FOR SYSTEMS THAT ROLL ABOUT THE VEHICLE LONGITUDINAL AXIS

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04558A001800110031-7
• Release Decision: RIPPUB
• Original Classification: T
• Document Page Count: 3
• Document Creation Date: December 28, 2016
• Sequence Number: 31
• Content Type: CABLE

Approved For Release 2008/02/29: CIA-RDP78BO4558AO01800110031-7
T 0 P S E C R E T 2 002392
to FOREMOST REQUIREMENT:
A, FOR SYSTEMS THAT ROLL ABOUT THE VEHICLE LONGITUDINAL AXIS,
DISASSOCIATE THE S/I PACKAGE FROM THE ROLLING MAIN CAMERA SYSTEM SO
IT DOES NOT ROLL. THEN THE OPTICAL AXIS OF THE STELLAR CAMERA
SHOULD POINT AT ORBITAL POLE AND INDEX CAMERA TO NADIR REGARDLESS
OF PROGRAMMED ROLL APPLIED TO MAIN CAMERA.
B. IF IT IS IMPOSSIBLE TO PLACE THE S/I PACKAGE SUCH THAT
IT DOES NOT ROLL WITH THE MAIN CAMERA SYSTEM, THEN INCREASE THE
LOCK ANGLE OF THE S/I UNIT ENOUGH TO ENSURE CLEAR STELLAR VIEW
WHEN MAIN CAMERA SYSTEM IS IN MAXIMUM DESIGNED ROLL POSITION.
C. CONDITION A. IS MUCH PREFERRED OVER CONDITION B. HOWEVER,
IN EITHER CASE IT IS NECESSARY TO KNOW THE CALIBRATED ANGULAR
RELATIONSHIP BETWEEN THE S/I SYSTEM AND MAIN CAMERA SYSTEM. A
DETERMINATION OF THESE ANGLES SHOULD BE MADE WITH BOTH SYSTEMS IN
NOMINAL VERTICAL POSITIONS. PERHAPS BOTH SYSTEMS CAN BE MECHANICALLY
TIED TOGETHER BUT STILL PERMITTING REQUIREMENTS STATED IN PARAGRAPH
IA OR IB TO BE SATISFIED.
2. ASIDE FROM LOCK ANGLE, FOLLOWING IS PARTIAL LIST OF WHAT
WOULD BE DESIREABLE IN FUTURE S/I SYSTEM.
A. STELLAR CAMERA
Declassification Review by NGA/DoD
TOP SECREI
GIi01!P 1
Excluded from autamaM
downgrading aid
declasaific:tion
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(1) CONE ANGLE OF NOT LESS THAN 28 TO 30 DEGREES
(2) FOCAL LENGTH NOT GREATER THAN 3 IN. DEPENDING ON
CONE ANGLE SELECTED
(3) ROUND FORMAT
(4) FIDUCIAL MARKS
(5) SHRINKAGE REFERENCE MARKS (RESEAU)
(6) COMPLETELY BLACKENED THROUGHOUT, INCLUDING LENS MOUNT
AND INTERIOR OF CAMERA
C7) ADEQUATELY BAFFLED SO THAT EARTH FLARE IS ELIMINATED
(8) SEPARATE FILM FEED
(9) BETWEEN THE LENS SHUTTER
(10) BINARY TINE C29 BITS) ON EACH EXPOSURE
(11) COMPLETE CALIBRATION OF THE ORIENTATION BETWEEN STELLAR
AND INDEX CAMERAS
(12) CALIBRATION OF PRINCIPAL POINT, FOCAL LENGTH, AND
LENS DISTORTION
(13) PROVISION FOR 1/4 TO 4 SECONDS EXPOSURE TINE. SPEED
OF FILM EITHER TO BE COMMENSURATE TO THE AMOUNT OF
RADIATION IN ENVIRONMENT, OR FILM PATH TO BE SHIELDED
TO PERMIT THE USE OF FASTER FILMS.
(14) CYCLE TINE: TWO TO FIVE SECONDS
(15) OPERATION INDEPENDENT OF ANY OTHER CAMERA
B. INDEX CAMERA
C1) 3 TO 6 IN. FL WITH CONE ANGLE GREATER THAN 45 DEGREES.
FL AND FORMAT SIZE TO DEPEND ON WEIGHT LIMITATIONS.
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IF WEIGHT IS NO PROBLEM 6 IN. FL PREFERRED. FL SHOULD
NOT BE LESS THAN 3 IN. LENS SHOULD HAVE HIGH RESOLVING
POWER.
(2) FIDUCIAL MARKS
(3) SHRINKAGE REFERENCE MARKS (RESEAU)
(4) CALIBRATION FOR POSITION OF PRINCIAPL POINT, FOCAL
LENGTH AND LENS DISTORTION
(5) SEPARATE FILM FEED
(6) BETWEEN THE LENS SHUTTER
(7) BINARY TIME (29 BITS) ON EACH EXPOSURE
(8) OPERATION INDEPENDENT OF ANY OTHER CAMERA
(9) SQUARE FORMAT
(10) BLACKENED AND BAFFLED THROUGHOUT
(11) CYCLE TIME TO ASSURE 60.65 PERCENT OVERLAP
(12) SHUTTER SPEED RANGE AS DICTATED BY PAST EXPERIENCE
GAINED WITH CORONA MISSIONS.
3. INCORPORATE "END OF PASS MARKER" FOR BOTH S AND I CAMERAS.
T 0 P S E C R E T
Approved For Release 2008/02/29: CIA-RDP78B04558A001800110031-7