# Multifunction RF Systems for Naval Platforms
## 4 MFRF System Prototype Development Programs
### InTop  
#### 4.2.1 Overview  
The ONR-sponsored InTop program was initiated in 2009 as a follow-on to AMRFC and is still ongoing. It has the goal of further advancing wideband array and RF component technology for use in MFRF systems, based on modular, scalable, open RF architecture [42; 45]. The main InTop effort involves the demonstration of such technology through the development of five RF system prototypes, each with less MFRF capability than that designed into the AMRFC testbed, but ideally with higher TRL. Given the obstacles to transitioning the more ambitious AMRFC into operation, this was seen to be a more prudent approach that would facilitate spinning off demonstrated core capabilities into acquisition programs, similar to the path followed by the MFEW project. The five prototypes are briefly summarized as follows. A more detailed technical description is provided in subsequent subsections.  
* _MFEW ADM_: The MFEW ADM was largely developed under AMRFC, but was completed under the InTop program. Northrop Grumman was the industry lead on this development. As initially mentioned in Section 4.1.1, the MFEW ADM was based on some of the ES functionality incorporated in the AMRFC testbed. The MFEW technology has subsequently been transitioned to the US Navy's Surface _EW_ Improvement _P_rogram (SEWIP) Block 2 acquisition program [46].
* _EW/IO/Comms ADM_: This ADM supported EA, _i_nformation operations (IO), and _i_ine-of-sight (LOS) terrestrial communications using a common set of AESAs and RF subsystems. Northrop Grumman was the prime contractor for this work, with announced contracts totalling $87 M USD [47]. The ADM has been completed, and the technology has transitioned to the US Navy's SEWIP Block 3 acquisition program.
* _Submarine Wideband SATCOM Antenna Subsystem_: This subsystem involved a set of AESAs that was designed for mounting on a submarine mast to provide the capability for simultaneous SATCOM links in different bands. Lockheed Martin was awarded the development contract worth roughly $32 M USD [48], and has completed the work. The technology is being transferred to the _Advanced_ High-Data-Rate (AdvHDR) submarine SATCOM acquisition project. The work is also applicable to SATCOM for ships.
* _LowRIDR ADM_: The _Low-_band RF Intelligent _D_istribution _R_esource (LowRIDR) ADM aims to consolidate several RF functions that operate in a low frequency band, including communications, EA and ES, into a common set of antennas and related hardware. The ADM is not yet completed.
* _FlexDAR ADM_: The primary RF functions that are included in The _Flexible_ D_istributed _A_rray Radar (FlexDAR) ADM are radar, EA and ES. A missile data link capability is also provided. Raytheon is developing the FlexDAR arrays under contract to ONR [48], including the associated Rx and Tx channels, while NRL is providing the back-end functionality, such as the RAM and signal/data processing. The FlexDAR concept actually comprises two systems that will be network-linked together to also demonstrate the benefits of multistatic radar operation in the form of improved detection, tracking and electronic protection. The ADM is scheduled for completion in the 2018-2019 time frame.