USWTR Inc II III RFP Questions.xlsx

Sheet1

Deep Receive Requirement

The minimum acoustic shallow water receive requirement levels listed in Table 2 (16 dB minimum) are lower than the deep water levels. Since shallow water nodes operate in a noisier environment than deep water nodes did the government intend the shallow water node receive level be consistent with USWTR-EC at approximately 30 dB?

Also, the 16 dB re uPa^2/Hz level listed for 40 kHz is below the thermal noise limit (17 dB) for an omni transducer, and one having 100% efficiency. We suggest using the existing USWTR Increment 1 noise specification for shallow water to maintain commonality with the USWTR Increment 1 shallow water Preamp design and maintain an as-installed high MRL. The existing, high MRL, USWTR Increment 1 Preamp circuit and the subsequent signal conditioning circuit were tailored to address the Increment 1 noise and maximum signal levels and are different than the circuits tailored for deep water.

Does this "ten unique signals" refer only to the (now) ten Mappable Analog Inputs from which to select a projector signal? 10 Simultaneous, and continuous projectors requires an increase in continuous JBox current so that it is available for projectors. This increases the required power dissipation in the JBox by over 33%, and the change results in a lower MRL JBox design.

The note below has application to multiple performance and test requirements.

Note 1: If the high number of active projectors is to support multiple projector sources for Self Track projections, can the duty cycle of each projector be limited to the self track burst signal duty cycle? This means the projector would "idle" with no modulating signal for the majority of the duty cycle (i.e. no repeated power amplifier activation). This would reduce the requirement for continuous high power current to a much smaller level that supports 10 low duty cycle projections, and will allow the existing, high MRL power amplifier design to accommodate one projector on each string with no upper limit if the short bursts were arranged to avoid more than a small number of simultaneous projections. We suggest requiring at least 2 simultaneous burst projections with the goal to define the highest limit.

The stated beam pattern limits are identical to the Increment 1 USWTR-EC. However, for this solicitation they apply to a higher frequency range: up to 4.2kHz (from 3.1 kHz). Is it intended that the same vertical beam pattern limits apply over this new, wider bandwidth? The extended frequency band LB projector, including this beam pattern requirement, drives to a low MRL solution.

Deep: 3.3.2.2.2 Shallow: 3.3.2.9.2 Each LF transducer shall generate a maximum SPL of at least +190 dB//uPa at 1 meter at 2.5 kHz.

Should this be 186 dB re 1 uPa @ 1 m, as was the case on USWTR Increment 1.? ("Each LB transducer shall generate a maximum SPL of at least +186 dB/μPa at 1 meter at 2.5 KHz."). The electrical power required to drive the LF Projector to 190 dB requires a 0.5 ohm cable resistance, and this manufacturer's cable does not meet the referenced Telecom Cable specification. Also - the 190 dB re 1uPa does not agree with NUWC's requirements set for the related UTIC-supported wideband projector development effort.

This duty cycle test is at odds with the performance requirements in Section 3.3.2.2.7 (Deep) and 3.3.2.9.6 (Shallow), where it is stated "Each LF transducer shall operate at a 50% duty cycle for 10 periods of 100 seconds per period without damage at maximum output level." This test requirement drives to a low MRL solution. We recommend making the duty cycle performance and test requirements the same.

Also: Please see Note 1, above, suggesting revised Transmit Duty Cycle requirements.

This duty cycle test requirement is at odds with the performance requirement in Section 3.3.2.9.6 (Shallow) [and 3.3.2.2.7 (Deep)] where it is stated as 50%. This test requirement drives to a low MRL solution. We recommend making the duty cycle performance and test requirements the same.

Please provide a mapping from the SOW GFI numbers to actual GFI filenames & sectiosn so that we can make sure we have a complete set of GFI.

Question: Are there 2 additional CDRs, and if so, what do they cover?

Question: Is it possible to schedule a separate CDR for the HF and LF projectors to include manufacturer’s test results as well as results from the Government’s APTF and Dodge Pond acoustic test facilities?

The Telecom Cable specification (GFI #6.1.38) applies to all range internode cables (both deep and shallow), but only to the SOAR Trunk Cable (SOW 4.42 invokes GFI #6.1.38 on both the Trunk and Internode). Did the government intend to invoke GFI #6.1.38 to only the SOAR Trunk cable? Was it intended that the trunk cable for SOAR be different?

In the provided GFI #6.1.38, Commercial Undersea Telecommunications Cable Minimum Requirements/Specifications.pdf, Table 1 lists ITU-T Recommendation G.655 as the required fiber type. OFS Allwave fiber provides superior performance to the required fiber due to its ‘suppressed water peak’, which provides better optical loss characteristics at relevant wavelengths. Is it allowable to use ‘Suppressed water peak’ optical fiber, such as OFS Allwave, which is built IAW ITU-T Recommendation G.652?

In the provided Commercial Undersea Telecommunications Cable Minimum specifications.pdf, Section 3.0 it is required that “the undersea telecommunications cable shall include an optical fiber transmission path from end to end with a quantity of > 12 fibers”. Given there are 14 pigtails at each JBox, 12 fibers in the internode cables and JBox pigtails will total 168, which greatly outnumbers fibers available in the Trunk. It leads to a more costly implementation if the fibers are present in the cable but not used. Is it allowable to use less than 12 fibers in the internode and pigtail cables?

The instructions for completing table CE-1 state that “Only contract references designated in Table ES-2 (Relevant Contract Summary) shall be used in completing this Volume…”, and “….the contracts identified as P1, S1, T1 etc. in Table ES-2 shall be the same P1, S1, T1, etc. contracts identified in Table CE-1”.

We cannot locate a Table ES-2 in the provided RFP materials. We do note that Table CA-3 Summary of Contract References identifies the contracts numbering method P1, S1, T1.

The instructions state that the item should reference the same contract as identified in Table PP-1.

We cannot locate a Table PP-1 in the provided RFP materials.

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