AN/SPN-35
{{Short description|Final approach and landing radar used on naval warships.}}
{{Use mdy dates|date=December 2022}}
{{Infobox radar
| name = AN/SPN-35
| image = SPN-35 Approach Radar LPH-2 Iwo Jima 1987-02-27.jpg
| caption = AN/SPN-35 Approach Radar on LPH-2 Iwo Jima, 1987
| country = United States
| designer =
| manufacturer = ITT-Gilfillan{{cite book |title=Jane's Fighting Ships 1984-85 |last=Moore |first=John Evelyn |publisher=Jane's Information Group |year=1984 |isbn=9780710607959}}{{rp|184|style=ama}}
| introdate =
| number =
| type =
| frequency = 9.0 to 9.2 GHz band
| beamwidth =
| pulsewidth = .2 microseconds{{cite report |last=Maiuzzo |first=M |title=Compatibility Factors Affecting Concept Development of Approach and Landing Guidance System |institution=IIT Research Institute |url=https://apps.dtic.mil/sti/pdfs/AD0707129.pdf}}
| RPM =
| range =
| altitude =
| diameter =
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| azimuth =
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| precision =
| other names =
| related = AN/TPN-8
}}
The AN/SPN-35 is a Precision Approach RADAR (PAR) landing system installed on the Tarawa-class amphibious assault ship and other LHA/LHD-class warships that allows Air Traffic Controllers to provide guidance and glide slope corrections to aircraft during the final approach and landing.{{cite web |title=AN/SPN-35 Aircraft Control Approach Central |url=https://man.fas.org/dod-101/sys/ship/weaps/an-spn-35.htm |last=Pike |first=John |year=1999 |website=Federation of American Scientists}}{{cite news|author1=Capt. Brett Easler |author2=Cmdr. Bruce Herman, USN (Ret.) |title=On Glide Path, On Course: Past, Present and Future |periodical=Naval Aviation News |pages=18–19 |volume=96 |number=3 |year=2014 |access-date=2023-01-02 |url=https://navalaviationnews.navylive.dodlive.mil/Portals/59/Documents/2014_02Summer.pdf?ver=E1-Ary11D2S9xtGs9GuBoA%3D%3D}}
The Joint precision approach and landing system (JPALS) is slated to replace the AN/SPN-35 on U.S. Navy amphibious assault ships.{{cite report |title=Navy Program guide 2011 |author=U.S. Navy |page=43 |year=2011 |url=https://www.hsdl.org/?view&did=713313}}{{cite report |title=Defense Acquisitions: Assessments of Selected Weapon Programs |author=Government Accountability Office |page=81 |url=https://www.gao.gov/assets/files.gao.gov/assets/gao-10-388sp.pdf |date=March 2010}}
Description
The AN/SPN-35 is used to offer guidance to the aircraft pilot on final approach. It provides relative azimuth, range, and elevation information to the radar operator, who relays this as verbal guidance to the aircraft pilot on approach.
The AN/SPN-35A variant has two antennas: the azimuth antenna (AS-1292/TPN-8) and the elevation antenna (AS-1669/SPN-35). The azimuth antenna is located above the azimuth drive assembly on the stabilized yoke. The elevation antenna is mounted on the elevation drive assembly adjacent to the azimuth antenna.{{Cite book |last=Simmons |first=Larry D. |url=https://maritime.org/doc/pdf/et7.pdf |title=Electronics Technician |last2=Ace III |first2=Floyd L. |publisher=NAVAL EDUCATION AND TRAINING PROFESSIONAL DEVELOPMENT AND TECHNOLOGY CENTER |year=1995 |volume=7 |pages=2{{hyphen}}29-2{{hyphen}}30 |access-date=12 Jan 2023 |orig-date=October 1995}}
History
The AN/SPN-35 was developed from the ground-based AN/TPN-8 landing approach control radar.{{Cite book |last=Friedman |first=Norman |title=Naval Radar |publisher=Conway Maritime Press |year=1981 |isbn=0851772382 |location=London}}{{rp|pages=171–172|style=ama}}{{Cite web |title=AN/TPN-18 - Radartutorial |url=https://www.radartutorial.eu/19.kartei/11.ancient/karte096.en.html |access-date=2022-11-19 |website=www.radartutorial.eu |language=en}} It was first evaluated on the {{USS|Kearsarge|CV-33|6}} in 1962, as an AN/TPN-8 mounted to an AN/SPN-6 stable pedestal and secured to an AN/SPN-8 platform. A prototype was evaluated aboard the {{USS|Bon Homme Richard|CV-31}} about a year later as a replacement for the AN/SPN-8 on ASW carriers and small attack carriers.{{rp|pages=171–172|style=ama}} As of 1965, the AN/SPN-35 was being used "primarily on the ASW type carriers."{{Cite journal |journal=Naval Aviation News |date=December 1965 |page=14 |title=For Unerring Performance of Their Duties |last=Fuchs |first=William C}}
The -35A variant was used onboard {{sclass|Nimitz|aircraft carrier}}s prior to 1996, when it was replaced by the AN/SPN-46A/B.{{cite book |title=Nimitz-class aircraft carriers |last=Elward |first=Brad |publisher=Osprey publishing |page=29 |year=2010 |isbn=978-1-84603-759-7}} It remains in use on the {{sclass|Wasp|amphibious assault ship|4}} and {{sclass|America|amphibious assault ship|4}} today.
Platforms
Variants
- AN/SPN-35: Original model that entered service.
- AN/SPN-35A: Improved stabilization system to compensate for pitch and roll of carrier. Replaces the original mechanical-hydraulic stabilization of the original with an electromechanical stabilization system.{{cite book |title=Shipboard Electronic Equipments |author=U.S. Navy |url=https://www.navy-radio.com/manuals/10794c/10794c-12.pdf |year=1969 |id=NAVSHIPS 10794-C |chapter=Chapter 12-Miscellaneous Facilities |pages=213–214}}{{rp|pages=171–172|style=ama}}
- AN/SPN-35B:
- AN/SPN-35C: Upgrade to AN/SPN-35B. Adds Moving Target Detection (MTD), Track While Scan (TWS), and Built-In Test (BIT) capability.{{cite book |url=https://archive.org/details/spn35-a_2001 |year=2001 |title=Navy Training System Plan for the AN/SPN-35C Aircraft Control Approach Central |author=U.S. Navy |page=1}}
See also
{{Portal|Electronics}}
- AN/SPN-46(V)1
- {{anl|Joint Electronics Type Designation System}}
- List of radars
- List of military electronics of the United States
References
{{reflist}}
External links
- {{HathiTrust |htid=uiug.30112105099490 |title=Approach, vol. 9}} {{hyphen}} Refer to page 7 of Sept. 1963 issue for discussion of impact for SPN-35 relative to what came before.