DOD CODE MATRIX BLOCK

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04747A001600010068-0
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 3
• Document Creation Date: December 28, 2016
• Document Release Date: March 1, 2000
• Sequence Number: 68
• Publication Date: April 27, 1965
• Content Type: MF

Approved For Rpjese 2001/08/ E f [TP78B04747A 0 600010068-0
IPD/NPIC-10)+-65
27 April 1965
MEMORANDUM FOR: Assistant for Plans and Development, NPIC
ATTENTION: Plans Branch
SUBJECT: DOD Code Matrix Block
REFERENCE: NPIC/P&DS-l20/65 dated, 25 March 1965
1. There appears to be some confusion as to what steps are
involved in the collection, recording, transcription, and utilization
of frame-specific data in various photo-reconnaissance and exploitation
sys-cems. Since our response to the question posed in the referenced
,memorandum is based on our understanding of these steps we propose to
briefly outline the process. This outline will serve. as a common base
.f understanding for subsequent intercourse between our respective
organizations.
2. The DOD data block can be described or characterized at sev-
era. different levels:
a. Bit-format specification. In this sense the DOD
data block is described as being a certain number of binary
point symbols arranged in a certain pattern on the film.
b. Code specification. This states the manner in which
the bits in the matrix are grouped together in n-bit groups
and the manner in which the elements of some m-element
(2n Za.m ?2) symbol set (Arabic numerals, Roman alphabet, or
the union of these two sets) are mapped into the 2n possible
n-bit strings (i.e. the encoding to be used).
c. Field description. This gives us the assignment of
names to groupings of (encoded) symbols. (For a hypothetical
example - vehicle speed to be given in the 6th through 10th
symbol positions to lOths of a knot.)
3. We now turn to the steps that are involved in using the data
recorded on a frame of reconnaissance photography "using the DOD Data
Block". We can recognize at least these separate operations that would
hold in a large scale exploitation effort.
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IPD/NPIC-l04-65
a. The bit pattern recorded on. each frame must be
transcribed into a computer-readable media (such as punched
cards or magnetic tape) along with, some unique identification
of the frame to which the data pertains. If subsequent pro-
cessing is to be done with a binary computer the transcrip-
tion can be a one-to-one mapping into the bits of a string of
binary computer words. The timely and accurate accomplish-
ment of this transcription task is basic to any automated
system to use the data recorded on the film. A contract is
now being let to - by the Development Branch of your
organization for the production of a "data block reader" that
will accomplish this function for several different formats.
In particular, it will do this for the bit pattern specified
for the DOD data block.
b. The next phase of the exploitation process consists
of the translation of the bit patterns into symbols of the
higher level language. Assuming an encoding that is well-
defined in advance (for example, XS-3 code) this translation
logic can be wired into the "reading" hardware. An alterna-
tive approach (and a more practical one if several different
codes are to be used) is to perform this translation as a
trivial programmed function in the first computer program
that accesses the data.
c. The third and subsequent steps in this chain are
those that now pluck out the values from their respective
fields and use these values in some manner in the various
parametrically expressed mathematical models that are used as
the computational frameworks for the exploitation process.
The steps that we have just lumped together as (c) are completely
dependent on the camera systems that were employed in collecting the
photography. That is,.the mathematical models reflect the camera sys-
tem rather than the manner in which the data pertaining to the camera
system is recorded. It is to these mathematical models that the great
bulk of our photo-metrical programming effort is directed. The pro-
gramming involved in decoding the bit patterns is, as previously
remarked, trivial and would scarcely be undertaken as an independent
project in advance of some requirement to incorporate a specific camera
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"reader" outpu with the input requiremento s) Of our present andbsubse-
quent computers.
!? If you are witting of any plans to supply photographic inputs
to this Center from reconnaissance systems using the DOD data block and
if these plans are of such nature as to warrant our providing photo-
metrical and photo-coverage plotting capability to the Center we would
ask that you forward such requirement to use
system (that uses the DOD data block) into the set for which we provide
metrical data reduction services. With regard to the process of trans-
cribing the bit patterns into corn uter- eadable media, we have been
working with
Chief, Information Processing Division
NPIC
Distribution:
O&l - Asst/P&DS: Att
1 - P&DS/DB: Attn:
1 - Asst/PAG
1 - Ch/PID
1 - Ch/TID
2 - Ch/IPD
Approved For Release 2001 -RDP78BO4747AO01600010068-0