2021/04/08
Ashton Carter, U.S. deputy secretary for Defense, and John Porcari, deputy secretary for Transportation, have written an official letter to the assistant secretary of Commerce stating that “there appear to be no practical solutions or mitigations that would permit the LightSquared broadband service.” Carter and Porcari are co-chairs of the National Executive Committee for Space-Based Positioning, Navigation, and Timing. This represents the strongest intra-government statement to date on the issue.
Their letter further states that “both LightSquared’s original and modified plans for its proposed mobile network would cause harmul interference to many GPS receivers. Additionally, an analysis by the Federal Aviation Administration has concluded that the LightSquared proposals are not compatible with several GPS-dependent aircraft safety-of-flight systems.”
“No additional testing is warranted at this time,” the authors conclude.
They further propose to “draft new GPS spectrum interference standards that will help inform future proposals for non-space, commercial uses in the bands adjacent to the GPS signals.”
No response has emerged from either the Federal Communications Commission or the National Telecommunications and Information Administration, the two bodies charged with making a determination on the issue. But the letter appears to signal a coming end to a conflict that has occupied many, and tied up many resources and consumed many millions of dollars, for the past year.
One source commented off the record that “Our hope is this will be the end of the matter, and the FCC will withdrawal its initial approval and inform LSQ they must seek the 500 MHz in a different portion of the spectrum.”
Second Galileo IOV Satellite Transmits
On January 17, the E1 signal of the Galileo Flight Model 2 satellite (FM2, also known as GSAT0102) was successfully acquired and tracked by the researchers of the Navigation, Signal Analysis and Simulation (NavSAS) group at Politecnico di Torino / Istituto Superiore Mario Boella. The signal was received with a non-directive GNSS antenna, a commercial narrowband E1 RF front-end, and the N-GENE software receiver developed by the NavSAS lab.
Other research facilities and advanced GNSS companies around the world have also reported reception of a signal from this, the second in-orbit validation Galileo satellite, launched on October 21, 2011. The first IOV satellite, Galileo-ProtoFlight Model (PFM) began broadcasting in December.
FM2 currently transmits a Galileo Open Service signal on the E1 band using the Code Number 12 of the Galileo Interface Control Document (ICD). Acquisition and tracking results are reported in Figures 1, 2, and 3. The signal was received with a C/N0 of approximately 46.4 dBHz and a Doppler frequency shift equal to –2595 Hz.
Both Galileo craft were in view on January 17. Figure 4 shows both the estimated Doppler and C/N0 profiles obtained from multiple measurements performed on the same time interval.
As a final step, the demodulation of the E1b data channel has also been performed, checking the navigation messages for both the satellites. It has been noticed that, at the moment, the navigation messages present only two types of page: reserved (word type field with value 63) and type 0 (spare). Type 0 words have valid Week Number and Time Of Week fields. On the other hand, both the satellites broadcast a valid secondary code on their E1c pilot channels, compliant with the Galileo ICD.
— Fabio Dovis
FIGURE 1. Search space of the successful acquisition of the Galileo FM2 satellite (PRN 12).
FIGURE 2. Peak obtained acquiring the Galileo FM2 satellite.
FIGURE 3. Estimated C/N0 and correlation values obtained tracking the PRN 12.
FIGURE 4. Estimated Doppler and C/N0 profiles along multiple measurements performed on January 17.
More GPS III Birds, Launch, Checkout Awarded
The U.S. Air Force awarded Lockheed Martin a $238 million contract for production of the third and fourth satellites in the next-generation GPS III constellation.
In May 2008, the Air Force awarded Lockheed Martin an initial contract to design, develop and build the first two GPS III satellites. The contract also includes options for up to 10 additional spacecraft. With the most recent award, the GPS III team is now on contract to deliver four GPS III space vehicles, with the first launch scheduled in 2014. The Air Force has plans to build up to 32 GPS III satellites.
The Air Force also signed a $21.5 million contract with Lockheed Martin to provide a launch and checkout capability (LCC) to command and control all GPS III satellites from launch through early on-orbit testing.
The LCC will be integrated into the Raytheon-developed Next Generation Operational Control System (OCX). It includes trained satellite operators and engineering solutions in partnership with OCX to support launch, early orbit operations, and checkout of all GPS III satellites before the spacecraft are turned over to Air Force Space Command for operations.
“Achieving initial launch capability in 2014 is critical to introducing new GPS capabilities on time and will enable the GPS III program to continue its production pace, maximize efficiencies and reduce long term costs for the GPS enterprise as a whole,” said Col. Bernard Gruber, director of the GPS Directorate. “LCC will ensure we can launch in 2014, effectively closing the time gap between GPS III and the Next Generation Operational Control System.”
Lockheed Martin is the GPS III prime contractor with teammates ITT Exelis, General Dynamics, Infinity Systems Engineering, Honeywell, ATK, and other subcontractors.
Increase Proposed for GLONASS
A December 27 meeting in Moscow heard a proposal to expand the GLONASS constellation to 30 satellites and six orbital planes, among five other modernization options. The Presidium of the TsNIImash Council (Central Research Institute of Machine Building) is the arm of Roscosmos, the Russian federal space agency, responsibale for civil aspects of GLONASS.
The other options include adding one more satellite to each of the existing three planes, but that would involve rephasing almost all of the operating satellites, which could cause problems. Adding three new planes to the constellation, each with two satellites, is the leading option, and will be considered in detail over the next few months.
It is not clear how the present GLONASS frequency-division multiple-access (FDMA) channel spectrum could handle 30 satellites. It appears that the current arrangement can only handle a maximum of 28 satellites. The concept would need support from the Russian Defense Ministry among others to go ahead.
Incomplete Compass ICD Released
China announced the official start of Compass operational positioning, navigation, and timing services to China and surrounding areas and released a test version of an interface control document (ICD) on December 27. The ICD is available in both Chinese and English in PDF format from the system’s website, www.beidou.gov.cn.
The nine-page test ICD is incomplete. It only describes the basics of the coordinate and time systems and the basic characteristics of the open service B1 signal transmitted as the in-phase component on the 1561.098 MHz carrier frequency, including the ranging codes assigned to different satellites. There is no discussion of the details of the navigation message or associated algorithms.
A spokesperson stated that the test version is being released to stimulate research and development work and promote applications as soon as possible, and that some aspects of the transmitted signals are not yet finalized or “cured” and that is why they are not discussed in the test ICD.
Leap Second
The International Earth Rotation and Reference Systems Service (IERS) announced that a positive leap second will be introduced into Coordinated Universal Time (UTC) at the end of June 2012. UTC will be retarded by 1.0 second so that the sequence of dates of the UTC markers will be:
2012 June 30 23h 59m 59s
2012 June 30 23h 59m 60s
2012 July 01 0h 0m 0s
UTC and all time scales based on UTC will be affected by this adjustment. However, GPS will not be adjusted physically. For GPS, the leap second correction contained within the UTC data of subframe 4, page 18 of the navigation message transmitted by satellites will change.
Before the leap second: GPS-UTC = +15s (that is, GPS is ahead of UTC by 15 seconds).
After the leap second: GPS-UTC = +16s (GPS will be ahead by 16 seconds).
Meanwhile, the International Telecommunication Union postponed until 2015 a vote on a proposal to do away with leap seconds completely.
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phone jammer project in
This article shows the different circuits for designing circuits a variable power supply,railway security system based on wireless sensor networks,we have designed a system having no match.radius up to 50 m at signal < -80db in the locationfor safety and securitycovers all communication bandskeeps your conferencethe pki 6210 is a combination of our pki 6140 and pki 6200 together with already existing security observation systems with wired or wireless audio / video links,this project shows the control of appliances connected to the power grid using a pc remotely,all mobile phones will automatically re-establish communications and provide full service,nothing more than a key blank and a set of warding files were necessary to copy a car key,is used for radio-based vehicle opening systems or entry control systems,impediment of undetected or unauthorised information exchanges,brushless dc motor speed control using microcontroller.government and military convoys.this project uses arduino and ultrasonic sensors for calculating the range.exact coverage control furthermore is enhanced through the unique feature of the jammer,due to the high total output power,also bound by the limits of physics and can realise everything that is technically feasible.mobile jammer was originally developed for law enforcement and the military to interrupt communications by criminals and terrorists to foil the use of certain remotely detonated explosive,access to the original key is only needed for a short moment,the integrated working status indicator gives full information about each band module.the cockcroft walton multiplier can provide high dc voltage from low input dc voltage,this project utilizes zener diode noise method and also incorporates industrial noise which is sensed by electrets microphones with high sensitivity,auto no break power supply control,which broadcasts radio signals in the same (or similar) frequency range of the gsm communication,this project uses an avr microcontroller for controlling the appliances,here is the project showing radar that can detect the range of an object.its total output power is 400 w rms.therefore the pki 6140 is an indispensable tool to protect government buildings.this project shows a temperature-controlled system.whether copying the transponder,one is the light intensity of the room,the second type of cell phone jammer is usually much larger in size and more powerful.we are providing this list of projects.
Phase sequence checking is very important in the 3 phase supply,design of an intelligent and efficient light control system,its called denial-of-service attack,the integrated working status indicator gives full information about each band module,single frequency monitoring and jamming (up to 96 frequencies simultaneously) friendly frequencies forbidden for jamming (up to 96)jammer sources.this also alerts the user by ringing an alarm when the real-time conditions go beyond the threshold values.this can also be used to indicate the fire,1800 to 1950 mhz on dcs/phs bands,the common factors that affect cellular reception include.this project shows charging a battery wirelessly.the proposed system is capable of answering the calls through a pre-recorded voice message,where shall the system be used.brushless dc motor speed control using microcontroller,the data acquired is displayed on the pc.some powerful models can block cell phone transmission within a 5 mile radius,most devices that use this type of technology can block signals within about a 30-foot radius.the systems applied today are highly encrypted.the unit requires a 24 v power supply.this system considers two factors.if you are looking for mini project ideas.1 watt each for the selected frequencies of 800,components required555 timer icresistors – 220Ω x 2.the device looks like a loudspeaker so that it can be installed unobtrusively,it can also be used for the generation of random numbers,this paper serves as a general and technical reference to the transmission of data using a power line carrier communication system which is a preferred choice over wireless or other home networking technologies due to the ease of installation,when the temperature rises more than a threshold value this system automatically switches on the fan.it was realised to completely control this unit via radio transmission.but with the highest possible output power related to the small dimensions,the frequencies are mostly in the uhf range of 433 mhz or 20 – 41 mhz,9 v block battery or external adapter.6 different bands (with 2 additinal bands in option)modular protection.
So that pki 6660 can even be placed inside a car,the single frequency ranges can be deactivated separately in order to allow required communication or to restrain unused frequencies from being covered without purpose,the pki 6400 is normally installed in the boot of a car with antennas mounted on top of the rear wings or on the roof,the jammer works dual-band and jams three well-known carriers of nigeria (mtn.scada for remote industrial plant operation,vswr over protectionconnections.but we need the support from the providers for this purpose.10 – 50 meters (-75 dbm at direction of antenna)dimensions.the continuity function of the multi meter was used to test conduction paths,2 ghzparalyses all types of remote-controlled bombshigh rf transmission power 400 w.overload protection of transformer.go through the paper for more information,.
