Abstract: A wideband interference mitigation module is coupled to an output of a primary downconverter to process the digital intermediate frequency signal. A selective filtering module is associated with a secondary downconverter that comprises a digital harmonic-resistant translator. The selective filtering module comprises: (a) a low-pass filter that is configured as an anti-aliasing digital filter consistent with a target receive bandwidth to suppress aliasing associated with the analog-to-digital conversion, and (b) narrow band rejection filter to filter the digital baseband signal to reduce or to mitigate electromagnetic interference, where the narrow band rejection filter is configured for adaptive control responsive to detection by the wideband interference mitigation module of certain interference in the received radio frequency signal.

Abstract: A wideband interference mitigation module is coupled to an output of a primary downconverter to process the digital intermediate frequency signal. A selective filtering module is associated with a secondary downconverter that comprises a digital harmonic-resistant translator. The selective filtering module comprises: (a) a low-pass filter that is configured as an anti-aliasing digital filter consistent with a target receive bandwidth to suppress aliasing associated with the analog-to-digital conversion, and (b) narrow band rejection filter to filter the digital baseband signal to reduce or to mitigate electromagnetic interference, where the narrow band rejection filter is configured for adaptive control responsive to detection by the wideband interference mitigation module of certain interference in the received radio frequency signal.

Abstract: A demodulator comprises a first-stage carrier demodulator and a second-stage carrier demodulator. The first-stage carrier demodulator is configured to remove or compensate for the tracking error in the baseband signal, where the tracking error comprises aggregate, channel tracking error of carrier phase for the same received band, sub-band, (baseband) GNSS satellite channel, or set GNSS channels. The second stage carrier demodulator is configured to remove or strip a carrier signal component without any unwanted image or carrier-related frequency artifacts and to prepare for correlation-based decoding or demodulation of the encoded baseband signal by the correlators. First correlators are configured to determine correlations for code phase tracking loop, where the code phase tracking loop is configured to estimate a corresponding code error component of the tracking error for the code local oscillator for a respective channel.

Abstract: A system for navigating a mobile object receives satellite navigation signals from a plurality of satellites. Using one or more of the satellite navigation signals from the plurality of satellites, for each respective channel of a plurality of channels, the system generates an estimate of clock error of a clock of the mobile object using a first error correction stage and generates an estimate of a respective carrier tracking error for the respective channel using a second error correction stage that is distinct from the first error correction stage. In accordance with the estimate of the clock error and the estimate of the respective carrier tracking error for each of the plurality of channels, the system computes position and velocity estimates for the mobile object. The system performs a navigation function for the mobile object in accordance with the computed position and velocity estimates for the mobile object.

Abstract: A receiver comprises a mixer that is capable of mixing a selected, received GNSS signal and the local carrier frequency signal (e.g., adjusted with offset signal feedback) or local carrier IF signal to provide a baseband signal. A filter is configured to low-pass filter and to decimate the received samples of digital baseband signal that is encoded by a received pseudo random noise code (PN) sequence. A control module is configured to align temporally one or more received samples of the received PN sequence, or a portion thereof, in a buffer data storage device with a clock edge or symbol transition of the clock signal of a set of local samples of corresponding PN local sequence, or portion thereof, of a local signal or PN replica signal.

Abstract: An improved bubbler has walls formed of thin stainless steel. A hollow cylindrical body member forms a cylindrical sidewall and has welded to it a top end cap and a bottom end cap. A horizontally disposed sparger tube is connected to the carrier-gas inlet tube and is positioned within the bubbler chamber adjacent to the bottom end cap. The sparger tube has a plurality of horizontally spaced-apart exit holes formed therein for providing a plurality of carrier-gas streams into the liquid chemical. The carrier gas bubbles up through the liquid chemical, causing the liquid chemical to vaporize and diffuse into the carrier gas. A substantially uniform temperature throughout the chemical liquid is provided with a heat-conductive enclosure formed of aluminum plates which are thicker than the walls of the bubbler chamber and which contact and entirely surround the exterior surface of the stainless steel bubbler chamber.

Abstract: A liquid level sensor assembly for a liquid-chemical bubbler includes a removable cylindrical LED housing, which is removably retained within a cylindrical axial bore of a sealing nut. The LED housing is removable from within the cylindrical axial bore without breaking the seal between the chemical liquid within the bubbler and the ambient atmosphere. The LED housing holds an LED transmitter and a photodiode detector, which respectively sends light into a cylindrical quartz rod and receives reflected light from the quartz rod, where the reflected light is used to measure the level of the chemical liquid within the bubbler.