Optical and laser differential absorption remote detection of TATP peroxide based explosives
A triacetone triperoxide cloud associated with a triacetone triperoxide explosive attached to a hard target is remotely detected by operating differential-absorption lidar lasers to transmit a laser beam toward the hard target at differing wavelengths. A backscattered laser beam reflected from the lidar target (hard target, person, aerosols, clouds, buildings) is detected because a cloud of triacetone triperoxide in front of the lidar target and between the lidar target and the differential-absorption lidar system produces a differential-absorption signal having characteristics that identify the triacetone triperoxide. In a second embodiment, a triacetone triperoxide cloud that is absorbing optical radiation from its ambient environment and which is attached to a hard target is detected from a location remote from the triacetone triperoxide explosive by detecting an optical radiation absorption signature characterized by triacetone triperoxide absorption lines.
1. A method for remotely detecting a triacetone triperoxide cloud having a large optical absorption coefficient (i.e., optical absorption cross section) associated with a triacetone triperoxide explosive attached to a person comprising the steps of:
employing a differential-absorption lidar system including differential-absorption lidar lasers to transmit a laser beam toward the person;
operating the differential-absorption lidar lasers at differing wavelengths during said transmission of said laser beam;
detecting a backscattered laser beam reflected from the person;
detecting a backscattered laser beam reflected from an atmospheric aerosol lidar target or atmospheric cloud lidar target; and
detecting a cloud of triacetone triperoxide having a large optical absorption coefficient (i.e., optical absorption cross section) in front of the person and between the person and the differential-absorption lidar system by receiving a differential-absorption signal having characteristics that identify the triacetone triperoxide.
2. The method of claim 1 , further comprising the step of:
operating a line tunable CO 2 laser near 10.2 to 10.6 micron wavelength.
3. The method of claim 1 , further comprising the step of:
employing a tunable quantum cascade laser operating near 8.2 micron wavelength.
4. The method of claim 1 , further comprising the step of:
operating a quantum cascade laser near 3.3 micron wavelength.
5. The method of claim 1 , further comprising the step of:
operating an optical parametric oscillator laser or frequency mixed laser near 3.3 micron, 8.2 micron, or 10.6 micron wavelength.
6. A method for remotely detecting a triacetone triperoxide cloud having a large optical absorption coefficient (i.e., optical absorption cross section) associated with a triacetone triperoxide explosive attached to a person, said triacetone triperoxide cloud absorbing optical radiation from its ambient environment, comprising the steps of:
operating a differential-absorption lidar laser having a wavelength near 3.3 microns, 7.3 microns, 8.2 microns, 10.6 microns, or 11.2 microns to transmit a laser beam toward said person;
detecting an optical radiation absorption signature characterized by triacetone triperoxide's large absorption coefficient (i.e., optical absorption cross section).
7. The method of claim 6 , further comprising the step of:
employing a spectroscopic instrument to detect said absorption of optical radiation.
8. The method of claim 7 , further comprising the step of employing a passive spectrometer.
9. The method of claim 7 , further comprising the step of employing an imaging hyperspectral FT-IR instrument.
10. The method of claim 7 , further comprising the step of:
employing an optical filtered spectroscopic imaging CCD camera or IR imaging camera that can detect the strong absorption features of triacetone triperoxide.