SPECIAL NOTICE
59 -- RFI TDW Transmitter Drive Waveform/s
- Notice Date
- 1/31/2006
- Notice Type
- Special Notice
- NAICS
- 335999
— All Other Miscellaneous Electrical Equipment and Component Manufacturing
- Contracting Office
- DHS - Direct Reports, United States Coast Guard (USCG), Commanding Officer (fcp), U.S. Coast Guard Training Center Cape May, Administration Building Room 212A, Cape May, NJ, 08204-5092
- ZIP Code
- 08204-5092
- Solicitation Number
- Reference-Number-21-06-TDW-Lown
- Response Due
- 2/20/2006
- Archive Date
- 3/7/2006
- Description
- REQUEST FOR INFORMATION PURSUANT TO FAR 15.201(e) INTRODUCTION The U. S. Coast Guard is developing requirements for a LORAN-C signal generation and control system to be used as a component of LORAN-C transmitter system. The purpose of this Request for Information (RFI) is to gather information to assist the U. S. Coast Guard in formulating functional requirements, and identify qualified vendors who are able to meet our requirements. The U. S. Coast Guard is open to alternative ideas. Respondents are encouraged to provide information about alternatives that can help the U. S. Coast Guard better define its requirements and obtain a solution that meets its needs. BACKGROUND LORAN-C was originally developed to provide radio navigation service for U.S. coastal waters and was later expanded to include complete coverage of the continental U.S. as well as most of Alaska. Twenty-four LORAN-C stations work in partnership with Canadian and Russian stations to provide coverage in Canadian waters and in the Bering Sea. LORAN-C provides better than 0.25 nautical mile absolute accuracy for suitably equipped users within the published user areas. Advances in technology have allowed for greater automation and consolidation of LORAN-C operations. The existing system is being modernized to take advantage of such technology. More information on system modernization may be found at http://www.navcen.uscg.gov/loran/modernization.htm . THE OPERATING STATUS OF LORAN-C LORAN-C provides position, navigation, and timing (PNT) services for both civil and military air, land and marine users. LORAN-C is approved as an en route supplemental flight navigation system for both Instrument Flight Rule (IFR) and Visual Flight Rule (VFR) operations. The LORAN-C system serves the 48 continental states, their coastal areas, and Alaska. While the U. S. Government continues to evaluate the long-term need for the LORAN-C radio navigation system, it will continue to operate the LORAN-C system in the near term. PURPOSE OF REQUEST FOR INFORMATION The U.S Government is exploring methods of generating and controlling a transmitter drive waveform(s) (TDW) for current LORAN-C non-linear transmitters as well as for controlling possible future expeditionary (portable) linear LORAN-C transmitter/amplifiers. The system will be required to develop a TDW that will result in the transmission of the ideal LORAN-C pulse at the antenna feed point. The system must be capable of sampling the resultant pulse(s) and making automated adjustments to the TDW to compensate for variations in the transmission path. Though the system shall be capable of running in a fully automated mode, the system should allow operators to make adjustments that would result in changes in the transmitted pulse(s). At the heart of the LORAN-C system is very precise and highly accurate LORAN-C Timing and Frequency Equipment (TFE). This system shall be utilized for all reference frequencies and timing triggers for the waveform generation and control system. Signals that will be made available for use in the TDW generator and control system are attached. Additionally, the U. S. Coast Guard adopted the testing of different modulation techniques to further enhance the LORAN-C system, establishing a test program for the enhancement of the LORAN-C signal pertaining to availability, accuracy, integrity, and continuity. The proposed modulation scheme for this enhanced LORAN-C system is known as 9th Pulse Modulation, and it may be reviewed at http://www.navcen.uscg.gov/loran/9th-pulse-modulation-ldc.html . Voluntary submissions for differing modulation techniques to enhance the Loran signal are welcomed. Test programs to enhance the capability of LORAN-C were established to allow for the following: Note: Please note that the information presented in this section is pre-decisional and not fully detailed. ?X Additional Communications over the Loran Signal: Methods of using the LORAN-C signal to broadcast information to enhance system accuracy and integrity. ?X Differential Loran: The concept of differential Loran is being revisited to improve accuracy for both navigation and timing users. ?X Early Sky wave: The effects of early sky waves on the integrity of LORAN-C in the Continental U. S. ?X Time of Transmission (TOT) Control: Moving to TOT control would enable chain timing synchronization. The purpose of this Request for Information (RFI) is to help the U. S. Coast Guard meet the original goals of the LORAN-C program and, in particular, to assist the U. S. Coast Guard staff in identifying and assessing mechanisms for generating and controlling LORAN-C signals. We are using this RFI to gather additional information to help the U. S. Coast Guard to understand the capabilities of waveform generators and control systems technology and to identify qualified vendors who might be able to meet our future requirements. While this RFI focuses on a new LORAN-C pulse generation and control system, the U. S. Coast Guard remains open to alternative ideas and considerations pertaining to the enhancement of the LORAN-C signal availability, integrity, accuracy and continuity. Respondents are encouraged to provide information about alternative methodologies that may help the U. S. Coast Guard better understand the potential of using differing analog / digital / hybrid modulation schemes to assess whether solutions exist to enhance the capability of LORAN-C, while not affecting current users of the LORAN-C system. DESCRIPTION OF INFORMATION REQUESTED All vendors with an appropriate product or capability to produce a product relating to the requirements, set forth in the Potential Requirements Table attached hereto are invited to submit a Capability Statement and contact information. The Capability Statement should discuss the product??s capabilities in meeting the potential requirements, the product??s system requirements, the product??s integration specification (if available), and any other specific and pertinent information that would enhance the U. S. Coast Guard??s understanding of the information submitted. Respondents should also complete the Potential Requirements Table which contains provisional requirements for the waveform generation and control system. We recognize that not all requirements may be met by a single system. Please indicate in your response which capabilities require custom developed solutions. Recommendations for functional or operational requirements for the waveform generation and control system are warranted and will be welcomed. DISCLAIMER This RFI is issued solely for information and planning purposes and does not constitute a solicitation. In accordance with FAR 15.201(e), responses to this notice are not offers and cannot be accepted by the Government to form a binding contract. Respondents are solely responsible for all expenses associated with responding to this RFI. Respondents needing confidential treatment for any proprietary information they furnish must comply with the U. S. Coast Guard??s confidential treatment regulations at 17 C.F.R. 200.83. Responses to this RFI will not be returned. HOW TO RESPOND Please submit your response to this RFI via email to Jeannie Sansone at Jeannie.L.Sansone@uscg.mil, phone 609.523.7258, by Monday, February 20th, 2006, at 10:00 A.M. EST. Techinal questions call 609 523-7204 Mr. David Lown TIMING SIGNALS THAT WILL BE AVAILABLE FOR THE WAVEFORM GENERATOR AND CONTROL SYSTEM. 1. Signals Source. The signals are developed by the USCG Timing Frequency Equipment (TFE). There is an ??Operate?? and a redundant ??Standby?? TFE. Each TFE will produce the timing signals for two independent rates. If necessary for redundancy, two identical sets of signals will be provided via two identical multi-conductor cables (see Table 1 for a further description of that signal cable). All signals (with the exception of the 5 MHz signal) are a single-ended 12 volt waveform. The 5 MHz Clock signal is a 5 volt single-ended square wave. 2. Signals Stability. Signal stability is derived from three cesium frequency standards. 3. Dual Rated Station Signal Designators. Most USCG Loran stations function as parts of two Loran-C ??Chains?? and transmit two different Loran rates. By convention, the rate with the shorter Group Repetition Interval (GRI) is designated as the ??HI Rate??, while the rate with longer GRI is designated as the ??LO Rate??. The timing signal names for the respective rates carry the LO and HI designators. Single rated Loran-C transmitters utilize the LO Rate timing signals. 4. Phase Coding Designators. The groups of 8 or 9 Loran-C pulses are phase coded in a different scheme during alternating GRIs. Two GRIs, A and B, make up what is called the Phase Code Interval (PCI). In this discussion, for clarity sake, the trigger signals associated with phase coding may carry an additional GRI A or GRI B designator (see Figure 1). 5. Description of Timing Signals. The following is a brief description of each of the USCG timing signals that will be provided to the waveform signal generator and control system. 5.1 5 MHz Clock. As stated above, the signal stability derives from three cesium standards. 5 MHz from the cesium becomes the clock within the TFE. This signal will be provided to the waveform generator and control system to be used as the master clock. 5.2 Multipulse Trigger. The Multipulse Trigger (MPT) is the timing strobe that will be provided to the waveform generator and control system to initiate the generator circuitry. There will be one MPT provided for each transmitted pulse, 8 or 9 MPTs in each GRI. The MPTs have a fixed phase relationship with the 5 MHz. When necessary, the TFE will affect timing adjustments in the signal. These adjustments will be accomplished by phase shifting both the MPTs and the 5 MHz clock. 5.3 Phase Code Set, Phase Code Reset. The Phase Code Set (PC SET) and the Phase Code reset (PC RESET) triggers will be provided to the waveform generator and control system to indicate the required phase code of subsequent transmitted pulses. The phase code of the transmitted pulses is different for Master versus Secondary stations, and is also different for GRI A versus GRI B. The PC SET trigger indicates that all subsequent Loran-C pulses shall be transmitted with positive phase code, until such time as the PC RESET trigger is received. Likewise, the PC RESET trigger indicates that all subsequent Loran-C pulses shall be transmitted with negative phase code, until such time as the PC SET trigger is received. (see Figure 3 and figure 4). 6. MPT Variations. There are certain conditions that may require the MPTs to be phase shifted or inhibited. 6.1 Blanking. At dual rated stations there are recurring periods when the transmitted signals of one Loran rate would overlap the second rate. To compensate for this, the TFE blanks, or inhibits the MPTs of one rate during those periods of overlap. Two modes of blanking can be utilized. The first, called priority blanking, is when one rate is always blanked during overlap, while the second, priority rate is never blanked. The second mode, called alternate blanking, alternately blanks both rates during periods of overlap. 6.2 Blink Mode. To alert the navigational users when the transmitted signal may be out of allowable tolerances, the first two pulses in the group of eight, will go into blink mode. In blink mode, the TFE inhibits the MPTs corresponding to the first two pulses of the group for a period of 0.5 seconds out of every 4.5 seconds. Blink mode occurs for Secondary transmissions, only. In the event that a Master transmitted signal may be out of allowable tolerances, all Secondary stations in that Loran-C Chain enter blink mode, and offending Master station??s transmissions may be completely inhibited. 6.3 Pulse Modulation Communications. It is possible to communicate information using transmitted Loran-C signals. Although the Coast Guard does not do so at present, the capability may be desirable in the future. The pulse modulation scheme would be one where timing of pulses 3 through 8 could be independently shifted, + or ?V 5.0 microseconds. Time shifts, of course, would be accomplished by time shifting the corresponding MPTs. LORAN-C GROUP REPETITION INTERVAL AND PHASE CODE INTERVAL The Group Repetition Interval (GRI) is equal in duration to the basic Loran-C Rate. Permissible GRIs are multiples of 10 microseconds from 40000 through 99990 microseconds. The Loran-C rate identifier is the GRI divided by 10 (e.g. 9960 defines a Loran-C Rate with a GRI of 99600 microseconds). The Phase Code Interval (PCI) is equal in duration to two GRIs, commonly labeled GRI A and GRI B. The group of 8 or 9 Loran-C pulses transmitted during GRI A are phased differently than the group transmitted during GRI B (see Appendix B). GRI B +5vdc GRI A GRI A Gnd PCI +12vdc MPTs Gnd First MPT occurs approx. 900 usec after the transition of the PCI signal. FIGURE 1 USCG TIMING EQUIPMENT TYPICAL 5MHZ and MPT SIGNAL LEVELS +5VDC into 50 ohm 5MHZ GND +12VDC 5usec wide MPT GND **Expanded time base** NOTE: Some fixed phase relationship exists between the MPT and the 5MHZ signals. FIGURE 2 FIGURE 3 FIGURE 4 POTENTIAL REQUIREMENTS TABLE # Vendor Name/Product: (fill in vendor name/product) Requirements Provide Capability Y/N Comments High Level 1 The system shall generate a TDW which will result in the transmission of a LORAN-C pulse that is compliant with the Specification of the Transmitted LORAN-C Signal, COMDTINST M16562.4A, Commandant, USCG, May 1994. http://www.navcen.uscg.gov/pubs/loran/sigspec/Default.htm 2 The system shall fully integrate with the current LORAN-C Timing and Frequency Equipment without modification to existing equipment. 3 The system shall be capable of monitoring radio frequency (RF) feedback from the antenna feed point and making automated adjustments to the TDW to maintain the specified LORAN-C signal pulse shape. 4 The system shall not introduce timing errors greater than 10 nanoseconds. 5 The system shall be highly adaptive and capable of coupling to a wide range of amplifiers / transmitters with a wide range of input impedances and amplitude requirements. 6 The system shall be capable of developing TDW for Group Repetition Intervals from 29,000 microseconds to 100,000 microseconds in 10 microsecond steps. 7 The system shall be controllable locally and remotely to allow operators to make adjustments to TDW. 8 The system shall be highly reliable. 9 The system shall be capable of detecting system malfunctions that have the potential to cause the transmitted signal to go out of tolerance. 10 Alarm indications shall be visual, audible, and suitable for transmission over LAN / WAN networks. 11 The system shall have automatically employed, redundant functions designed to reduce the likelihood of transmission interruptions or out of tolerances transmissions. 12 All redundant features shall be remotely selectable via LAN / WAN networks. 13 Future software changes shall not require updates to system hardware. 14 The system shall fit into a standard 19 inch equipment rack with a maximum depth of 28 3/4 inches. 15 The system shall be capable of storing and reporting to the operator(s) adjustments made to the TDW (based upon initial system setup parameters) to allow operators to track changes in the transmitter / amplifier performance. 16 In the event the reference clocks and/or timing triggers from the TFE are lost or interrupted, the system shall remain functional and return to normal operations upon reestablishment of the reference signals. 17 The system should have a modular design to allow for field servicing and repair if needed. 18 The system shall be designed to require minimal maintenance. 19 The system shall be designed to operate in areas with high levels of electromagnetic interference (EMI). 20 The system construction shall be rugged to allow for safe transportation / shipping. 21 The system shall operate on 120 vac +/- 10%.
- Place of Performance
- Address: NOTE Contracting Site Should also read as follows, US Coast Guard, Loran Support Unit, 12001 Pacific Ave, Wildwood, NJ
- Zip Code: 08260
- Country: USA
- Zip Code: 08260
- Record
- SN00976486-W 20060202/060131211624 (fbodaily.com)
- Source
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