Editing Lockheed SR-71 Blackbird (section)

===Sensors and payloads===
[[File:SR-71 Defensive System B.jpg|thumb|The SR-71 Defensive System B]]

The SR-71 originally included optical/[[Thermographic camera|infrared imagery]] systems; [[side-looking airborne radar]] (SLAR);<ref>{{cite web |title=SR-71 Online – SR-71 Flight Manual: Section 4 |url=https://www.sr-71.org/blackbird/manual/4/4-86.php |website=Sr-71.org |pages=4–86}}</ref> [[electronic intelligence]] (ELINT) gathering systems;<ref>{{cite web |title=SR-71 Online – SR-71 Flight Manual: Section 4 |url=https://www.sr-71.org/blackbird/manual/4/4-99.php |website=Sr-71.org |pages=4–99}}</ref> defensive systems for countering missile and airborne fighters;<ref>{{cite web |title=SR-71 Online – SR-71 Flight Manual: Section 4 |url=https://www.sr-71.org/blackbird/manual/4/4-123.php |website=Sr-71.org |pages=4–123}}</ref><ref>{{cite web |title=SR-71 Online – SR-71 Flight Manual: Section 4 |url=https://www.sr-71.org/blackbird/manual/4/4-129.php |website=Sr-71.org |pages=4–129}}</ref><ref>{{cite web |title=SR-71 Online - SR-71 Flight Manual: Section 4 |url=https://www.sr-71.org/blackbird/manual/4/4-132.php |website=Sr-71.org |pages=4–132}}</ref><ref>{{cite web |title=SR-71 Online - SR-71 Flight Manual: Section 4 |url=https://www.sr-71.org/blackbird/manual/4/4-146.php |website=Sr-71.org |pages=4–146}}</ref> and recorders for SLAR, ELINT, and maintenance data. The SR-71 carried a [[Fairchild Camera and Instrument|Fairchild]] tracking camera and an [[Thermographic camera|infrared camera]],<ref>{{cite book |url=https://www.cia.gov/library/center-for-the-study-of-intelligence/csi-publications/books-and-monographs/a-12/Archangel-2ndEdition-2Feb12.pdf |archive-url=https://web.archive.org/web/20120926211605/https://www.cia.gov/library/center-for-the-study-of-intelligence/csi-publications/books-and-monographs/a-12/Archangel-2ndEdition-2Feb12.pdf |url-status=dead |archive-date=26 September 2012 |title=Archangel: CIA's Supersonic A-12 Reconnaissance Aircraft |edition=2nd |first=David |last=Robarge |publisher=CSI Publications |date=January 2012 |access-date=19 March 2019}}</ref> both of which ran during the entire mission.

As the SR-71 had a second cockpit behind the pilot for the RSO, it could not carry the A-12's principal sensor, a single large-focal-length optical camera that sat in the "Q-Bay" behind the A-12's single cockpit. Instead, the SR-71's camera systems could be located either in the fuselage chines or the removable nose/chine section. Wide-area imaging was provided by two of [[Itek]]'s [[Operational Objective Camera]]s, which provided stereo imagery across the width of the flight track, or an [[KA-80 Optical Bar Camera|Itek Optical Bar Camera]], which gave continuous horizon-to-horizon coverage. A closer view of the target area was given by the [[HYCON Technical Objective Camera]] (TEOC), which could be directed up to 45° left or right of the centerline.<ref name="auto">{{harvp|Crickmore|1997|p=74}}</ref> Initially, the TEOCs could not match the resolution of the A-12's larger camera, but rapid improvements in both the camera and film improved this performance.<ref name="auto"/><ref>{{harvp|Crickmore|1997|p=563}}</ref>

SLAR, built by [[Goodyear Aerospace]], could be carried in the removable nose. In later life, the radar was replaced by Loral's Advanced [[Synthetic Aperture Radar]] System (ASARS-1). Both the first SLAR and ASARS-1 were ground-mapping imaging systems, collecting data either in fixed swaths left or right of centerline or from a spot location for higher resolution.<ref name="auto"/> ELINT-gathering systems, called the Electro Magnetic Reconnaissance System, built by AIL could be carried in the chine bays to analyze electronic signal fields being passed through, and were programmed to identify items of interest.<ref name="auto"/><ref>{{harvp|Crickmore|1997|p=77}}</ref>

Over its operational life, the Blackbird carried various [[electronic countermeasures]] (ECMs), including warning and active electronic systems built by several ECM companies and called Systems A, A2, A2C, B, C, C2, E, G, H, and M. On a given mission, an aircraft carried several of these frequency/purpose payloads to meet the expected threats. Major Jerry Crew, an RSO, told ''[[Air & Space/Smithsonian]]'' that he used a [[Radar jamming and deception|jammer]] to try to confuse [[surface-to-air missile]] sites as their crews tracked his airplane, but once his threat-warning receiver told him a missile had been launched, he switched off the jammer to prevent the missile from homing in on its signal.<ref>{{cite journal|url=http://www.airspacemag.com/flight-today/blackbird-diaries-180953373/ |title=Blackbird Diaries {{!}} Flight Today |journal=Air & Space Magazine |page=45 |date=December 2014 |access-date=24 July 2015}}</ref> After landing, information from the SLAR, ELINT gathering systems, and the maintenance data recorder were subjected to postflight ground analysis. In the later years of its operational life, a datalink system could send ASARS-1 and ELINT data from about {{convert|2000|nmi|km|abbr=on}} of track coverage to a suitably equipped ground station.{{Citation needed|date=February 2012}}