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CSI Wireless SX-1 Integrator's Manual

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SX-1
Integrator's Manual
Part Number 875-0109-002
Date:
January 2004

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  • Page 1 SX-1 Integrator’s Manual Part Number 875-0109-002 Date: January 2004...
  • Page 2 Copyright Notice © Copyright 2004 CSI Wireless Inc. All rights reserved. No part of this manual may be stored in a retrieval system, transmitted, or reproduced by any means, including, but not limited to photocopy, photograph, digitizing, or otherwise, without the prior written permission from CSI Wireless Inc.
  • Page 3 Purchaser’s Exclusive Remedy The end purchaser’s exclusive remedy under this warranty shall be limited to the repair or replacement, at the option of CSI Wireless, of any defective Products or components thereof. The end user shall notify CSI Wireless or a CSI Wireless approved service center immediately of any claimed defect.
  • Page 4 Products are not intended for primary navigation or for use in safety of life applications. The potential accuracy of Products as stated in CSI Wireless literature and/or Product specifications serves to provide only an estimate of achievable accuracy based on: •...
  • Page 5 Obtaining Warranty Service In order to obtain warranty service, the end purchaser must bring the Product to a CSI Wireless approved dealer, along with the end purchaser’s proof of purchase. For any questions regarding warranty service or to obtain information regarding the location of any of CSI Wireless’s dealers, contact CSI Wireless at the following address: CSI Wireless Inc.
  • Page 6 SX-1 Evaluation Integrator’s Manual...

  • Page 7: Table Of Contents

    Notes, Cautions, and Warnings................xxvi Quick Start ........................1 Receiving Your Shipment..................1 Unpacking Your Vector Sensor System............. 1 Cable Connections....................2 Configuring the SX-1 Evaluation................. 3 NMEA 0183 Message Interface................4 Binary Message Interface..................4 SLXMon........................4 Default Parameters ....................5 Pin-Outs........................
  • Page 8 SX-1 Evaluation System....................21 System Parts List....................21 Cable Interface......................22 3.2.1 Routing and Securing the Cable ............22 Environmental Requirements................23 Power Requirements ...................23 Antenna Placement....................24 Powering the SX-1 Evaluation System .............24 Serial Port Interface.....................25 Factory Default Parameters................27 LED Indicators......................29 Evaluation Motherboard ....................32 Schematics......................32 Layout........................33 viii...
  • Page 9 1 PPS Timing Signal................48 5.6.6 Event Marker Input................49 5.6.7 Grounds....................49 5.6.8 Misc. Pins....................49 Shielding.........................49 SX-1 Operation ......................51 Powering the SX-1 Evaluation System .............51 Communicating with the SX-1 Evaluation System.........51 6.2.1 NMEA 0183 Interface................52 6.2.2 Binary Interface..................53 6.2.3 RTCM SC-104 Protocol................53 Configuring the SX-1...................55...
  • Page 10 Firmware........................55 Configuring the Data Message Output............56 6.5.1 This Port and the Other Port..............56 Saving the SX-1 Configuration ................57 Using Port C for RTCM Input................57 SLXMon Utility ........................59 Connecting to SLXMon..................60 View SLX Diagnostics With SLXMon...............62 NMEA 0183 Messages....................68 NMEA Message Elements ...................68 General Commands.....................69...
  • Page 11 $JRAD,1,lat,lon,alt..................94 8.5.4 $JRAD,2....................95 8.5.5 $JRAD,3....................96 Data Messages ......................97 8.6.1 GGA Data Message................98 8.6.2 GLL Data Message.................99 8.6.3 GSA Data Message................100 8.6.4 GST Data Message................101 8.6.5 GSV Data Message................102 8.6.6 RMC Data Message................103 8.6.7 RRE Data Message................104 SX-1 Evaluation Integrator’s Manual...
  • Page 12 Bin 98.....................121 9.1.10 Bin 99.....................122 Frequently Asked Questions..................125 10.1 Integration ......................125 10.2 General ........................126 10.3 Support and Repairs..................128 10.4 Troubleshooting....................129 10.5 Power, Communication, and Configuration ..........130 10.6 GPS Reception and Performance..............132 10.7 SBAS Reception and Performance..............133 SX-1 Evaluation Integrator’s Manual...
  • Page 13 10.8 e-Dif........................134 10.9 External Corrections..................135 10.10 Installation.....................135 Troubleshooting.......................137 Appendix A - Specifications....................139 Appendix B - Interface......................143 Appendix C – Surface Mount Template................149 Appendix – D Resources.....................169 Index .............................172 SX-1 Evaluation Integrator’s Manual xiii...
  • Page 14 SX-1 Evaluation Integrator’s Manual...

  • Page 15: List Of Figures

    Figure 1-1 Cable Interface......................3 Figure 2-1 e-Dif Error Drift....................15 Figure 3-1 Cable Interface......................22 Figure 3-2 DB9 Socket Numbering ..................27 Figure 3-3 SX-1 Evaluation Front Panel ................30 Figure 4-1 Evaluation Motherboard ..................34 Figure 4-2 Evaluation Motherboard LEDs................35 Figure 4-3 Antenna Voltage Jumper..................37 Figure 4-4 1 PPS and Event Marker Jumper ...............38...
  • Page 16 Figure C-4 Extrapolated WAAS Inonspheric Correction Map........167 Figure C-5 Broadcast EGNOS Inonspheric Correction Map ........168 Figure C-6 Extrapolated EGNOS Inonspheric Correction Map........168 SX-1 Evaluation Integrator’s Manual...

  • Page 17: List Of Tables

    Table 3-6 Default Port Settings.....................28 Table 3-7 Default GPS NMEA Message Output..............28 Table 3-8 Default Parameters....................28 Table 3-9 LED Indicator Definition ..................29 Table 5-1 SX-1 Specifications....................40 Table 5-2 SX-1 Connectors....................43 Table 5-3 SX-1 Pin-out......................45 Table 8-1 NMEA Message Elements..................68 Table 8-2 General Commands....................69 Table 8-3 GPS Commands.....................84...
  • Page 18 Table 9-6 Bin 94 Message....................117 Table 9-7 Bin 95 Message....................118 Table 9-8 Bin 96 Message....................119 Table 9-9 Bin 97 Message....................120 Table 9-10 Bin 98 Message....................121 Table 9-11 Bin 99 Message....................122 Table 11-1 Troubleshooting....................137 Table A-1 SX-1 Evaluation Enclosure Specifications............139 xviii SX-1 Evaluation Integrator’s Manual...
  • Page 19 Table A-2 SX-1 Module Specifications................140 SX-1 Evaluation Integrator’s Manual...
  • Page 20 SX-1 Evaluation Integrator’s Manual...

  • Page 21: Preface

    Additionally, this presentation of the SX-1 module may give you ideas for the design of your product using the SX-1 as a positioning sensor. SX-1 Evaluation Integrator’s Manual...
  • Page 22 The SX-1 GPS engine is a low-level module intended for custom integration with the following general integration requirements: • Regulated power supply input (3.3 VDC ± 5%) capable of sourcing mA on startup and 210 mA continuous • Low-level serial port communications (3.3 V TTL) •...

  • Page 23: Organization

    Chapter 1: Quick Start - provides information to help you get your system running quickly. Chapter 2: Introduction - introduces you to the SX-1 and some of its main features. Chapter 3: SX-1 Evaluation System- introduces you to the sample SX-1 integration that we provide you for evaluating the SX-1.

  • Page 24: Customer Service

    If you encounter problems during the installation or operation of this product, or cannot find the information you need, please contact your dealer, or CSI Wireless Customer Service. The contact numbers and e- mail address for CSI Wireless Customer Service are:...

  • Page 25: World Wide Web Site

    When providing the RMA number, CSI Wireless will provide you with shipping instructions to assist you in returning the equipment. World Wide Web Site CSI Wireless maintains a World Wide Web home page at the following address: www.csi-wireless.com A corporate profile, product information, application news, GPS and DGPS literature, beacon coverage information, and software are available at this site.

  • Page 26: Notes, Cautions, And Warnings

    Notes, Cautions, and Warnings Notes, Cautions, and Warnings stress important information regarding the installation, configuration, and operation of the SX-1 Evaluation system. Note - Notes outline important information of a general nature. Cautions - Cautions inform of possible sources of difficulty or situations that may cause damage to the product.

  • Page 27: Quick Start

    1. Quick Start The purpose of this chapter is to help you get your SX-1 Evaluation system running quickly. This chapter is not intended to replace the balance of this reference manual and it assumes that you have a reasonable amount of knowledge with installation and operation of GPS navigation systems.

  • Page 28: Cable Connections

    SX-1, labelled ‘PORT A’, ‘PORT B’, and ‘PORT C’. In addition to the power, RF input, and serial ports, there is a chassis ground connection present, labelled ‘GROUND’.

  • Page 29: Configuring The Sx-1 Evaluation

    Figure 1-1 Cable Interface 1.4 Configuring the SX-1 Evaluation The SX-1 has two primary communication ports referred to as Port A and Port B. Both are fully independent and may have different message output at different rates. Each of these ports may be configured for external...

  • Page 30: Nmea 0183 Message Interface

    NMEA interface in detail. 1.6 Binary Message Interface In addition to the NMEA interface, the SX-1 module also supports a selection of binary messages. There is a wider array of information available through the binary messages, plus binary messages are inherently more efficient with data.

  • Page 31: Default Parameters

    SX-1 Evaluation System, as integrated. The parameters for the SX-1 module are virtually the same, however, the SX-1 uses a 3.3 V TTL signal level for serial communication. Table 1-1 Default Applications Application...

  • Page 32: Pin-Outs

    5° 1.9 Pin-Outs The following tables detail the pin-out of the three serial ports of the Evaluation Enclosure. The pin-out of the SX-1 also differs from that of the Evaluation Enclosure. Table 1-5 Port A Pin-out, RS-232C Interface Level Signal...

  • Page 33: Table 1-7 Port C Pin-Out, Rs-232C Interface Level

    Table 1-7 Port C Port Pin-out, RS-232C Interface Level Signal Description NMEA 0183 NMEA 0183 and RTCM Input Sig. Ground Signal Return SX-1 Evaluation Integrator’s Manual...
  • Page 34 SX-1 Evaluation Integrator’s Manual...

  • Page 35: Introduction

    (8-N- 1). Additionally, since the SX-1 is a low-level module, it will need to receive corrections at a 3.3 V TTL signal level.

  • Page 36: Satellite Tracking

    Since the SX-1 will be used in the real world, blockage of the line of sight to SBAS satellites is often inevitable. The COAST function provides solace from obstruction of SBAS services for up to 30 to 40 minutes, depending on the amount of tolerable performance drift.

  • Page 37: Update Rates

    2.1.3 Update Rates The update rate of each NMEA and binary message of the SX-1 can be set independently with a maximum that is dependant upon the message type. Some messages have a 1 Hz maximum, for example, while others are 5 Hz.

  • Page 38: Sbas Performance

    GPS ionospheric model and the ionospheric SBAS map. To minimize the impact of this issue on your use of the SX-1, we may wish to wait up to five minutes before using the SX-1 or issue the $JQUERY,GUIDE<CR><LF>...

  • Page 39: Coast™ Technology

    COAST technology provides more consistent positioning during periods when signal loss occurs, thus bridging the gap to when the signal is reacquired. This means that the SX-1 module is more tolerant than competing products to loss of SBAS or externally input RTCM SC-104 corrections.
  • Page 40 Figure 2-1 displays the static positioning error of e-Dif, while it is allowed to age for 14 consecutive cycles of 30 minutes. The top (red) line indicates the age of the differential corrections. The SX-1 computes a new set of corrections using e-Dif during the calibration at the beginning of each hour and modifies these corrections according to its models.

  • Page 41: E-Dif Operation

    2.5 e-Dif Operation Operation of the SX-1 unit with the optional e-Dif application requires the sending of NMEA commands. These commands may be automatically issued through customized software or a simple terminal interface running on a PDA or data logger.

  • Page 42: Start-Up

    2.5.1 Start-up When you turn the SX-1 on with the e-Dif application running, it will require a minimum of a few minutes to gather enough satellite tracking information to model the errors for the future (up to 10 minutes may be required depending on your environment).

  • Page 43: Post Processing

    Our translator is available at the following Web site: www.satloc.com/rinex.stm Note - To assist you in your integration of the SX-1, we can equip you with some code snippets to help you incorporate support for SX-1 Evaluation Integrator’s Manual...

  • Page 44: Evaluating Sx-1 Performance

    As mentioned earlier, CSI Wireless evaluates performance of the SX-1 module with the objective of determining best-case performance in a real- world environment. Our static testing has shown that the SX-1 achieves a performance better than one meter 95% of the time.

  • Page 45: Table 2-2 Horizontal Accuracy Statistic Conversions

    When testing dynamically, a much more accurate reference would need to be used, such as an RTK system so that a ‘truth’ position per epoch is available. SX-1 Evaluation Integrator’s Manual...
  • Page 46 If you require assistance in developing a test setup or procedure for evaluating the SX-1, please contact CSI Wireless. SX-1 Evaluation Integrator’s Manual...

  • Page 47: Evaluation System

    The following two chapters break this integrated product up into two primary parts: the Evaluation Motherboard and then the SX-1 module. Both of these chapters provide information on their respective details. The SX-1 Evaluation system is composed primary of the following subassemblies: •...

  • Page 48: Cable Interface

    3.2 Cable Interface The SX-1 Evaluation enclosure requires power, data, and antenna cable interfaces. The following figure shows the various connections located on the rear panel of the SX-1 Evaluation enclosure. Figure 3-1 Cable Interface 3.2.1 Routing and Securing the Cable When choosing a route for Evaluation system cables.

  • Page 49: Environmental Requirements

    The Evaluation Enclosure and SX-1 module are designed to be stored between -40°C and +85°C. The operating temperature range is -30°C and +70°C. Both the Enclosure with internal motherboard the SX-1 module are specified to operate with humidity up to 95% non-condensing.

  • Page 50: Antenna Placement

    SX-1 is not compromised, giving you the best performance possible. • Make sure that there is sufficient length of the antenna extension cable available in order to be able to connect it to the SX-1 Evaluation enclosure Do not locate the antenna where environmental conditions exceed those specified in Section 3.3.

  • Page 51: Serial Port Interface

    A 1.0 A fast-blow fuse, situated in-line of the power input of the extension cable and protects the SX-1 receiver from power surges. The fuse container should remain accessible after installation.

  • Page 52: Table 3-2 Port A Pin-Out, Rs-232C Interface Level

    Signal Return Note – Port C is to be used exclusively for external RTCM input to the SX-1 from a source such as a beacon receiver. This port operates permanently at 9600 baud with an 8 data bit, no parity, and 1 stop bit configuration.

  • Page 53: Factory Default Parameters

    Figure 3-2 DB9 Socket Numbering Refer to Appendix B for further interfacing information. Note - For successful communications, the baud rate of the SX-1 serial ports must be set to match that of the devices to which they are connected. Chapter 8 describes the baud rate change command.

  • Page 54: Table 3-6 Default Port Settings

    9600 None RS-232C Note - The RS-232C interface level is that of the Evaluation Motherboard and not the SX-1, which uses a TTL level. Port C operates permanently at 9600 baud. Table 3-7 Default GPS NMEA Message Output Port GPS NMEA Messages...

  • Page 55: Led Indicators

    Yellow Differential lock indicator – this indicator will illuminate continuously when the SX-1 has achieved a solid SBAS lock with better than a 150 bit error rate (BER) or when it is successfully receiving externally input RTCM corrections. If the SBAS BER is higher than 150 but the receiver is still locked, this LED will blink, showing that lock is marginal.

  • Page 56: Figure 3-3 Sx-1 Evaluation Front Panel

    GPS lock, Differential lock, and the DGPS position LEDs illuminate in sequence a few times and then go out. When the SX-1 acquires a GPS lock, the yellow GPS lock LED will illuminate solidly. Similarly, the differential LED will illuminate when the SBAS demodulator has acquired lock, or externally input corrections are being successfully received.
  • Page 57 SX-1 Evaluation Integrator’s Manual...

  • Page 58: Evaluation Motherboard

    4.1 Schematics With the purchase of the SX-1 Evaluation system, and in addition to the information provided in this Integrator’s Manual, we will make available to you the Evaluation Motherboard schematics through e-mail, to assist your integration efforts.

  • Page 59: Layout

    You will notice from the examination of the Evaluation Motherboard layout the following: • The SX-1 is mounted such that the motherboard’s P201 RF input MCX connector and the J400 signal interface header are used by the SX-1 • The input power applied to the Evaluation Motherboard (9 to 38 VDC) is applied at connector P202 •...

  • Page 60: Figure 4-1 Evaluation Motherboard

    The following figure shows the general layout of the SX-1 Evaluation Motherboard. Figure 4-1 Evaluation Motherboard SX-1 Evaluation Integrator’s Manual...

  • Page 61: Leds

    4.3 LEDs The SX-1 Evaluation Motherboard has five through-hole mounted LEDs for indication of system status as mentioned in the previous chapter. The onboard SX-1 module provides these signals to the motherboard’s LEDs. The following figure displays the location of the status LEDs on the motherboard.

  • Page 62: Antenna Voltage

    – essentially 0 VDC across the RF connector), or you can apply the voltage to the P203 connector beside the JP202 jumper. The latter is the easier of the two options and has less risk of damaging the SX-1 with DC voltage.

  • Page 63: 1Pps Output Signal

    1 PPS signal by looking at the 1 PPS LED when the SX-1 is computing a valid position. If you wish to make use of the signal outside of viewing the LED on the motherboard, you will need to change the position of the JP300 from its default ‘PB.’...

  • Page 64: Event Marker Input Signal

    4.6 Event Marker Input Signal The Event Marker input signal is used to interrupt the operations of the SX-1 to force a solution at that instant. The Evaluation Motherboard has a switch present, labelled SW300 that allows you to test this feature. If you...
  • Page 65 SX-1 Evaluation Integrator’s Manual...

  • Page 66: Module

    Ultimately, once you have completed your evaluation of the SX-1 within the Evaluation system, you will need to begin with the actual integration of the SX-1 module. This chapter describes the various details of the SX-1 module itself, apart from the Evaluation Motherboard.

  • Page 67: Mechanical Layout

    Environmental Specifications Item Specification Storage temperature -40°C to 85°C Operating temperature -30°C to 70°C Humidity 95% Non-Condensing 5.2 SX-1 Mechanical Layout The following figure shows the mechanical layout for the SX-1 module. All dimensions are in inches. SX-1 Evaluation Integrator’s Manual...

  • Page 68: Connectors

    .180 Figure 5-1 SX-1 Mechanical Layout 5.3 Connectors The following table details the connectors used by the SX-1 module. We have also provided information on the mating connectors used by the Evaluation Motherboard. Since your requirements may be different than those of the Evaluation Motherboard, you are free to choose a different, compatible connector.

  • Page 69: Mounting

    (Samtec: FTSH-117-01-L- (Samtec: FLE-117-01-G-DV) 5.4 SX-1 Mounting There are two methods of mounting the SX-1 module. The first is the most cost-effective method since it does not use cable assemblies to interface the module to the integration. Similar to the Evaluation Motherboard, we recommend that you place an RF connector, header connector, and mounting holes on your motherboard.

  • Page 70: Pin-Out

    0.125”. 5.5 SX-1 Pin-out The SX-1 module uses a 34-pin (17 pins by 2 rows) header connector for interfacing to power, communications, and other signals. You can identify the first pin of this connector by a small triangular corner on the silk- screen of the header connector footprint.

  • Page 71: Table 5-3 Sx-1 Pin-Out

    Table 5-3 SX-1 Pin-out Signal and Description Signal and Description Power input (3.3 VDC ±5%) Differential lock indicator (1 mA max, active low, 3.3 VDC – optional connection) Power in (3.3 VDC ±5%) DGPS position indicator (1 mA max, active low, 3.3 VDC – optional...

  • Page 72: Signals

    Further, you may connect the device on Port A directly to the device on Port B using a derivative of this same command. As the SX-1 serial ports are a 3.3 V TTL level, you may have to translate this level in order to interface to other devices based upon your product requirements.

  • Page 73: Communication Port C

    Please refer to the Pin-out table of the SX-1 for their pin number. Please note, however, that each of these signal pins can offer only 1 mA of current and are active low. Since 1...

  • Page 74: Pps Timing Signal

    The following figure shows SMT LEDs present on the SX-1 module. Figure 5-2 SX-1 Surface Mounted LEDs 5.6.5 1 PPS Timing Signal The one pulse per second (1 PPS) timing signal is used in applications where devices require time synchronization. This signal output is typical of most GPS modules and is not an obligatory feature.

  • Page 75: Event Marker Input

    Typically, the SX-1 does not require shielding for the sake of improving immunity to RF noise incident upon the board and it’s various devices. You may, however, wish to shield the SX-1 from the rest of the integration if you find that it interferes with other devices or systems.
  • Page 76 If you are designing a smart antenna based upon the SX-1 (the SX-1 and the GPS antenna in close proximity), you will likely want to shield the SX-1 so that it does not interfere with the incoming GPS signals to the antenna.

  • Page 77: Operation

    When installed such that the SX-1 Evaluation system has an unobstructed view of the sky, the SX-1 will provide a position quickly, within approximately 60 seconds. SBAS lock requires approximately 30 seconds to acquire.

  • Page 78: Nmea 0183 Interface

    Note - If you require different data types to be output from the SX-1 simultaneously (such as NMEA and binary or NMEA and RTCM), ensure that the software used for logging and processing of the data has been designed to correctly parse the different data types from the single stream of data.

  • Page 79: Binary Interface

    The SX-1 supports a variety standard and proprietary NMEA messages. These messages are used to configure the SX-1 and also contain the required information from the SX-1. You may configure a selection of NMEA 0183 data messages on one port at various update rates (each message has a maximum update rate) and a different selection of NMEA 0183 messages with different rates on the other port.
  • Page 80 RTCM has various levels of detail, however the highest level is the message. RTCM defines numerous messages that contain specific information. The SX-1 module processes the C/A code and does not support more advanced methods of differential positioning, such as real-time kinematic (RTK) that uses different RTCM message types.

  • Page 81: Configuring The Sx-1

    • Setting the satellite elevation angle cut-off mask 6.4 Firmware The software that runs the SX-1 is often referred to as firmware since it operates at a low level. There are two types of firmware within the SX-1 for the on-board digital signal processor (DSP) and the ARM processor.

  • Page 82: Configuring The Data Message Output

    ‘Other’ port. For example, if you are communicating with the SX-1 Port B, and wish to turn the GPGGA message on at an update rate of 5 Hz on Port A, the following command would be used.

  • Page 83: Saving The Sx-1 Configuration

    C provides this functionality although it’s been fixed to operate at a baud rate of 9600 (8 data bits, no parity, and 1 stop bit – 8-N-1). To use Port C of the SX-1 for correction input you must set the SX-1 to operate in beacon differential mode using the following command: $JDIFF,BEACON<CR><LF>...
  • Page 84 • Type 16 To return to using SBAS as the correction source, send the following command to the SX-1: $JDIFF,WAAS<CR><LF> You will find detailed information on NMEA messages supported by the SX-1 in Chapter 8 NMEA 0183 Messages. SX-1 Evaluation Integrator’s Manual...

  • Page 85: Slxmon Utility

    SLXMon is a freely available utility designed for use with CSI Wireless SLX and SX-1 based products. As this utility was not designed specifically for the SX-1 alone, it supports features not offered by the SX-1, such as tracking of the OmniSTAR differential service and display of our Vector product’s true heading, however, the interface may be used for all I/O...

  • Page 86: Connecting To Slxmon

    Open Connection – Click this button after you start the program. Make sure Port A or B from your SX-1 Evaluation system is connected to the serial port of your computer and that the receiver is powered on. SX-1 Evaluation Integrator’s Manual...

  • Page 87: Figure 7-2 Communication Port Settings

    If the ‘Not Connected’ message is never replaced, check that you are using the correct baud rate and that your connection to the computer’s Com Port is not at fault. Also check the power LED of the SX-1 Evaluation system to confirm that it is receiving 9 – 38 VDC power input.

  • Page 88: View Slx Diagnostics With Slxmon

    The buttons along the top of the window are used to open up windows in SLXMon. Using the menu above the button, you can also open up these windows. The primary windows are follow: View GPS Solution – Click this button to view the GPS Solution window. SX-1 Evaluation Integrator’s Manual...

  • Page 89: Figure 7-5 Gps Solution Window

    If you see any of these messages, except No Fix, then you are receiving GPS data. The SX-1 needs to find and use at least 4 satellites to receive 3- D position. Ideally, you should see 3-D DIFF, which means you have 3-D GPS and a differential solution fix.

  • Page 90: Figure 7-6 Channel Tracking Status

    – The Channel Number will turn Green when a satellite has full lock and is being used by the SX-1 to determine the position of your antenna. The number of channels with Green numbers is the same as the number of satellites used.

  • Page 91: Figure 7-7 Slx Monitor Window

    – This is the Elevation of the satellite in degrees above the horizon. By default, the SX-1 will ignore any satellites lower than 5 degrees above the horizon. This can be changed by setting the Elevation Mask with the $JMASK command as described later in this manual. The SX-1is more precise when it has more than 4 satellites widely spread across the sky at various elevations.

  • Page 92: Figure 7-8 L-Band Status Window

    This window emulates the LED status lights on the SX-1receiver. It also works as a test by reporting all errors the program detects while the SX- 1is running. Use this window as a quick reference to see if the SX-1 is operating correctly. If the colored rectangle labeled Monitor Status is green, then your SX-1 is operating correctly and has good performance.
  • Page 93 DGPS Valid Data Use ARMInitFreqOffset Use ARMInitFreqOffset DGPS solution DGPS solution DGPS solution is Good DGPS solution is Good Not Used ARM controls yellow LED 2 (if applicable) Not Used ARM command for yellow LED 2 (if applicable) SX-1 Evaluation Integrator’s Manual...

  • Page 94: Nmea 0183 Messages

    8. NMEA 0183 Messages The SX-1 GPS module supports a selection of NMEA 0183 and proprietary binary messages. This chapter identifies the selection of standard and proprietary NMEA 0183 messages for the SX-1 receiver. The following chapter describes the binary software interface in detail.

  • Page 95: General Commands

    SBAS signal more quickly upon start-up. This is not normally needed. $JQUERY,GUIDE This command is used to poll the SX-1 for its opinion on whether or not it is providing suitable accuracy after the both SBAS and GPS have been acquired...

  • Page 96: Jasc,D1

    RD1 message on the other port. 8.2.2 $JAIR This command allows you to place the SX-1 GPS engine within the SX- 1into AIR mode, where the receiver is optimized for the high dynamic environment associated with airborne platforms.

  • Page 97: Jasc,Virtual

    For example, if RTCM is input on Port B, this data will correct the SX-1position and also be output through Port A. The SX-1 acts as a pass- through for the RTCM data. Either port may be configured to accept RTCM data input and this command then allows the opposite port to output the RTCM data.

  • Page 98: Jalt

    $> 8.2.4 $JALT This command turns altitude aiding on or off for the SX-1 module. When set to on, altitude aiding uses a fixed altitude instead of using one satellite’s observations to calculate the altitude. The advantage of this feature, when operating in an application where a fixed altitude is acceptable, is that the extra satellite’s observations can be used to betterment of the latitude,...

  • Page 99: Jlimit

    $JSHOW command provides this information. 8.2.6 $JAPP This command allows you to request the SX-1 for the currently installed applications and to choose which application to use. The SX-1 by default comes pre-installed with WAAS (SBAS) with a second, empty application.
  • Page 100 AUTODIF (e-Dif) For the sake of the application names, the SBAS application is referred to as WAAS by the SX-1’s internal software. To change from the current application to the other application (when a two applications are present), issue the following command: $JAPP,OTHER<CR><LF>...

  • Page 101: Jbaud

    Note – Other derivatives of the $JAPP command are the $JAPP,1<CR><LF> and $JAPP,2<CR><LF> commands that can be used to set the SX-1 to use the first and second application. It’s best to follow up the sending of these commands with a $JAPP query to see which application is 1 or 2.

  • Page 102: Jconn

    8.2.8 $JCONN This command is used to create a virtual circuit between the A and B port, if needed. This allows you to through the SX-1 to the device on the opposite port. The virtual circuit command has the following form: $JCONN,p<CR><LF>...

  • Page 103: Jpos

    In order for the SX-1 to operate in autonomous mode, the NONE argument may be specified in this command. 8.2.10 $JK This command is used by the SX-1 smart antenna to enable the e-Dif option. This command will have the following format: $JK,x…<CR><LF>...

  • Page 104: Jquery,Guide

    SX-1 module. 8.2.12 $JQUERY,GUIDE This command is used to poll the SX-1 for its opinion on whether or not it is providing suitable accuracy after the both SBAS and GPS have been acquired (up to 5 min). This feature takes into consider the download status of the SBAS ionospheric map and also the carrier phase smoothing of the unit.

  • Page 105: Jreset

    $>JQUERY,GUIDE,YES<CR><LF> Otherwise, it will return the following message: $>JQUERY,GUIDE,NO<CR><LF> 8.2.13 $JRESET This command is used to reset the SLX inside the SX-1 to its default operating parameters. This message has the following format: $JRESET<CR><LF> 8.2.14 $JSAVE Sending this command is required after making changes to the operating mode of the SX-1 receiver.

  • Page 106: Jshow

    8.2.15 $JSHOW This command is used to poll the SX-1 for the current operating configuration of its internal SLX receiver. This command has the following structure: $JSHOW[,subset] <CR><LF> Using the $JSHOW command without the optional ‘,subset’ field will provide a complete response from the receiver. An example of this response follows: $>JSHOW,BAUD,9600...
  • Page 107 This line indicates that the current differential mode is WAAS This line indicates the status of the altitude aiding feature. The SX-1 does not support this feature. This line indicates the current elevation mask cutoff angle, in degrees. This line indicates the current seed position used for startup, in decimal degrees.
  • Page 108 8.2.16 $JT This command displays the type of receiver engine within the SX-1 module and has the following format: $JT<CR><LF> The receiver will return the following response, indicating that the receiver is an SX1g (‘g’...

  • Page 109: Jbin

    Binary message containing process statistics Bin98 1 or 0 Binary message containing satellite and almanac information. Bin99 5, 1, 0, or .2 Binary message containing GPS diagnostic information. The SX-1 will reply with the following response: SX-1 Evaluation Integrator’s Manual...

  • Page 110: Gps Commands

    8.3 GPS Commands This section describes the selection of commands specific to the configuration and operation of the SX-1 antenna’s internal GPS engine. The following table provides a brief description of the commands supported by the GPS engine for its configuration and operation.

  • Page 111: Jasc

    Course Over Ground and Ground Speed GPZDA 5, 1, 0, or .2 Time and Date When the ‘,OTHER’ data field is specified (without the square brackets), this command will enact a change on the other port. SX-1 Evaluation Integrator’s Manual...

  • Page 112: Jage,Age

    The default setting for the SX-1 is 1800 seconds, however, you may change this value as you feel appropriate. Using COAST technology, the SX-1 is able to use old correction data for extended periods of time. If you choose to use a maximum correction age...

  • Page 113: Jmask

    When the ‘,OTHER’ data field is specified (without the square brackets), this command will turn on the four NMEA messages on the other port. There are no variable data fields for this message. The SX-1 will reply with the following response: $>...

  • Page 114: Sbas Commands

    This command is used to poll the WAAS demodulator for information relating to your current location and WAAS satellites $JRD1 This command is used to poll the SX-1 for SBAS diagnostic information $JASC,RTCM This feature allows you to configure the SX-1 to output RTCM data from the WAAS demodulator SX-1 Evaluation Integrator’s Manual...

  • Page 115: Jwaasprn

    $JWAASPRN[,sv1[,sv2]] <CR><LF> Where ‘sv1’ is the PRN number of the first SBAS satellite and ‘sv2’ is the PRN number of the second SBAS satellite. ‘sv1’ or both ‘sv1’ and ‘sv2’ may be specified. SX-1 Evaluation Integrator’s Manual...

  • Page 116: Jgeo

    8.4.2 $JGEO This message is used to display information related to the current frequency of SBAS, and its location in relation to the SX-1’s antenna. To query the SX-1 for the currently used SBAS satellite information, use the following query: $JGEO<CR><LF>...

  • Page 117: Jrd1

    WAAS satellite not being currently used. Both outputs follow the format in the previous table for the $JGEO query. 8.4.3 $JRD1 This command is used to request diagnostic information from the SX-1 module. SX-1 Evaluation Integrator’s Manual...

  • Page 118: Jasc,Rtcm

    To command the SX-1 to output the diagnostic information message for the currently used SBAS satellites at a rate of 1 Hz, use the following query: $JASC,D1,1[,OTHER]<CR><LF> The receiver will respond with the following data message: $> Setting the update rate to zero as follows will turn off this message.

  • Page 119: E-Dif Commands

    ‘$> Save Complete’ response. 8.5.1 $JRAD,1 This command is used to display the current reference position. This command has the following format: $JRAD,1<CR><LF> The SX-1 will reply with a response similar to the following: SX-1 Evaluation Integrator’s Manual...

  • Page 120: Jrad,1,P

    $>JRAD,1,51.00233513,-114.08232345,1050.212 Upon startup of the SX-1 with the e-Dif application running (as opposed to the SBAS application), no reference position will be present in memory. If you attempt to query for the reference position, the SX-1 will respond with the following message: $>JRAD,1,FAILED,Present Location Not Stable...

  • Page 121: Jrad,2

    This is the longitude of the reference point in degrees decimal degrees. This is the altitude of the reference point in m. The SX-1 will reply with the following response: $>JRAD,lat,lon,alt Note - Both latitude and longitude must be entered as values with a decimal place.

  • Page 122: Jrad,3

    The SX-1 will reply with the following response: $>JRAD,2,OK 8.5.5 $JRAD,3 This command is used for two primary purposes. The first is to invoke the e-Dif function once the unit has started up (with the e-Dif application active). The second purpose is to update the e-Dif solution (calibration) using the current position as opposed to the reference position used by the $JRAD,2 command.

  • Page 123: Data Messages

    5 Hz Time and Date 1 Hz SBAS diagnostic information (proprietary NMEA message) $PCSI,1 1 Hz This is a proprietary beacon status message Note - For clarity, each data message will be presented on a new page. SX-1 Evaluation Integrator’s Manual...

  • Page 124: Gga Data Message

    Antenna altitude Altitude units, M = meters ±xxxx.xx Geoidal separation (needs geoidal height option) Geoidal separation units, M = meters Age of differential corrections in seconds Reference station identification Checksum <CR><LF> Carriage return and line feed SX-1 Evaluation Integrator’s Manual...

  • Page 125: Gll Data Message

    = E or s = W, for East or West longitude hhmmss.ss UTC time in hours, minutes, and seconds of GPS position Status, s = A = valid, s = V = invalid Checksum <CR><LF> Carriage return and line feed SX-1 Evaluation Integrator’s Manual...

  • Page 126: Gsa Data Message

    Satellites used in the position solution, a null field occurs if a channel is unused Position Dilution of Precision (PDOP) = 1.0 to 9.9 Horizontal Dilution of Precision (HDOP) = 1.0 to 9.9 Vertical Dilution of Precision (VDOP) = 1.0 to 9.9 Checksum <CR><LF> Carriage return and line feed SX-1 Evaluation Integrator’s Manual...

  • Page 127: Gst Data Message

    Standard deviation of semi-minor axis of error ellipse (meters) Orientation of semi-major axis of error ellipse (degrees) Standard deviation of latitude error (meteers) Standard deviation of longitude error (meters) Standard deviation of altitude error (meters) Checksum <CR><LF> Carriage return and line feed SX-1 Evaluation Integrator’s Manual...

  • Page 128: Gsv Data Message

    Total number of satellites in view Satellite number Elevation in degrees, ee = 0 to 90 Azimuth (true) in degrees, aaa = 0 to 359 SNR (dB) + 30, ss = 0 to 99 Checksum <CR><LF> Carriage return and line feed SX-1 Evaluation Integrator’s Manual...

  • Page 129: Rmc Data Message

    Track made good, referenced to true north ddmmyy UTC date of position fix in day, month, year Magnetic Variation in degrees Variation sense v = E = East, v = W = West Checksum <CR><LF> Carriage return and line feed SX-1 Evaluation Integrator’s Manual...

  • Page 130: Rre Data Message

    Field Description Number of satellites used in position computation Satellite number Range residual in meters hhh.h Horizontal position error estimate in meters vvv.v Vertical position error estimate in meters Checksum <CR><LF> Carriage return and line feed SX-1 Evaluation Integrator’s Manual...

  • Page 131: Vtg Data Message

    Speed over ground, 000 to 999 knots Speed over ground units, u = N = Nautical mile/h ggg.gg Speed over ground, 000 to 999 km/h Speed over ground units, u = K = kilometer/h Checksum <CR><LF> Carriage return and line feed SX-1 Evaluation Integrator’s Manual...

  • Page 132: Zda Data Message

    Day, dd = 0 to 31 Month, mm = 1 to 12 yyyy Year Local zone description in hours, xx = -13 to 13 Local zone description in minutes, yy = 0 to 59 Checksum <CR><LF> Carriage return and line feed SX-1 Evaluation Integrator’s Manual...

  • Page 133: Rd1 Data Message

    Checksum <CR><LF> Carriage return and line feed The following table describes the DSP status. The DSP status should be 17, 1B, or 1F when SBAS tracking has been achieved. SX-1 Evaluation Integrator’s Manual...
  • Page 134 The number of satellites that are tracked, have an ephemeris, which is healthy, and are above the elevation mask The number of satellites above the elevation mask The number of satellites with differential The number of satellites with no differential SX-1 Evaluation Integrator’s Manual...

  • Page 135: Pcsi,1 Beacon Status Message

    This message contains a variety of information relating to the status of a CSI Wireless SBX engine, if interfaced to the SX-1. This information is included as the $PCSI,1 output message from the SX-1 is intelligently routed through the SX-1 to the port from which the $PCSI,1 message was requested. $PCSI,CS0,PXXX-Y.YYY,SN,fff.f,M,ddd,R,SS,SNR,MTP,Q,ID,H,T...

  • Page 136: Gpmsk Beacon Tune Command

    Command to turn on diagnostic information. $PCSI,1 This command is used to get beacon status information from the SBX beacon engine inside the SX-1 8.7.1 $GPMSK Beacon Tune Command This command instructs the SBX to tune to a specified frequency and automatically select the correct MSK rate.

  • Page 137: Pcsi,1 Beacon Status Command

    This command is used to obtain $PCSI,CS0 beacon status data from an SBX engine when interfaced to the SX-1 Port C. When this command is sent through either Port A or B, it will automatically be routed to Port C.
  • Page 138 If you wish to have the CS0 message output for every power cycle, use the following derivative of this command: $PCSI,1,x,S<CR><LF> Response: $PCSI,ACK,1,x,S Where x is the desired output period in seconds. The ‘S’ field must be present and be capitalized. SX-1 Evaluation Integrator’s Manual...

  • Page 139: Binary Data

    9. Binary Data The SX-1 supports a selection of binary data messages that provide improved communication port efficiency. 9.1 Binary Message Structure The Binary messages supported by the Vector Sensor are in an Intel Little Endian format for direct read in a PC environment. You can find more information on this format at the following Web site.

  • Page 140: Bin 80

    Altitude above the ellipsoid in Float meters VNorth Velocity north in m/s Float VEast Velocity East in n/s Float Velocity up in m/s Float Positive NavMode Navigation mode: Unsigned Bits 0 through 6 short = Navmode 0 = No fix SX-1 Evaluation Integrator’s Manual...

  • Page 141: Bin 2

    Horizontal dilution of precision Unsigned Positive scaled by 10 (0.1 units) short VDOPTimes10 Vertical Dilution of precision Unsigned Positive scaled by 10 (0.1 units) short WAAS PRN PRN and tracked or used Unsigned See below bitmask status masks short SX-1 Evaluation Integrator’s Manual...

  • Page 142: Bin 94

    This message has a BlockID of 93 and is 45 bytes excluding the header and epilogue. This message contains information relating to the WAAS ephemeris. The following table describes the contents of this message in order SX-1 Evaluation Integrator’s Manual...

  • Page 143: Bin 96

    This message contains ionospheric and UTC conversion parameters. The following table describes the details of this message in order. Table 9-6 Bin 94 Message Name Components Type Bytes Value a0,a1, AFCRL alpha parameters Double 8 x 4 = 32 SX-1 Evaluation Integrator’s Manual...

  • Page 144: Bin 97

    Unparsed SF 1 message Unsigned long 4 x 10 = 40 SF2words[10 Unparsed SF 2 message Unsigned long 4 x 10 = 4 0 SF3words[10 Unparsed SF 3 message Unsigned long 4 x 10 = 40 SX-1 Evaluation Integrator’s Manual...

  • Page 145: Bin 98

    • Bits 24-31: Cycle Slip Counter (Increments by 1 every cycle slip with natural rollover after 255) UlDoppler_FL • Bit 0: 1 if Valid Phase, 0 otherwise • Bit 1: 1 if Track Time > 25.5 seconds, 0 otherwise • Bits 2-3: Unused SX-1 Evaluation Integrator’s Manual...

  • Page 146: Bin 99

    Unsigned long Future use Spare 3 Not used at this time Unsigned long Future use Spare 4 Not used at this time Unsigned short Future use Spare 5 Not used at this time Unsigned short Future use SX-1 Evaluation Integrator’s Manual...

  • Page 147: Table 9-10 Bin 98 Message

    Channel number (groups of 8) Byte 0 to 7 8 to 15 16 to 23 24 to 31 AlmVFlag Almanac valid flag Byte 0 = not logged 1 = invalid 2 = valid 3 = has data (not yet validated) SX-1 Evaluation Integrator’s Manual...

  • Page 148: Table 9-11 Bin 99 Message

    ChannelData 12 structures (see below) Structure 12 x See following table containing tracking data array 24 = for each of the 12 receiver channels ClockErrAtL1 The clock error of the Short -32768 to 32768 SX-1 Evaluation Integrator’s Manual...
  • Page 149 Almanac health from sub frame 4 of Byte See ICD-GPS-200 the GPS message Elev Elevation angle in degrees Char -90 to 90 Azimuth ½ the azimuth in degrees Byte 0 to 180 degrees represents 0 to 360 SX-1 Evaluation Integrator’s Manual...
  • Page 150 GPS solution for this chanel VelResid 10 times the velocity residual from Short the GPS solution for this channel DoppHZ Expected Doppler for this channel Short in Hz NCOHz Carrier track offset for this channel Short in Hz SX-1 Evaluation Integrator’s Manual...

  • Page 151: Frequently Asked Questions

    Q – Do I need to use the 1 PPS and Event Marker? A – No, these are not necessary for operation of the SX-1. Q - What should I do with the Manual Mark input if I’m not going to use it? A - Since this signal is active low, do not connect the pin.

  • Page 152: General

    GPS equipment. Further, you will need circuit design and layout resources plus mechanical expertise. Q – What type of assistance can I expect from CSI Wireless when integrating the SX-1 module? A – Integration of a GPS module has a number of benefits for our customers: lower system cost, improve branding (rather than re-labelling an existing product), better control of system design, and many more.
  • Page 153 This can be easily implemented through development of a custom software application running on a PDA product. Q – How does the SX-1 compare to competitor’s products? SX-1 Evaluation Integrator’s Manual...

  • Page 154: Support And Repairs

    I can’t isolate? A - We recommend that you contact your dealer first. With their experience with this and other products from CSI Wireless, they’re likely to help you isolate a problem. If the issue is beyond the capability or experience of your dealer, either they or you can speak with a Technical Service Representative from CSI Wireless.

  • Page 155: Troubleshooting

    They may be able to provide some in- person assistance too. If this either isn’t viable or does not solve the problem, CSI Wireless Technical Support is available during normal business hours to help solve the problem. You may reach Technical...

  • Page 156: Power, Communication, And Configuration

    10.5 Power, Communication, and Configuration Q - My SX-1 system doesn’t appear to be communicating, what do I do? A - This could be one of a few issues: 1. Examine the SX-1 cables and connectors for signs of damage.
  • Page 157 A - Yes, the ports are independent. For instance, you may have one port set to 4800 and the other to 19,200, or vice versa. Q - Am I able to have the SX-1 module output different NMEA messages through the two ports? A - Yes, you may have different NMEA messages turns on for the two serial ports.

  • Page 158: Gps Reception And Performance

    $JSAVE if you feel it’s necessary, however, it is not required. Q - What is the best software tool to use to communicate with the SX-1 and configure it? A - We use two different software applications at CSI Wireless for this application: •...

  • Page 159: Sbas Reception And Performance

    Q - Do I have to be careful when using the SX-1 to ensure that it tracks properly? A – For best performance, you have to be careful such that the hemisphere above the SX-1’s antenna is unobstructed for satellite tracking.

  • Page 160: E-Dif

    SLXMon utility discussed in Chapter 5 is a useful tool that provides this information without needing to use NMEA commands. Q - Does it matter much if the SX-1 is frequently loosing lock on SBAS due obstructions and the low satellite elevation angles at my geographic...

  • Page 161: External Corrections

    A - This could be due to a number of issues: • Make sure that the corrections are of an RTCM SC-104 protocol. • Check to see that the baud rates of the port used by the SX-1 matches that of the external correction source •...
  • Page 162 Q - Will the method of mounting the antenna (magnetic mount, surface mount, or the pole mount) affect SX-1 performance? A – No, all methods of mounting the SX-1 are equally suited for its use. Q - Can I use a vehicle’s power system to operate the SX-1 Evaluation...

  • Page 163: Troubleshooting

    Check receiver power status (this may be done with an ammeter) • Verify that SX-1 is locked to a valid DGPS signal (this can often be done on the receiving device or with the use with SLXMon running on a PC) •...
  • Page 164 RTCM input port (transmit from the source must go to receive of the RTCM input port and grounds must be connected - Refer to Appendix B) • Non-differential GPS output Verify SX-1 SBAS and lock status (or external source is locked) SX-1 Evaluation Integrator’s Manual...

  • Page 165: Appendix A - Specifications

    Appendix A - Specifications This appendix provides the operational, mechanical, electrical, physical, and environmental specifications of the SX-1 Evaluation system and SX-1 module. Table A-1 SX-1 Evaluation Enclosure Specifications Internal GPS Engine Operational Specifications Item Specification Frequency 1.575 GHz Channels...
  • Page 166 Environmental Specifications Item Specification Storage temperature -40°C to 85°C Operating temperature -30°C to 70°C Humidity 95% Non-Condensing Table A-2 SX-1 Module Specifications Item Specification Frequency 1.575 GHz Channels 12 parallel tracking Horizontal accuracy < 1 m 95% Max position update Rate...
  • Page 167 Environmental Specifications Item Specification Storage temperature -40°C to 85°C Operating temperature -30°C to 70°C Humidity 95% Non-Condensing SX-1 Evaluation Integrator’s Manual...
  • Page 168 SX-1 Evaluation Integrator’s Manual...

  • Page 169: Appendix B - Interface

    To establish communications between the SX-1 Evaluation system and your data logging or navigation device in this mode of operation, you must: • Connect Pin-2 - transmit (TX) of the SX-1 Port A or B to the receive pin (RX) of the data logging or navigation device.

  • Page 170: Figure B-1 Gps Data Interface

    RTCM Data Output To output only RTCM correction data from the internal SBAS correction source from Port A or B of the SX-1 Evaluation system, use the following procedure: • Turn off all NMEA and binary messages using the $JOFF<CR><LF> command •...

  • Page 171: Figure B-2 Rtcm Data Output Interface

    GPS receiver. Refer to Section 5.3.7 for instructions related to setting the SX-1 baud rate. External Correction Input In this operating mode, an external correction device inputs RTCM correction data through an SX-1 serial port. In order to accomplish this, SX-1 Evaluation Integrator’s Manual...
  • Page 172 $JDIFF command. To configure external correction input on Port B you must: • Communicate with the SX-1 on Port A. Ensure that the baud rate of Port B and the external correction source match by issuing the appropriate $JBAUD command.
  • Page 173 3 RX RTCM Figure B-3 External Correction Input Interface Note - For successful communications, the baud rate of the SX-1 differential port must be set to match that of the external correction source. The correction source must support an RS- 232 interface level and the baud rates between each device must match.
  • Page 174 SX-1 Evaluation Integrator’s Manual...

  • Page 175: Appendix C - Surface Mount Template

    3D coordinates. Tracking of only three satellites reduces the position fix to 2D coordinates (horizontal with fixed vertical). The GPS receiver calculates its position with respect to the phase center of the GPS antenna. The latitude, longitude, and altitude of the antenna are SX-1 Evaluation Integrator’s Manual...
  • Page 176 (currently set to a zero effect), atmospheric errors, timing errors, satellite orbit errors, and multipath. Differential GPS (DGPS) is essentially a differencing process that removes sources of error from the GPS position solution and improves the integrity of the GPS position solution. SX-1 Evaluation Integrator’s Manual...
  • Page 177 In addition to the conventional differential positioning with internal sources of corrections, the Vector Sensor also has a documented binary raw measurement protocol. A RINEX translator is available from CSI Wireless in the event that this may be useful, in addition to some C code snippets to aid in integrating the binary format itself into your own application.
  • Page 178 The remote receiver corrects its satellite range measurements using these differential corrections, yielding a much more accurate position. This is the predominant DGPS strategy used for a majority of real-time applications. Positioning using corrections generated by DGPS SX-1 Evaluation Integrator’s Manual...
  • Page 179 Space Based Augmentation Systems (SBAS) such as the European Geostationary Navigation Overlay System (EGNOS) and the Japanese MT-SAT Satellite-based Augmentation System (MSAS) use this data format. The SX-1 system is compatible with each of these differential services. SX-1 Evaluation Integrator’s Manual...
  • Page 180 • Satellite constellation geometry, often expressed as a Dilution of Precision (DOP) • Magnitude of GPS signal multipath present at the remote station • Quality of the GPS receiver being used at both the reference and remote stations SX-1 Evaluation Integrator’s Manual...
  • Page 181 The distance between a remote user and the reference station can sometimes be considerable, such as when using 300 kHz DGPS radiobeacons (not supported by the SX-1 directly unless augmented with a CSI Wireless SBX module). Consequently, some of the errors associated with GPS at the base station differ somewhat from those at the remote user’s location.
  • Page 182 Compared to using a DGPS beacon, the effect of geographic proximity to a single reference station is minimized resulting in more consistent system performance throughout all locations within the network. SX-1 Evaluation Integrator’s Manual...
  • Page 183 Additionally, if the satellites are evenly spread around the receiver, rather than grouped in a few regions of the sky, a lower DOP (stronger solution) will result. SX-1 Evaluation Integrator’s Manual...
  • Page 184 Higher accuracy GPS receivers are able to achieve sub-1 meter horizontal accuracy 95% of the time using real-time DGPS transmissions. The SX-1 module falls in to this latter category. Space Based Augmentation Systems...
  • Page 185 Civil Aviation Bureau (JCAB). China has a similar program for a SBAS and the service is named the Chinese Satellite Navigation Augmentation System (SNAS). The SX-1 is capable of receiving correction data from all compatible SBAS. EGNOS is currently in a prototyping phase, referred to as the EGNOS System Test Bed (ESTB) and which has been broadcasting a test signal since February 2000.
  • Page 186 EGNOS use Inmarsat-III transponders). • The user segment consists of the user equipment, such as an integration based upon the SX-1 module A SBAS uses a state-based approach in their software architecture. This means that a separate correction is made available for each error source rather than the sum effect of errors on the user equipment’s range...
  • Page 187 To enhance the information provided by SBAS, the SX-1 system extrapolates the ionospheric information beyond the broadcast information. This increases the usable geography for WAAS and is discussed in Section 1.5.5. This feature helps to improve the usable coverage area of a SBAS service.
  • Page 188 COAST technology helps to maintain system performance during times of differential outage. When using SBAS correction data, the SX-1 is able to provide you with the azimuth and elevation of the SBAS available satellites via a NMEA serial port command to aid in determining their position with respect to the built-in antenna.
  • Page 189 SBAS may not be desirable or possible, as four or greater satellites (with correctors) must be available to compute a DGPS position. The next section provides further information on the ionospheric map features of SBAS and the SX-1 module. SX-1 Evaluation Integrator’s Manual...

  • Page 190: Figure C-1 Waas Coverage

    Figure C-1 WAAS Coverage SX-1 Evaluation Integrator’s Manual...

  • Page 191: Figure C-2 Egnos Coverage

    Figure C-2 EGNOS Coverage SX-1 Evaluation Integrator’s Manual...
  • Page 192 To improve upon the ionospheric map provided by SBAS, the SX-1 module extrapolates a larger ionospheric map from the broadcast coverage map, extending its effective coverage. This allows the SX-1 to be used successfully in regions that competitive products may not.

  • Page 193: Figure C-3 Broadcast Waas Inonspheric Correction Map

    Figure C-3 Broadcast WAAS Ionospheric Correction Map Figure C-4 Extrapolated WAAS Ionospheric Correction Map SX-1 Evaluation Integrator’s Manual...
  • Page 194 Figure C-5 Broadcast EGNOS Ionospheric Correction Map Figure C-6 Extrapolated EGNOS Ionospheric Correction Map SX-1 Evaluation Integrator’s Manual...

  • Page 195: Appendix - D Resources

    Interfaces, ICD-GPS-200, April 12, 2000, 2250 E. Imperial Highway, Suite 450, El Segundo, CA 90245-3509, www.navcen.uscg.gov/gps/geninfo/default.htm CSI Web Site This following address is the CSI Wireless Web site which provides detailed information on all products offered by CSI Wireless. www.csi-wireless.com SX-1 Evaluation Integrator’s Manual...
  • Page 196 This site contains information relating to past performance, real-time performance, and broadcast schedule of EGNOS www.esa.int/export/esaEG/estb.html Solar and Ionospheric Activity Web Sites The following sites are useful in providing details regarding solar and ionospheric activity. iono.jpl.nasa.gov//latest.html iono.jpl.nasa.gov//gim_dailymovie.html www.spaceweather.com www.maj.com/sun/noaa.html SX-1 Evaluation Integrator’s Manual...
  • Page 197 SX-1 Evaluation Integrator’s Manual...

  • Page 198: Index

    $JPOS, 75 $JQUERY,GUIDE, 75 $JRAD,1, 90, 91 $JRAD,1,P, 91 DATA $JRAD,2, 92 Pin-out, 6, 7, 26 $JRAD,3, 92 Default NMEA Message Output, 5, 28 $JRD1, 88 Default Parameters, 6, 27 $JRESET, 76 DGPS Errors, 150 $JSAVE, 76 SX-1 Evaluation Integrator’s Manual...
  • Page 199 Selective Availability (SA), 146 Placement, 24 Serial Port Defaults, 5, 28 Power Considerations, 23 Shielding, 47 SLXMon, 4, 57 LED Indicators, 29, 34, 45 Temperature, 23 Troubleshooting, 133 Tune Mode Multipath, 153 WAAS Automatic Tracking, 11 SX-1 Evaluation Integrator’s Manual...
  • Page 200 Bit Error Rate, 12 Receiver Performance, 11 WGS-84, 146 Update Rates, 11 www.csi-wireless.com, xxv WAAS SX-1 Evaluation Integrator’s Manual...

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