Sense and inject moving target indicator apparatus

• US 4,219,845 A
• Filed: 04/12/1979
• Issued: 08/26/1980
• Est. Priority Date: 04/12/1979
• Status: Expired due to Term

• Current Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Gibbons, Martin D., Aldrich, Richard W.
• Primary Examiner(s): Richardson, Robert L.
• Assistant Examiner(s): Orsino, Jr., Joseph A.
• Application Number:
  US06/029,585
• Time in Patent Office: 502 Days
• Field of Search: 358/105, 358/212, 358/213, 357/24, 250/211 J
• US Class Current: 348/155
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors

Abstract

A moving target indicator apparatus utilizing charge injector device (CID) sensors to detect the presence or absence of a moving target. A signal from a possible target site in the sensor array is measured during a flow scan and is processed with the signal return from a second scan to determine absence or presence and direction.

Claims

1. A sense and inject moving target indicator apparatus comprising in combination:

means for injecting a charge, said charge injecting means having a set reference line and a plurality of set lines, said set reference line having a predetermined charge level thereon, said charge level being variable, each of said plurality of set lines having a controllable, progressively smaller charge level thereon, said set reference line charge level being larger than the charge levels available to each of said plurality of set lines, each of said plurality of set lines being individually selectable, each of said plurality of set lines being connected in common to an output line,

a CID array having a plurality of sensor rows therein, one of said plurality of sensor rows being designated a reference row, any one of the remaining rows of said plurality of sensor rows being designated a selected row, each of said plurality of sensor rows being individually selectable, said reference row being connected to said set reference line, said remaining rows of said plurality of sensor rows being connected in common to said output line, and,

a charge sensing means having a first and second input line, said first input line being connected to said reference row and said reference set line, said second input line being connected to said common line, said charge sensing means differentially sensing the charge applied to said first and second input line, said charge injecting means injecting a reference charge into said reference row, said CID array being charged by a light flash, said charge injecting means injecting said selected row with a first charge, said first charge having a greater level than said reference charge, said charge sensing means differentially reading out the charge in said reference row and selected row, said charge sensing means providing a differential voltage in response to said differential read out, said charge sensing means multiplying said differential voltage signal by a gain factor to provide a correction signal, said correction signal being applied to said charge injecting means, said charge injecting means applying said correction signal to said selected row, said charge sensing means differentially reading out said reference row and selected row to yield a first field signal, said first field signal providing the response to whether or not a moving target indication is present.

2. A sense and inject moving target indicator apparatus as described in claim 1 further including a second correction signal being provided by said charge sensing means, said charge sensing means thus providing a double charge correction.

3. A sense and inject moving target indicator apparatus as described in claim 1 wherein said plurality of set lines equals three.

4. A sense and inject moving target indicator apparatus as described in claim 1 wherein said charge in said reference line is determined by V₁ -Vo₁ where V₁ is the injection voltage applied to the array elements and Vo is chosen such that any reference line site will contain less bias charge than any array site and V₁ and V_o are both negative in P-channel devices.

5. A sense and inject moving target indicator apparatus as described in claim 2 wherein a second field is generated, said second field being integrated in said CID array, said CID array then being readout to provide a moving target indication.