# US 2019/0316951 A1 · Tank Multi-Level Measurement Using Through the Air Millimeter Wave Radar > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0316951 A1 - Document ID: US20190316951A1 - Status: Published application - Kind: A1 - Application number: 16/382,019 - Filed: 2019-04-11 - Published: 2019-10-17 - Earliest claimed: 2018-04-11 - Assignees: Lasso Technologies, LLC - Applicants: Lasso Technologies, LLC - Inventors: Peter E. McCormick - Web page: https://patentgrep.com/patent/US20190316951A1 ## CPC - G01F 23/2845: {for discrete levels (G01F23/288, G01F23/292 take precedence)} - G01S 13/88: Radar or analogous systems specially adapted for specific applications (electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00) - G01F 23/18: Indicating, recording or alarm devices actuated electrically - G01F 23/284: Electromagnetic waves - G01F 23/804: {containing circuits handling parameters other than liquid level} - G01S 13/08: Systems for measuring distance only (indirect measurement G01S13/46) - G01S 13/34: using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract Methods and systems for determining fluid levels in a tank comprise a mmWave Control unit configured to generate a millimeter wave chirp that ramps linearly from a starting frequency to a higher frequency within a specified time span. The mmWave Control unit transmits the chirp into the tank and receives one or more chirp reflections from the tank. The mmWave Control unit mixes the chirp with the chirp reflections to generate one or more intermediate frequency signals and processes the one or more intermediate frequency signals to derive one or more distances, each distance representing the distance from the top of the tank to one of the one or more fluids in the tank or an obstruction in the tank. A Telemetry Control unit automatically selects intermediate frequency signals having a signal strength above a predefined minimum or distances within a predefined distance window for further processing. ## Claims ### Claim 1 A tank level instrument for measuring a distance from near a top of a tank to one or more fluids in the tank, comprising: a chirp generator operable to generate a millimeter wave chirp that ramps linearly from a starting frequency to a higher frequency within a specified time span; a transmit antenna configured to transmit the chirp generated by the chirp generator into the tank; a receive antenna configured to receive one or more chirp reflections from the tank, a mixer operable to mix the chirp transmitted by the transmit antenna with the chirp reflections received by the receive antenna to generate one or more intermediate frequency signals; a processing unit operable to process the one or more intermediate frequency signals and derive one or more distances from the one or more intermediate frequency signals, each distance representing the distance from near the top of the tank to one of the one or more fluids in the tank or an obstruction in the tank; and a computer operable to automatically select intermediate frequency signals having a signal strength above a predefined minimum or distances within a predefined distance window for further processing and ignore other intermediate frequency signals and distances. ### Claim 2 (depends on 1) The tank level instrument according to claim 1, wherein the starting frequency of the chirp is above 60 GHz and a bandwidth of the chirp is 4 Ghz or more. ### Claim 3 (depends on 1) The tank level instrument according to claim 1, wherein the processing unit is operable to process the one or more intermediate frequency signals using Zoom Fourier transform. ### Claim 4 (depends on 1) The tank level instrument according to claim 1, further comprising an enclosure mounted on the tank over an opening in the tank, the enclosure isolating the chirp generator, the transmit antenna, the receive antenna, the mixer and the processing unit from the tank, the enclosure being made partly or entirely of a material having a dielectric constant that is sufficiently low to allow the chirp and the chirp reflections to pass through the enclosure with a signal strength loss that is less than a specified minimum. ### Claim 5 (depends on 4) The tank level instrument according to claim 4, wherein the material of the enclosure has a dielectric constant that is less than 5. ### Claim 6 (depends on 4) The tank level instrument according to claim 4, wherein the material of the enclosure is impervious to the one or more fluids in the tank. ### Claim 7 (depends on 4) The tank level instrument according to claim 4, wherein the same enclosure also isolates the computer from the tank. ### Claim 8 (depends on 4) The tank level instrument according to claim 4, wherein the computer is operable to ignore distances representing the distance between the top of the tank and chemical residue that may collect on the enclosure. ### Claim 9 (depends on 1) The tank level instrument according to claim 1, wherein the computer is operable to ignore distances that represent the distance between the top of the tank and one or more of foam, gas, fog, mist, ice, sand, debris, chemical residue, and obstructions in a tank. ### Claim 10 (depends on 1) The tank level instrument according to claim 1, further comprising wireless telemetry connected to the computer and operable to transmit the distances selected by the computer to a remote location. ### Claim 11 (depends on 10) The tank level instrument according to claim 10, wherein the wireless telemetry includes one or more of cellular telemetry and satellite telemetry. ### Claim 12 (depends on 1) The tank level instrument according to claim 1, wherein the computer is further operable to identify a dissimilar fluid interface by determining whether a first intermediate frequency signal is followed by a second intermediate frequency signal having a lower signal strength than the first intermediate frequency signal, both the first and second intermediate frequency signals having signal strengths above the minimum. ### Claim 13 (depends on 1) The tank level instrument according to claim 1, wherein the tank level instrument a self-contained unit. ### Claim 14 (depends on 1) The tank level instrument according to claim 1, further comprising a visual display for allowing a user to selectively display a fluid level or a fluid volume in the tank. ### Claim 15 (depends on 1) The tank level instrument according to claim 1, wherein the processing unit is operable to send the one or more intermediate frequency signals to an external computer for further processing. ### Claim 16 (depends on 1) The tank level instrument according to claim 1, further comprising an open-sided horn connected to the transmit antenna, the open-sided horn composed of two plates connected to each other at an angle. ### Claim 17 A tank level instrument for measuring a level of fluid in a tank, comprising: a mmWave Control unit configured to generate a millimeter wave chirp that ramps linearly from a starting frequency to a higher frequency within a specified time span, the mmWave Control unit further configured to transmit the chirp into the tank and receive one or more chirp reflections from the tank, the mmWave Control unit further configured to mix the chirp with the chirp reflections to generate one or more intermediate frequency signals and process the one or more intermediate frequency signals to derive one or more distances, each distance representing the distance from near a top of the tank to a fluid in the tank or an obstruction in the tank; and a Telemetry Control unit configured to automatically select intermediate frequency signals having a signal strength above a predefined minimum or distances within a predefined distance window for further processing. ### Claim 18 (depends on 17) The tank level instrument according to claim 17, further comprising a single enclosure, wherein the mmWave Control unit and the Telemetry Control unit are enclosed within the single enclosure. ### Claim 19 A method of measuring a level of fluid in a tank, comprising: generating a millimeter wave chirp that ramps linearly from a starting frequency to a higher frequency within a specified time span; transmitting the chirp into the tank; receiving one or more chirp reflections from the tank; mixing the chirp with the chirp reflections to generate one or more intermediate frequency signals; processing the one or more intermediate frequency signals to derive one or more distances, each distance representing the distance from near a top of the tank to a fluid in the tank or an obstruction in the tank; and automatically selecting intermediate frequency signals having a signal strength above a predefined minimum or distances within a predefined distance window for further processing. ### Claim 20 (depends on 19) The method according to claim 19, wherein the generating, transmitting, receiving, mixing, processing, and automatically selecting are performed from within a single enclosure.