each channel computes a lock-in value based on the received modulation signal. The lock-in values are used to compute ratios between the channels for characterizing a target or medium.