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LORD 3DM-GX4-45 User Manual

Gps-aided inertial navigation system
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LORD USER MANUAL
™
3DM-GX4-45
GPS-Aided Inertial Navigation System (GPS/INS)

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Summary of Contents for LORD 3DM-GX4-45

  • Page 1 LORD USER MANUAL ™ 3DM-GX4-45 GPS-Aided Inertial Navigation System (GPS/INS)
  • Page 2 MicroStrain Sensing Systems 459 Hurricane Lane Suite 102 Williston, VT 05495 United States of America Phone: 802-862-6629 Fax: 802-863-4093 http://www.microstrain.com sensing_support@LORD.com sensing_sales@LORD.com Copyright © 2014 LORD Corporation ® ® ™ ® ® ® ™ ™ ™ , 3DM-DH , 3DM-DH3...

  • Page 3: Table Of Contents

    ™ 3DM-GX4-45 Inertial Navigation System User Manual Table of Contents System Overview Sensor Overview 2.1 Components 2.2 Interface and Indicators Basic Setup and Operations 3.1 Software Installation 3.2 System Connections 3.3 Software Interface 3.3.1 Interactive Help Menu 3.4 Sensor Communication 3.5 GPS Link...
  • Page 4 ™ 3DM-GX4-45 Inertial Navigation System User Manual 4.4.3 Sensor Frame 4.4.4 Platform Frame Performance Optimization 5.1 Magnetometer Calibration 5.2 Gyroscope Bias 5.3 Heading Drift and Compensation 5.4 Angular Rate and Acceleration Limits 5.5 Bandwidth 5.6 Platform Frame Transformation 5.7 GPS Parameters 5.8 GPS Antenna Offset...
  • Page 5 ™ 3DM-GX4-45 Inertial Navigation System User Manual 7.1 Data Communications Protocol (DCP) 7.1.1 Packet Builder 7.1.2 Sensor Direct Mode 7.1.3 GPS Direct Mode 7.2 Sensor Wiring 7.3 Alternate GPS Equipment 7.3.1 GPS External Receiver 7.4 Sampling on Start-up 7.5 Connecting to a Datalogger 7.6 Using Wireless Adapters...
  • Page 6 ™ 3DM-GX4-45 Inertial Navigation System User Manual 13.1.2 GPS Antenna Specifications 13.1.3 Power Supply Specifications (RS232 kits only) 13.1.4 Communication and Power Cables 13.2 Reference Documents 13.3 Glossary...

  • Page 7: 3Dm-Gx4-45 ™ Inertial Navigation System User Manual

    ™ as RS232 and USB. The LORD MicroStrain  Monitor software can be used for device ® configuration, real time measurement monitoring, and data recording. The LORD MicroStrain ™ ®  Data Communications Protocol that is used to communicate with LORD MicroStrain inertial sensors is also available for users who want to develop customized software solutions.

  • Page 8: Sensor Overview

    LORD MicroStrain  Monitor software that is provided ® with system starter kits, and also available as a free download from the LORD MicroStrain ® website. Alternatively, users can write custom software with the LORD MicroStrain open source data communication protocol.

  • Page 9: Components

    ™ needed to begin using it. The starter kits include the 3DM-GX4-45 inertial sensor, a serial communications cable (either RS232 or USB), a power supply with country plug adapter (RS232 kits only), an external GPS antenna with a three meter cable, a non-magnetic GPS antenna adapter cable, and all software, drivers, and documentation. ...

  • Page 10: Interface And Indicators

    Sensor Overview User Manual 2.2 Interface and Indicators ™ The 3DM-GX4-45 sensor interfaces include a dual use communications and power input connector and a GPS antenna port. The sensor is mounted using the mounting and alignment holes as needed (see Sensor Mounting on page 48).

  • Page 11: Basic Setup And Operations

    To acquire sensor measurements and computed outputs, the 3DM-GX4-45 is used with a host ® computer capable of serial communication, and a software interface.  The LORD MicroStrain ™  Monitor software is provided with the system and includes all functions needed for sensor ®...

  • Page 12: Software Installation

    ™ 3DM-GX4-45 Inertial Navigation System Basic Setup and Operations User Manual 3.1 Software Installation NOTE ™ The MIP  Monitor Software Suite includes hardware drivers required for all ™ 3DM-GX4 sensors.  Sensors will not be recognized without these drivers. ™ To install MIP  Monitor ...

  • Page 13: System Connections

    (as applicable for RS232 communications), GPS antenna, GPS antenna adapter cable, and a host computer with access to the data ® ™ acquisition software, such as LORD MicroStrain  Monitor. Figure 5 - System Connections...

  • Page 14: Software Interface

    ™ 3DM-GX4-45 Inertial Navigation System Basic Setup and Operations User Manual 3.3 Software Interface ™ The MIP  Monitor software includes a main window with system information and menus, a device settings window ( see Sensor Settings on page 16 ), and several data monitoring...

  • Page 15: Sensor Communication

    ™ 3DM-GX4-45 Inertial Navigation System Basic Setup and Operations User Manual 3.4 Sensor Communication Once power has been applied to the sensor, it is on. The sensor selects the appropriate serial communication (USB or RS232) on power- up based on which cable is connected. If the hardware drivers have been installed, communication can be established using the ™...

  • Page 16: Gps Link

    ™ 3DM-GX4-45 Inertial Navigation System Basic Setup and Operations User Manual 3.5 GPS Link NOTE The GPS antenna requires unobstructed line of sight with the sky in order to achieve communication with the GPS  satellites. Communication between the GPS receiver and GPS satellites is initiated when the 3DM-GX4- ™...
  • Page 17 ™ 3DM-GX4-45 Inertial Navigation System Basic Setup and Operations User Manual 1. The following describes the Device Settings interface: a. Main menu tabs: The main tabs break up the setting into broad functional groups for the types of measurement available. For the 3DM- ™...

  • Page 18: Saving Configurations

    ™ 3DM-GX4-45 Inertial Navigation System Basic Setup and Operations User Manual 3.6.1 Saving Configurations Sensor settings are saved temporarily by selecting the OK button in the Device Setup window after configuration, but are lost when the device is powered off. To save current settings in the device memory for future use, the Save Current Settings feature is used.

  • Page 19: Data Monitoring And Recording

    ™ 3DM-GX4-45 Inertial Navigation System Basic Setup and Operations User Manual 3.7 Data Monitoring and Recording NOTE During viewing and recording, only the outputs that are selected in the Message Format tabs in the Device Setup menu are displayed and recorded (see Sensor Settings on page 16).
  • Page 20 ™ 3DM-GX4-45 Inertial Navigation System Basic Setup and Operations User Manual There are several data monitoring views available depending on what measurements are desired for monitoring and recording. Each view corresponds to one of the main categories in ™ the Device Settings window. For example, the 3DM - GX4 - 45...
  • Page 21 Microsoft Excel NOTE If the data is recorded in Binary format it will require a translation program that ® ™ utilizes the LORD MicroStrain  Data Communications Protocol to make it user-readable. Figure 13 - Record Data 5.

  • Page 22: Viewing Data

    CSV files can be viewed with Microsoft Excel, Quattro Pro, Open Office, or other CSV editors and spreadsheet programs.  Data recorded in Binary format will require a translation program that utilizes the LORD ® ™...

  • Page 23: Sensor Measurements

    User Manual Sensor Measurements ™ The 3DM-GX4-45 block diagram (Figure 15 - 3DM-GX4-45™ Block Diagram ) describes its primary hardware components and internal configuration. Integrated Micro-Electro-Mechanical ™ System (MEMS) sensors within the 3DM - GX4 - 45 are collectively known as the Inertial Measurement Unit (IMU) and include tri-axial gyroscopes (gyros), tri-axial accelerometers, tri-axial magnetometers, and a pressure altimeter.

  • Page 24: Direct Sensor Measurements (Imu Outputs)

    ™ 3DM-GX4-45 Inertial Navigation System Sensor Measurements User Manual 4.1 Direct Sensor Measurements (IMU Outputs) The sensors in an Inertial Navigation System (INS), from which measurements for navigation and orientation are obtained, are collectively know as the Inertial Measurement Unit (IMU).
  • Page 25 Sensor Measurements User Manual ™ Table 4 - IMU Measurements lists the IMU measurements available for the 3DM-GX4-45 ™ Additional measurement units may be available in MIP  Monitor for some outputs however they are converted values and do not represent the actual sensor outputs. Only actual output units are listed.

  • Page 26: Global Positioning System (Gps) Outputs

    ™ 3DM-GX4-45 Inertial Navigation System Sensor Measurements User Manual 4.2 Global Positioning System (GPS) Outputs ™ The Global Positioning System (GPS) receiver in the 3DM - GX4- 45 uses its own GPS positioning engine to calculate a position, velocity, and time solution, and requires a minimum of four satellites.
  • Page 27 ™ 3DM-GX4-45 Inertial Navigation System Sensor Measurements User Manual Measurement Units Description position reported by GPS module only, degrees expressed in Latitude, Longitude, and Height (latitude, longitude) (LLH) with accuracy estimation. Height is Position (LLH) meters elevation or altitude relative to average sea...

  • Page 28: Computed Outputs (Estimation Filter)

    User Manual 4.3 Computed Outputs (Estimation Filter) ™ The computed outputs are measurements from the 3DM-GX4-45 IMU sensors and GPS receiver that are blended through an Extended Kalman Filter (EKF) algorithm. The Kalman Filter produces a better estimation of position, velocity, and attitude (PVA) outputs than can be achieved by the inertial sensors or the GPS individually.
  • Page 29 ™ 3DM-GX4-45 Inertial Navigation System Sensor Measurements User Manual Measurement Units Description indicates the current state of the EF, such Filter Status as running or initializing GPS time corresponding to the calculated GPS Time weeks & seconds filter solution estimated position based on combined...
  • Page 30 ™ 3DM-GX4-45 Inertial Navigation System Sensor Measurements User Manual Measurement Units Description one-sigma uncertainty reading available WMM (World Mag- WMM local magnitude, inclination and Gauss netic Model) declination based on GPS coordinates Pressure Altitude meters (altitude) altitude estimate from barometric pressure meters (altitude) altitude as derived from the U.S.

  • Page 31: Sensor Reference Frames

    ™ 3DM-GX4-45 Inertial Navigation System Sensor Measurements User Manual 4.4 Sensor Reference Frames 4.4.1 Geodetic Frame The World Geodetic System is the standard for cartography and navigation. The latest ™ revision, WGS84, is the reference coordinate system for GPS, and the 3DM- GX4-45 reports position using this coordinate frame.

  • Page 32: North East Down (Ned) Frame

    For most applications, this assumption is valid and provides a more intuitive reference frame for expressing velocity and attitude information than a global frame. ™ The 3DM-GX4-45 reports velocity in this frame and attitude with respect to this frame. Figure 20 -...

  • Page 33: Sensor Frame

    NED frame exactly, giving zero rotation. ™ The 3DM-GX4-45 reports acceleration, angular rate, delta-Theta, delta-velocity, inertial sensor biases and corrections, and GPS antenna offset error in this frame when no sensor-...

  • Page 34: Platform Frame

    User Manual 4.4.4 Platform Frame ™ The 3DM-GX4-45 includes the option to define an orientation transformation and offset distance from the sensor frame to a user-definable platform frame. This is useful when the sensor cannot be mounted in the same location or orientation as the desired reference point on the platform frame.
  • Page 35 ™ 3DM-GX4-45 Inertial Navigation System Sensor Measurements User Manual ™ In the MIP  Monitor software the transformation and offset settings are entered in the Settings > Device > Estimation Filter > Mounting > Mounting Orientation and Mounting Offset fields (Figure 23 - Platform Frame Settings).

  • Page 36: Performance Optimization

    ® ™ recommended. This can be accomplished using LORD MicroStrain Hard and Soft Iron ™ Calibration software. This software is included with the MIP  Monitor Software Suite...
  • Page 37 ™ 3DM-GX4-45 Inertial Navigation System Performance Optimization User Manual 3. The sensor should have automatically appeared in the sensor list (Figure 24 - Sensor Menu). If not, use the Refresh button to query it and then select the sensor. 4. Select the Arm Recording button next to Collect Data (Figure 25 - Collect Calibration Data).
  • Page 38 ™ 3DM-GX4-45 Inertial Navigation System Performance Optimization User Manual 6. Select the Spherical Fit or Ellipsoid Fit button, depending on the application. Spherical Fit is often the best fit for applications with calibration rotations restricted to a 2D plane. For example, a ground vehicle or a boat because it will not likely not be rotated on all three axis.

  • Page 39: Gyroscope Bias

    ™ 3DM-GX4-45 Inertial Navigation System Performance Optimization User Manual 5.2 Gyroscope Bias Gyroscope biases (offsets) can be zeroed out to set a baseline value for the static home position and conditions in the application. This should be done after sensor installation.

  • Page 40: Heading Drift And Compensation

    ™ 3DM-GX4-45 Inertial Navigation System Performance Optimization User Manual Heading Drift and Compensation There are four options for the heading reference source: GPS velocity, the magnetometer, an external reference, or none. If the setting is an external reference, the user has to provide a heading reference (for example, see GPS External Receiver on page...

  • Page 41: Angular Rate And Acceleration Limits

    5.7 GPS Parameters ™ The GPS receiver used in the 3DM-GX4-45 has a speed limitation of 500 meters/second in accordance with the United States International Treaty in Arms Regulation (ITAR) restrictions.

  • Page 42: Gps Antenna Offset

    GPS outage conditions will provide an indication of the estimation accuracy. 5.8 GPS Antenna Offset ™ GPS antenna offset is the distance of the antenna for the GPS receiver in the 3DM-GX4-45 Errors in this offset effects the accuracy of the EKF position, velocity and attitude solutions. The ™...

  • Page 43: Vehicle Dynamics Mode

     Monitor software this setting is found in the Settings > Device > Estimation Filter > EF Options > Vehicle Dynamics Mode menu (Figure 30 - Vehicle Dynamics Setting). ™ Refer to the 3DM-GX4-45 Data Communications Protocol (DCP) for more information about this setting. Figure 30 - Vehicle Dynamics Setting...

  • Page 44: Estimation Filter Operation

    (no translation or rotation between the two) they can be compensated for by performing ™ a hard iron and/or soft iron calibration of the magnetometers internal to the 3DM-GX4-45 see Magnetometer Calibration on page 36 ). The hard iron calibration compensates for magnetic effects that cause offsets in the magnetic field (additive effects).
  • Page 45 ™ state than either system individually. The 3DM-GX4-45 has a full-state dynamics model. The state propagation utilizes Newton’s and Euler’s equations of motion with the acceleration and angular rate treated as control inputs.

  • Page 46: Estimation Filter Convergence

    5.11.3 Output Uncertainty ™ The 3DM-GX4-45 estimation data set includes a filter status field that contains a set of status flags. These flags pertain to high covariance values for position, velocity, attitude, and inertial sensor parameters. These flags should be monitored and cross-check against the...

  • Page 47: Vibration Isolation

    5.13 IMU Sensor Calibration ™ All of the sensor internal to the 3DM-GX4-45 are calibrated when it is manufactured and the calibration values are saved in the device memory. With the exception of the magnetometer field calibration (...

  • Page 48: Sensor Installation

    ™ 3DM-GX4-45 Inertial Navigation System Sensor Installation User Manual Sensor Installation 6.1 Sensor Mounting ™ The 3DM- GX4- 45 sensor housing is rated for indoor use only, unless used inside of a protective enclosure.  When using the internal GPS receiver, the GPS antenna connector on the side of the sensor must be accessible.

  • Page 49: Gps Antenna Installation

    The GPS antenna cable is plugged into the non-magnetic SMA-to- MMCX adapter cable ™ ™ supplied with the 3DM-GX4-45 . The adapter cable is then plugged into the 3DM-GX4-45 housing (see Interface and Indicators on page 10). The GPS antenna provided with the starter...

  • Page 50: Oem System Integration

    ™ control systems that react to the sensor outputs. For these applications the 3DM-GX4-45 available as a stand-alone component with optional interface connectors. The communication protocol used for configuring and acquiring sensor data and estimations outputs is available for these applications as well.

  • Page 51: Packet Builder

    ™ To expedite program development, a packet builder tool is included in the MIP  Monitor ™ software. The packet builder allows users to send multiple packets to the 3DM-GX4-45 and view the resulting reply data. ™ ™ Applicable protocol structure and design is described 3DM-GX4-45  DCP Manual.

  • Page 52: Sensor Direct Mode

     Monitor. ™ When in Sensor Direct mode the 3DM-GX4-45 normal functionality is not available. The protocol commands used to interface with the IMU are a subset of the standard LORD ® ™ MicroStrain  Data Communications Protocol and are further described in LORD ®...

  • Page 53: Gps Direct Mode

    GPS Direct mode and is used to allow communication with the receiver through an external utility program available from the GPS receiver manufacturer (such as u- Blox) or by ® contacting LORD MicroStrain Technical Support (see Technical Support on page 65).

  • Page 54: Sensor Wiring

    ® Sensor power and serial communications cables are available from LORD MicroStrain come with the sensor starter kits. These cables will have the micro-DB9 connector on one end (to connect to the sensor) and either a standard DB9 on the other end (for RS232 communication) or a USB connector (for USB communications).

  • Page 55: Alternate Gps Equipment

    7.3 Alternate GPS Equipment ™ Other (external) GPS receivers, antennas and/or cables can be used with the 3DM-GX4-45 When using third party antennas the antenna cable length, antenna gain, and antenna power must be considered. For antennas with internal LNA (Low Noise Amplifiers) the power requirements should not have a minimum voltage below 3 volts and the current draw should not be over 20mA.

  • Page 56: Inertial Navigation System

    ™ 3DM-GX4-45 Inertial Navigation System OEM System Integration User Manual Figure 37 - GPS Source Select Figure 38 - External GPS Data...

  • Page 57: Sampling On Start-Up

    MIP  Monitor for data logging is not required. This functionality can also be embedded in user-designed applications by using the ® ™ corresponding LORD MicroStrain  Data Communications Protocol command ( Data Communications Protocol (DCP) on page 50 for more information). NOTE...

  • Page 58: Connecting To A Datalogger

    Many inertial applications incorporate dataloggers, of all different types, to collect and distribute sensor outputs. For more information and examples refer to the "Using Dataloggers with ® Inertial Sensors" Technical Notes on the LORD MicroStrain website, or contact LORD ®...

  • Page 59: Troubleshooting

    ™ 3DM-GX4-45 Inertial Navigation System Troubleshooting User Manual Troubleshooting 8.1 Troubleshooting Guide...
  • Page 60 (See Technical Support on page 65). 1.5 sensor is damaged If all power settings and connections have been verified, and ® the sensor is still unresponsive, contact LORD MicroStrain Technical Support (See Technical Support on page 65). ™ 2.1 sensor not found in MIP  Monitor...
  • Page 61 Verify all connections, power, and settings.  If available, try installing an alternate cable or sensor one at a time to see if the faulty device can be identified.  If no conclusion can be determined, or to send a device in for repair, contact LORD ® MicroStrain...
  • Page 62 CSV and Binary output formats. If the data is recorded in Binary format it will require a translation program that utilizes ® ™ the LORD MicroStrain  Data Communications Protocol to make it human readable. 3.6 sensor has been magnetized Contact or close proximity with magnets may disrupt the sensor operation and cause magnetization of internal components, which can affect magnetometer performance.
  • Page 63 ™ 3DM-GX4-45 Inertial Navigation System Troubleshooting User Manual Problem Possible cause and recommended solution offset or drift on the IMU sensor outputs. Sensor damage can occur as a result of excessive g-force other conditions outside of its operating specifications.

  • Page 64: Repair And Calibration

    ® have the LORD MicroStrain model number and serial number, as well as your name, organization, shipping address, telephone number, and email.  Normal turn-around for RMA items is 7 days from receipt of item by LORD ® MicroStrain Warranty Repairs ®...

  • Page 65: Technical Support

    Troubleshooting User Manual 8.3 Technical Support ® There are many resources for product support found on the LORD MicroStrain website including technical notes, FAQs, and product manuals. http://www.microstrain.com/support_overview.aspx For further assistance our technical support engineers are available to help with technical and applications questions.

  • Page 66: Maintenance

    ™ 3DM-GX4-45 Inertial Navigation System Maintenance User Manual Maintenance ™ There are no user-serviceable parts on the 3DM-GX4-45 . Removing the device cover or disassembling in any way will void the product warranty.

  • Page 67: Parts And Configurations

    For the most current product information, custom, and OEM options not listed below, refer to ® ® the LORD MicroStrain website or contact the LORD MicroStrain Sales Department. Table 7 - Model Numbers describes the standard models available at the time this manual was published.
  • Page 68 3DM-GX4-15 Starter Kit (USB, +/-5g, 300°/sec) 6233-4241 3DM-GX4-25 Starter Kit (RS232, +/-5g, 300°/sec) 6234-4221 3DM-GX4-25 Starter Kit (USB, +/-5g, 300°/sec) 6234-4241 3DM-GX4-45 Starter Kit (RS232, +/-5g, 300°/sec) 6236-4221 3DM-GX4-45 Starter Kit (USB, +/-5g, 300°/sec) 6236-4241 Table 8 - Example Part Numbers...

  • Page 69: Accessories

    The following parts are available for use with the 3DM-GX4 and some are included in sensor ® starter kits. For the most current product information refer to the LORD MicroStrain website or contact the Sales Department. See Sales Support on page ®...

  • Page 70: Sales Support

    Parts and Configurations User Manual 10.3 Sales Support ® Products can be ordered directly from the LORD MicroStrain website by navigating to the product page and using the Buy feature.  http://www.microstrain.com/inertial For further assistance, our sales team is available to help with product selection, ordering options, and questions.

  • Page 71: Specifications

    ™ 3DM-GX4-45 Inertial Navigation System Specifications User Manual Specifications General Triaxial accelerometer, triaxial gyroscope, triaxial Integrated sensors magnetometer, temperature sensors, pressure altimeter and GPS receiver Inertial Measurement Unit (IMU) outputs: acceleration, angular rate, magnetic field , ambient pressure, deltaTheta, deltaVelocity...
  • Page 72 ™ 3DM-GX4-45 Inertial Navigation System Specifications User Manual Computed Outputs Position accuracy ±2.5 m RMS horizontal, ± 5 m RMS vertical (typ) Velocity accuracy ±0.1 m/s RMS (typ) EKF outputs: ±0.25° RMS roll & pitch, ±0.8° RMS heading (typ) Attitude accuracy CF outputs: ±0.5°...

  • Page 73: Safety Information

    This section provides a summary of general safety precautions that must be understood and ® applied during operation and maintenance of components in the LORD MicroStrain Inertial Sensor Products.  Throughout the manual, ANSI Z535 standard safety symbols are used to indicate a process or component that requires cautionary measures.

  • Page 74: Addendum

    User Manual Addendum 13.1 Reference Diagrams The diagrams in this section are to intended to aid in product installation and troubleshooting. ® For more information contact LORD MicroStrain Technical Support (see Technical Support on page 65). 13.1.1 Sensor Dimensions and Origin This diagram describes the sensor physical specification including the measurement point of origin.

  • Page 75: Gps Antenna Specifications

    ™ 3DM-GX4-45 Inertial Navigation System Addendum User Manual 13.1.2 GPS Antenna Specifications ™ These specifications describe the GPS antenna included in the 3DM-GX4 starter kit. Physical Specifications Construction Polycarbonate radome enclosure with die cast shell Dimensions 58 mm x 48 mm x 15 mm...

  • Page 76: Power Supply Specifications (Rs232 Kits Only)

    ™ 3DM-GX4-45 Inertial Navigation System Addendum User Manual 13.1.3 Power Supply Specifications (RS232 kits only) The power supply is only required for the RS232 devices. These specifications describe the ™ power supply included in the 3DM-GX4 starter kit. Operating Parameters...

  • Page 77: Communication And Power Cables

    ™ 3DM-GX4-45 Inertial Navigation System Addendum User Manual 13.1.4 Communication and Power Cables ™ These diagrams describe the cables included in the 3DM-GX4 starter kits. Only one is included, depending on the type of kit ordered. Figure 42 - Communications and power cable (RS232 Kits, PN: 4005-0037)

  • Page 78: Reference Documents

    Connecter interface cable (sold separately, PN: 6224-0100) 13.2 Reference Documents ® Many references are available on the LORD MicroStrain website including product user manuals, technical notes, and quick start guides.  These documents are continuously updated and may provide more accurate information than printed or file copies. ...

  • Page 79: Glossary

    ™ 3DM-GX4-45 Inertial Navigation System Addendum User Manual 13.3 Glossary A/D Value The digital representation of analog voltages in an analog-to-digital (A/D) conversion. The accuracy of the conversion is dependent on the resolution of the system electronics. Higher res- olution produces a more accurate conversion.
  • Page 80 ™ 3DM-GX4-45 Inertial Navigation System Addendum User Manual API (Applications Programming Interface) A library and/or template for a computer program that specifies how components will work together to form a user application. For example, how hardware will be accessed and what data structures and variables will be used.
  • Page 81 ™ 3DM-GX4-45 Inertial Navigation System Addendum User Manual Data Acquisition The process of collecting data from sensors and other devices Data Logging The process of saving acquired data to the system memory, either locally on the device, or remotely on the host computer.
  • Page 82 ™ 3DM-GX4-45 Inertial Navigation System Addendum User Manual GPS (Global Positioning System) A network of space based statellites use to triangulate position co-ordinates and provide time information for navigational purposes. Gyroscope A device used to sense angular movements such as rotation.
  • Page 83 ™ 3DM-GX4-45 Inertial Navigation System Addendum User Manual LOS (Line of Sight) Line of Sight is an acronym used in wireless communications that describes the ideal condition between transmitting and receiving devices in a wireless network.  As stated, it means they are in view of each other with no obstructions.
  • Page 84 ™ 3DM-GX4-45 Inertial Navigation System Addendum User Manual Position The spatial location of an object Position Velcoity and Attitute Quaternion Mathematical notation for representing orientation and rotation of objects in three dimensions with respect to the fixed earth coordinate quaternion. Quaternions convert the axis–angle rep- resentation of the object into four numbers and to apply the corresponding rotation to a position vector representing a point relative to the origin.
  • Page 85 ™ 3DM-GX4-45 Inertial Navigation System Addendum User Manual Sampling Rate The frequency of sampling Sensor A device that physically or chemically reacts to environmental forces and conditions and pro- duces a predictable electrical signal as a result Sigma In statistics, sigma is the standard deviation from the mean of a data set.
  • Page 86 ™ 3DM-GX4-45 Inertial Navigation System Addendum User Manual In navigation yaw is what occurs rotational force is applied at a distance forward or aft from the center of gravity of the platform, causing it to move around the center axis of a sensor or plat-...

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