Systems and methods for inspection portals

An inspection portal for imaging an object, said inspection portal comprising:

• a first x-ray source configured to emit a first beam;
• a collimator defining an aperture configured to generate a transmission beam from the first beam;
• a transmission detector configured to detect transmission from the transmission beam;
• a second x-ray source configured to emit a second beam;
• a chopper wheel configured to generate a backscatter beam from the second beam, wherein said inspection portal is configured such that the transmission beam and the backscatter beam are incident on the object simultaneously;
• a backscatter detector configured to detect backscatter from the backscatter beam;
• and
• at least one collimator coupled to said backscatter detector, said at least one collimator positioned and oriented to prevent backscatter from the transmission beam from reaching said backscatter detector.

An inspection portal for imaging an object, said inspection portal comprising:

• a first x-ray source configured to emit a first beam towards the object;
• a first backscatter detector configured to detect backscatter from the first beam;
• a second x-ray source configured to emit a second beam towards the object;
• a second backscatter detector configured to detect backscatter from the second beam;
• and
• at least one first collimator coupled to said first backscatter detector and at least one second collimator coupled to said second backscatter detector, said at least one first collimator oriented to detect backscatter from the first beam and to block scatter from the second beam, and said at least one second collimator oriented to detect backscatter from the second beam and to block scatter from the first beam, wherein said first and second backscatter detectors each comprise a plurality of detector elements, wherein said first and second backscatter detectors are configured to weight signals acquired using each said detector element based on a current position of the first and second beams, wherein said first backscatter detector is configured to use signal processing techniques to mitigate crosstalk due to scatter from the second beam, and wherein said second backscatter detector is configured to use the signal processing techniques to mitigate crosstalk due to scatter from the first beam.