Patent Description:
In practice, GNSS receivers calculate a new point up to <NUM> times per second. The quality of the point, however, can change from good to bad and back to good several times per second. The change in quality can be caused by different factors including rapid changes in satellite reception and/or conditions or by procedural error(s) introduced by a user. For example, a user may decide to collect a point that seems high quality, but in the time it takes to make the motion to issue the "collect" or "save" command the point broadcast as a GNSS message may change.

In addition, as field data collection processes make greater use of and place greater reliance on technology 'gadgets,' users are more commonly burdened with operating several devices simultaneously. Unfortunately, a single individual oftentimes simply does not have enough hands to correctly operate all of the equipment in a manner that produces the optimal quality. <NPL> disclose improving GPS positioning accuracy with context awareness by calibrating GPS position using the context awareness techniques from Pervasive Computing. From the inspiration of the pervasive computing research, this paper proposes a novel approach, called PGPS (Perceptive GPS), to directly improve GPS positioning accuracy from the contextual information of received GPS data. PGPS is started with sampling received GPS data to learning carrier's behavior and building a transition probability matrix based upon HMM (Hidden Markov Model) model and Newton's Laws. After constructing the required matrix, PGPS then can interactively rectify received GPS data in real time. That is, based on the transition matrix and received online GPS data, PGPS infers the behavior of GPS carrier to verify the rationality of received GPS data. In particular, a Fuzzy Logic approach is used to determine the accuracy of a GPS receiver position, which can select a more accurate position according to preset rules of Position Dilution of Precision (PDOP) and SNR If the received GPS data deviate from the inferred position, the received GPS data is then dropped. <NPL> discloses methods and strategies of the network update of the land survey spatial data based on embedded terminal equipment and server and application of multilevel distributed heterogeneous land spatial database. This paper discloses using a DGPS device used for land surveying, positioning, and other information collection which can automatically provide a three-dimensional positioning data under the dynamic conditions within a few seconds.

<CIT> discloses farming land parcel graph construction and precision management middleware based on a BD and a GIS. The farming land parcel graph construction and precision management middleware comprises a data processor, a locating module and a data transmitting module, and the locating module and the data transmitting module are respectively connected with the data processor. This disclosure mentions that marking of the features requires the use of a handheld terminal with a middleware. The surveyor carries the hand-held terminal and walks around the plot to be measured. Each step is taken (the speed measurement accuracy can reach <NUM>/s). The middleware will pick and locate the current position through the Beidou navigation function of the positioning module. Latitude and longitude and altitude are transmitted to the parcel composition module.

<CIT> discloses a surveying apparatus including an antenna to receive a positioning signal. The surveying apparatus further includes a tilt sensor to obtain a tilt measurement that indicates a degree of tilt of the survey apparatus. The surveying apparatus further includes a processor to obtain a positioning measurement from the positioning signal, and to determine a degree of accuracy of the positioning measurement based on the tilt measurement.

The invention includes a method and apparatus intended for improving, such as through smart automations, data quality from and ease of use of pole mounted GNSS antennas or systems.

Embodiments of this invention include a method of improving data quality using GNSS according to claim <NUM>. The invention further includes an apparatus for improving data quality in GNSS according to claim <NUM>. detailed herein, the invention can desirably make field collection of GNSS locations easier and more accurate by eliminating user steps and potential user errors. The apparatus (e.g., software and/or hardware) and method of this invention generally operate as a middleware between a user's existing GNSS receiver and GIS mobile software, to intercept and/or filter GNSS standard messages. In embodiments, the GNSS messages are analyzed for preconfigured conditions while sensors measure the pole angle or tilt. When the pole is held vertical and conditions within the stream of GNSS messages are met, the middleware software and/or controller locks onto the point and repeats the point's GNSS message so that the GIS software can collect the point.

Other objects and advantages will be apparent to those skilled in the art from the following detailed description taken in conjunction with the appended claims and drawings.

As described in greater detail below, the invention generally relates to a method and apparatus for improving GNSS data gathering, with features termed as smart GNSS automations. In embodiments of this invention, the method and/or device provides automated determination of predetermined preferred use conditions, and filters the GNSS data (e.g., NMEA data) received via the GNSS receiver as a function of the conditions, by locking a location point and its corresponding GNSS data upon determining the conditions are met. The preconfigured condition(s) can include one or more of, for example, an angle or tilt of the GNSS receiver and/or signal quality conditions such as number of satellites in solution, a distance root mean squared (DRMS) value, a horizontal dilution of precision (HDOP) value, and/or fix quality.

In embodiments of this invention, the device and method provide automated measuring of an angle or tilt of a GNSS receiver, and automated filtering of GNSS data received via the GNSS receiver as a function of the measured angle or tilt. By this invention, for example, the best location point information can be automatically coordinated to a sufficiently vertical position of the GNSS receiver, and the point reading only taken if the sufficient vertical position is obtained. User error in thus reduced or eliminated.

The smart GNSS automations of embodiments of this invention do not compensate for user error. Instead the subject helper automations encourage proper GNSS collection techniques which in turn produce or result in the highest quality data. The smart GNSS automations of the invention also do not introduce new 'gestures', but instead they intelligently monitor several factors and make an independent decision on when to collect a location point.

An additional advantage of the invention is that it can work with any GNSS device and/or mobile GIS software, such as those Bluetooth® compatible and/or which communicate via, for example, industry standard NMEA messages. Users of this system can keep their existing hardware and software. They do not need to buy a high end GNSS system or retrain on their personnel on the use of these systems.

<FIG> schematically illustrates a use of a GNSS receiver for point surveying, according to one embodiment of this invention. A user <NUM> has a GNSS survey pole <NUM> with a GNSS antenna <NUM> and a GNSS receiver <NUM> mounted thereon. The receiver <NUM> can alternatively be a hand-held unit or in some cases can even be a hand-held unit without a survey pole. The receiver <NUM> further includes an internal or external communications output (e.g., wired or wireless), antenna, or other equivalent for communicating with a GIS system <NUM> (e.g., a user tablet) and/or optionally transmitting to or receiving information from remote personnel and systems <NUM>, such as by radio or cellular transmissions. The GNSS antenna <NUM> receives signals from GNSS satellites <NUM>. The GNSS survey pole <NUM> is shown at a first location point <NUM>. The user <NUM> places the tip of the survey pole <NUM> at the survey point <NUM>, holds the pole <NUM> level (vertical) so that the center of GNSS antenna <NUM> is located over the survey point <NUM>, and takes readings. The pole <NUM> is subsequently moved by the user <NUM> to further location points <NUM> and <NUM> during use for further measurements.

The GNSS receiver <NUM> of <FIG> includes a middleware according to embodiments of this invention for improving the accuracy of the location point determination. The middleware can be software stored in and/or executed by the GNSS receiver <NUM>. The middleware can also be embodied via a separate device connected to the GNSS receiver <NUM> (e.g., wired or wireless), such as with a housing mounted to the pole <NUM> for user efficiency. As shown in <FIG>, a device of embodiments of this invention desirably includes a housing <NUM> with a display <NUM>, and enclosing one or more sensors in combination with a control module. Any suitable sensors can be used, such as accelerometers, gyroscopes, degree of freedom sensors, etc. Ultrasonic or laser measurement can also be used. Additionally the device includes processors, non-transitory recordable memory components including executable software code and for data storage, such as a cache memory, and other computer components for operation and to implement the method of this invention.

<FIG> shows a block diagram of a GNSS receiver system <NUM> according to embodiments of this invention. The GNSS antenna <NUM> sends satellite information to the receiver <NUM>. Instead of the receiver transmitting the satellite information directly to the mapping system <NUM>, such as a GIS system, the satellite information first goes through, and is filtered by middleware <NUM> (software and/or device) according to this invention.

Referring to <FIG>, the user <NUM> places the pole <NUM> on survey point <NUM>. When the middleware determines that the conditions are met, the middleware automatically locks onto a location point from the GNSS receiver. In presently preferred embodiments, the middleware uses or includes a plumb or level sensor that determines the orientation of the pole <NUM> relative to the vertical. When the middleware control module determines that the pole <NUM> is sufficiently close to vertical, according to a predetermined value, and any other preconfigured condition(s) is/are also met, the middleware locks onto a location point from the GNSS receiver. In embodiments of this invention, the device can lock a location point when the pole <NUM> is within any predetermined angle from vertical, such as <NUM>% from vertical, desirably <NUM>% from vertical, and preferably <NUM>-<NUM>% from vertical.

In embodiments of this invention, the middleware replaces a continuing live stream of GNSS messages with a broadcast of the GNSS message of the locked location point, such as by with a repeated broadcast of the GNSS message of the locked location point. The middleware thereby filters the GNSS data provided to, for example, the downstream GIS system, by providing only the GNSS message of the desired, locked vertical position. The user <NUM> is thus relieved from maintaining the vertical orientation, thereby reducing user error and freeing the user to collect/input other information according to the job assignment. In embodiments of this invention, the device continues blocking the live stream and forwarding the repeated broadcast until the user clears the device for the next measurement.

As a further example of using the middleware to collect GNSS point estimates with more confidence that user introduced errors have been minimized, as illustrated in <FIG>, the operation allows a field personnel to set aside a mobile data collection tablet, and focus on accurately placing the survey pole at the correct location. The field personnel instructs the middleware to unlock to clear any previous inadvertent lock, and the middleware desirably displays visual indicators of quality criteria status, such as including an electronic bubble level on a device display. The field personnel holds the survey pole plumb based on the electronic bubble level display. When all quality criteria are met, such as illustrated in <FIG>, the middleware locks the point and caches in memory a segment of GNSS sentences containing the high quality positional data. The middleware intercepts the live GNSS stream coming from the GNSS device and instead repeatedly rebroadcasts the high quality GNSS stream cache. Upon seeing a confirmation of the lock on the display, the field personnel can set aside the survey pole and receiver, pick up the mobile data collection tablet, and focus on recording an accurate record within the mobile GIS software. Once the record has been recorded the field personnel can unlock the system so that it is ready to collect the next position.

Systems and assemblies in accordance with embodiments of the invention preferably satisfy at least one or more of the following functional requirements. The system desirably provides opportunities to improve quality of field location data collected using GNSS receivers. To achieve this, the system desirably automates appropriate steps of the collection process. The system desirably is able to sense the degree the pole is held out of plumb and provide the user some indication of the plumb status via visual display. The system desirably is able to intercept, for example, GST, GSA, GSV, and GGA type NMEA sentences via a connection (e.g., via a serial port) to a GNSS receiver. The system is desirably able to parse, without limitation, the following information from the NMEA messages: GST (latitude and longitude standard deviation values); GGA (current fix quality); GGA (horizontal dilution of precision (HDOP)); GGA (number of satellites); GSV (signal to noise ratio for satellite ID); and/or GSA (satellite IDs used). The system desirably detects when a segment of GNSS sentences has met any preconfigured quality indicators. The system desirably caches those high-quality messages and repeatedly send those message to the mobile tablet instead of the real-time GNSS being produced by the GNSS receiver. The system desirably allows the user to unlock the GNSS repeat mode via a button. The system desirably displays to the user in some visual manner such as a light, blinking light or icon the indicating status of the system and real-time status of quality components which trigger the hold point.

The system desirably enters a test mode on user request to validate the configured quality criteria. The test will be completed in area where the GNSS device can receive satellite signals and any required correction data. The test logic will validate that the GNSS is sending NMEA, for example, which make it possible to achieve a point lock. For example, if the quality configuration requires a RTK Fix, the test can look for RTK Float or Fix messages verifying that the GNSS is in RTK mode and receiving correction data. The system desirably supports a normal mode and a relaxed mode for quality configuration criteria. The user desirably is able to activate the relaxed mode for a single point at a time. The criteria categories desirably include one or more of: plumb level, valid NMEA, constellations in use, GST reported standard deviation, live sample 2DRMS, GGA fix quality, GGA HDOP, GGA number of satellites, and GSA to GSV SNR filter.

Desirable features and/or characteristics of the user interface include one or more of the following. The system desirably minimizes the number of devices that the operator needs to manage in the process of data collection. Any visual indicator desirably is visible in daylight conditions up to six feet away. Desirable performance requirements characteristics of the device include a rechargeable battery with a life that matches common GNSS receivers.

Interface requirement constraints for interactions with other systems, such as transferring data, may include one or more of the following. The system may desirably receive and transmit data via, for example, a serial port to and from a USB or Bluetooth connected GNSS device. The system desirably is able to receive NMEA or equivalent formatted messages from the GNSS. In some configurations, such as RTK operational modes, the system desirably is able to forward RTCM formatted correction messages to the GNSS device. The system desirably can receive and transmit data via, for example, a serial port to and from a USB or Bluetooth connected mobile tablet. The system desirably is able to send NMEA formatted messages to the mobile tablet. In some configurations, such as RTK operational modes, the system desirably is able to forward RTCM formatted correction messages from the mobile tablet. The system desirably provides hardware interfaces, for example R2 USB ver. <NUM> Type A, preferably with multiple connections to support connections to the GNSS equipment.

<FIG> illustrate operations of a device <NUM> for implementing the middleware according to embodiments of this invention. The device <NUM> includes a housing <NUM> and a display screen <NUM>. The display screen is used to communicate to the user whether the device (and survey pole) is level, and any other information relevant to the device and/or GNSS data gathering. As illustrated, the display screen includes an array (<NUM> x <NUM>) of individual LED lights <NUM>, preferably each capable of more than one color. In <FIG>, the darkened circles represent illuminated lights <NUM>.

In the embodiment of <FIG>, the display <NUM> includes four corner quadrants <NUM> (<NUM> x <NUM>) that are illuminated, creating level-indicating light channels <NUM> therebetween. The internal control module of the device <NUM> communicates a plumb or level reading via the lights <NUM> on the display <NUM>. <FIG> shows a display <NUM> when the survey pole is tilted five degrees from vertical, away from the user. In <FIG> the lights are illuminated further from a center of the array, and shows a display <NUM> when the survey pole is tilted ten degrees from vertical, away from the user. <FIG> shows a display <NUM> when the survey pole is tilted fifteen degrees from vertical, away from the user, and <FIG> shows a display <NUM> when the survey pole is tilted twenty or more degrees from vertical, away from the user. <FIG> illustrate when the pole is tilted five, ten, fifteen, and twenty or more degrees, respectively, in a different direction to that of <FIG>, namely to the right of the user. Different colors can further be used in addition to the moving lights for ease of user recognition. For example, the displays of <FIG> can use yellow lights to indicate a further distance from vertical, and <FIG> and <NUM>-<NUM> can use red lights to indicate being very far from vertical.

<FIG> shows the display <NUM> when the pole is held within an acceptable vertical position, such as two degrees level in both the left-right and front-back orientation. Additionally, the four quadrants can display colors, such as all four quadrants are green indicating that the current signal has met all quality criteria. In the orientation of <FIG>, the system would lock the location point, and can show a lock icon. Additional or alternative sizes, shapes, or configurations are available to display the level sensor readings. For example, the four corner quadrants can change color (green-yellow-red) to indicate a vertical plumb position, or lack thereof, and/or whether other quality conditions are met. Also, a LCD or equivalent screen can be used and incorporate any suitable alphanumeric or pictorial level-indicating representation. Haptic or audible signals can be used alternatively or additionally. In addition, the display can include scrolling or other messages to the user, such as indicating normal vs. relaxed modes, signal fix issues, calibration or rest events/errors, or a location lock, such as displaying a padlock image.

Thus the invention provides a method, such as implemented in a middleware software or device for new or existing GNSS equipment, that allow for GNSS point collection in the GNSS software at a difficult location with less burden on the field user. A GNSS point estimate is collected in the GNSS software with more confidence that user-introduced errors have been minimized.

The invention illustratively disclosed herein suitably may be practiced in the absence of any element, part, step, component, or ingredient which is not specifically disclosed herein.

Claim 1:
A method of improving data quality using GNSS, the method comprising:
automatically analyzing a stream of GNSS messages from a GNSS receiver (<NUM>) for a preconfigured condition;
automatically filtering the GNSS data received via the GNSS receiver (<NUM>) as a function of the preconfigured condition; and
automatically providing the filtered GNSS data to a GIS system (<NUM>),
wherein the method further comprises automatically locking onto a location point (<NUM>, <NUM>, <NUM>) reading of the GNSS receiver (<NUM>) when the preconfigured condition is met; and
wherein the filtering comprises repeating the GNSS message of the single locked location point (<NUM>, <NUM>, <NUM>) reading determined as a function of the preconfigured condition to the GIS system (<NUM>).