Advanced Systems Integration Lab (ASIL),
Naval Air Warfare Center
Aircraft Division, Patuxent River MD

  but to appreciate the size...come back

The Advanced Systems Integration Lab (ASIL) is located at the Naval Air Warfare Center Aircraft Division, Patuxent River, Maryland. ASIL is a quiet, isolated, flexible test facility that accommodates sensor testing for Electronic Warfare, Communications/Navigation, and a wide range of other electronic systems. The photo above shows a P-8 Poseidon maritime patrol/ surveillance aircraft comfortably fitting inside the ASIL chamber. What looks like the right wall of the chamber is in fact the chamber door--at 200 feet wide and 80 high, it is the largest single-leaf RF shielded door ever built.

The Howland Company led the concept design study. We wrote the construction spec sections for the RF shield, shield testing, anechoic material installation, and VSWR testing of the installed absorber; we assisted in development of the spec sections for the RF shielded hangar door and ceiling hoists; and we prepred drawing details for shielding and anechoic construction. During construction, we managed the general contractor's shielding and anechoic QA/QC programs--we reviewed and approved installation procedures and test plans & procedures, monitored all testing, and reviewed test reports.

ASIL-Modular RF Absorber Panels: installing the absorber panels on a grid framework well inside the welded steel RF shield allows positioning of test antennas and sensors at virtually any place in the chamber with minimal exposed cabling or mounting hardware.
ATEC Industries installers securing the modular RF absorber wall panels; the RF shield is visible on the left, behind the RF absorber framing.
ASIL's two 40-ton hoists are installed on bridge cranes above the anechoic material ceiling; this allows positioning of two aircraft in the chamber at the same time, with greater flexibility in spacing and orientation.
Monitoring load capacity testing of one of the chamber's two 40-ton bridge crane hoists.
ASIL-RF absorber testing--The Howland Company monitored all shielding and anechoic performance testing and reviewed test plans, procedures, and reports before their submittal to the Navy.
Ray Howland (right) monitoring final VSWR testing of the installed RF absorber panels.

The RAM tip-to-tip dimensions of the ASIL anechoic chamber are 180 ft x 180 ft x 60 ft. (55m x 55m x 18m). The chamber is large enough to accommodate large systems such as the Space Shuttle and aircraft as large as a C-17. Offices and lab space needed to generate the required electromagnetic environment and analyze test results surround the chamber.

Two 40-ton bridge cranes are available for test article support. The chamber floor is designed for even heavier loads. A large test article preparation area is provided between the single-leaf 80 ft x 200 ft shielded anechoic door and the facility's outer hangar doors.

The shielding effectiveness of the chamber has been publicly described to be at least 110 dB from 30 MHz to "over 18 GHz." The return loss of the installed RAM is frequency dependent, but typically over 50 dB.


An MQ-4C Triton is lifted inside Patuxent River's anechoic chamber Aug.12  for electromagnetic compatibility (EMC) testing. Northrop Grumman MQ-4C Triton UAS, centerpiece of the Navy's Broad Area Maritime Surveillance (BAMS) mission, inside the chamber. Specialized lifting gear by Caldwell made from composite material allows safe handling of the aircraft with minimal impact on RF measurements. -- US Navy photo

EF-18G Growler electronic attack & jamming systems were validated in the ASIL chamber.
Test set-up made much more efficient with use of walkway panels that can be added to any of the chambers modular floor absorber pallets.
Advanced System Integration Lab, NAWC Patuxent River
  US Navy photos

All RAM is mounted on removable panels to facilitate reconfiguration as required for specific tests. Throughout the entire chamber, the RAM support structure is at least 6 feet inside the chamber's shielded walls and ceiling. This design, together with the removable RAM panel system, permits openings to be made at any point in the RAM -- without penetrating the shield. Full access to all points throughout the chamber means that the unique requirements of a specific test determine emitter and sensor placement. The alternative, found in other large chambers--designing test scenarios around the limitations of the chamber layout--allows far less flexibility and efficiency.

Fourteen foot high basement tunnels, also inside the shield envelope, provide space to locate equipment and cabling for access to any area of the chamber floor. Fiberglass walk-on platforms for use during test preparation may be positioned on top of any of the floor RAM pallets.

Access panels through the RF shield permit connection to test and simulation systems installed in lab spaces outside the shield envelope. These systems include the Joint Communications Stimulator (JCS), Generic Radar Target Generator (GRTG), and the Infrared Scene Simulator (IRSS). Aircraft air and hydraulic supplies are also provided.


Advanced Systems Integration Facility among other NAVAIR facilities at NAS Patuxent River
 US Navy photos

This Navy photo of one of the first F-35C aircraft to arrive at Pax River for testing shows ASIL in the heart of NAVAIR's east
coast test complex; to the left of the ASIL is the shielded hangar housing the Aircraft Anechoic Test Facility. Behind and to the right
of ASIL is the water tank for ASIL's fire suppression system, and the 'wall' on the right side of the building is the pocket for
the single-leaf, 100dB RF shielded anechoic chamber door.


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