LTI 20-20 Marksman
Laser Technology, Inc.

IACP approved

Note: European version has a different speed measuring range and different minimum and maximum operating distance.

OPERATION

• single-unit hand-held system
  optional shoulder mount
  supply voltage -- car battery (optional portable battery pack)
• scope sight
  -- optically filtered, no magnification, red highlighting dot to mark target
  -- optional 2x magnification and in-scope speed display
  -- operator alignment/adjustment (test target at least 100 yards)
  -- internal battery
• Instant On
• stationary operation only
• measures speed for on-coming and going traffic
  measures range of stationary objects
• Target (moving) Acquisition Time: 0.3 sec minimum
  (longer time required for slower targets)
• Beamwidth:
  3 mrad -- late 1990's models
  3.5 mrad -- early 1990's models
• timing mode
  Operator measures (with ladar) distance between objects (stores distance in ladar memory), and pushes a button when a target passes each object (ladar calculates time between button pushes); ladar computes target speed from distance (known) divided by time (button pushes). Ladar does not transmit to calculate speed in this mode.

CONTROLS

• Transmit / Lock display
  beeps when target speed calculated (1/3 second)
  TRIGGER pressed -- transmitting
  TRIGGER released -- display locked
  speeds remains on display until next transmission
• Speed / Range mode
• Timing Mode
• Test
  -- light test
  -- self-test (some portion of digital circuits)
• Scope Brightness (on scope)
• Display Intensity knob
• On/Off

DISPLAYS / INDICATORS

• Display (LEDs)

  Target Speed
  0 to 200 mph (0 to 320 kmh)
  plus (+) for approaching, minus (-) for receding targets
  accuracy: +/- 1 mph
  or
  Target Range
  30 to 3,500 feet (9 to 1067 meters) -- late 1990's models.
  30 to 1,000-2,000 feet (9 to 300-600 meters) -- early 1990's models.
  accuracy: +/- 6 inches

  ERROR MESSAGES
  not all versions have all error messages

  Measurement error
  E01 -- target never acquired. The target was out of range or was too close.
  E02 -- insufficient data. The instrument's view was obstructed or the target moved out of range.
  E03 -- unstable targeting. Caused by poor aiming or by panning off the target
  E07 -- optical interference detected. Indicates the possible use of a laser jamming device. Accompanied by a warble tone.

  Timing error
  E04 -- the instrument did not have enough time to determine the speed. Minimum time is 1 second.
  E05 -- the instrument had too much time to determine the speed. The maximum time is 99.99 seconds
  

  System error
  E50, 51, 54 -- self-calibration failure. The instrument detected a problem during self calibration. Contact manufacturer.
  E52, 53 -- temperature failure. The instrument is being operated outside its recommended operating temperature range.
  E60, 61, 62, 63 -- memory failure. The instrument's electronucs may have been tampered with. Contact manufacturer.
  E70 -- key activated. A function key was pressed during power-up sequence. Power off, then on again.

  other errors
  do -- Display overflow. The number to be displayed exceeds the display capacity.
  lo b -- Low battery. The Instrument's supply voltage level is insufficient.

  EUROPEAN VERSION
  TARGET SPEED
  0 to 155 mph (0 to 250 kmh)
  accuracy: +/- 1 mph up to 60 mph, 3 percent over 60 mph
  TARGET RANGE (stationary target)
  65 to 1,300 feet (20 to 400 meters)
  

• Speaker -- beeps when target speed calculated (1/3 second)

SPECIFICATIONS

The unit is programmable, some specifications and features, such as speed/range in English or metric units (mph/ft or kmh/m) are a function of software version installed.

Manufacturer claims unit processes a target if more than 75 percent (45 out of 60 pulses for US version) of target echoes during one sample period (0.3 second) are valid. Valid echoes must be within 20 centimeters (about 8 inches) of expected range (about 1.3 nanoseconds).

       speed range   +/-200 mph (on-coming and going traffic)
    speed accuracy   +/-1 mph velocity
       sample time   0.3 seconds

      target range   30 feet (min) to 1,000 or 2,000 feet
    range accuracy   +/- 0.5 feet (6 in) range (claimed)
                 
         beamwidth   3.5 mrad (0.2 degrees)
      early models   3 mrad (0.172 degrees)

          aperture   separate transmit / receive
                     transmit above receive aperture

        wavelength   approx 904 nm
   pulse rise/fall   less than 1 ns
      light source   3 diodes lined up side-by-side

     environmental   -22 to 140 degrees Fahrenheit
                     (-30 to 60 degrees Celsius)

        dimensions   3.5 x 5 x 8 inches
            weight   4.5 lb

       Data Output   serial data for still or video camera

      LASER PULSES   reported (best guess)
                     60 pulses per sample time
                     200 pulses per second (sample time 300 ms)

                     125 pulses per second (European version)

       pulse width   12 ns pulse width