Garmin 36 Technical Specification

GPS 35/36 T racPak

GPS SMART ANTENNA

TECHNICAL SPECIFICA TION

GARMIN

· 1200 E. 151st Street · Olathe, Kansas

(913) 397-8200 · (913) 397-8282 FAX

66062 ·

All rights reserved. No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, for any purpose without the express written permission of GARMIN.

Information in this document is subject to change without notice. GARMIN reserves the right to change or improve their products and to make changes in the content without obligation to notify any person or organization of such changes or improvements.

January, 1999 190-00104-00 Rev. D

CAUTION

The GPS system is operated by the government of the United States which is solely responsible for its accuracy and maintenance. Although the GPS 35/36 is a precision electronic NAVigation AID (NAVAID), any NAVAID can be misused or misinterpreted, and therefore become unsafe. Use the GPS 35/36 at your own risk. To reduce the risk, carefully review and understand all aspects of this Technical Manual before using the GPS 35/36. When in actual use, carefully compare indications from the GPS 35/36 to all available navigation sources including the information from other NAVAIDs, visual sightings, charts, etc. For safety, always resolve any discrepancies before continuing navigation.

NOTE

This device has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

This device generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this device does cause harmful interference to radio or television reception, which can be determined by turning the device off and on, you are encouraged to try to correct the interference by one or more of the following measures:

· Reorient or relocate the receiving antenna.

· Increase the separation between this device and the receiver.

· Connect this device to an outlet on a different circuit than that to which the receiver is connected.

· Consult the dealer or an experienced radio/TV technician for help.

This device contains no user-serviceable parts. Repairs should only be performed by an authorized GARMIN servi ce center. Unauthorized repairs or modifications to this device could void your warranty and your authority to operate this device under Part 15 regulations.

TABLE OF CONTENTS

1. Introduction 1

1.1 Overview 1

1.2 Features 2

1.3 Technical Specifications 2

1.4 Application 4

2. Operational Characteristics 5

2.1 Self Test 5

2.2 Initialization 5

2.3 Navigation 6

2.4 Satellite Data Collection 7

3. Hardware Interface 9

3.1 Mechanical Dimensions 9

3.2 Mounting Configurations and Options 11

3.3 Connection Wiring Description 15

4. Software Interface 17

4.1 NMEA Received Sentences 17

4.2 NMEA Transmitted Sentences 21

4.3 Baud Rate Selection 28

4.4 RTCM Received Data 29

A. Earth Datums A-1

SECTION 1

INTRODUCTION

1.1 OVERVIEW

The GARMIN GPS 35/36 is a complete GPS receiver, including an embedded antenna, designed for a broad spectrum of OEM (Original Equipment Manufacturer) system applications. Based on the proven technology found in other GARMIN 12 channel GPS receivers, the GPS 35/36 will track up to 12 satellites at a time while providing fast time-to-first-fix, one second navigation updates and low power consumption. Its far reaching capability meets the sensitivity requirements of land navigation as well as the dynamics requirements of high performance aircraft.

The GPS 35/36 design utilizes the latest technology and high level circuit integration to achieve superior performance while minimizing space and power requirements. All critical components of the system including the RF/IF receiver hardware and the digital baseband are designed and manufactured by GARMIN to ensure the quality and capability of the GPS 35/36. This hardware capability combined with software intelligence makes the GPS 35/36 easy to integrate and use.

The GPS 35/36 is designed to withstand rugged operating conditions and is completely water resistant. The GPS 35/ 36 is a complete GPS receiver that requires minimal additional components be supplied by an OEM or system integrator. A minimum system must provide the GPS 35/36 with a source of power and a clear view of the GPS satellites. The system may communicate with the GPS 35/ 36 via a choice of two RS-232 compatible full duplex communication channels. Internal memory backup allows the GPS 35/36 to retain critical data such as satellite orbital parameters, last position, date and time. End user interfaces

such as keyboards and displays are added by the application designer.

1.2 FEATURES

The GPS 35/36 provides a host of features that make it easy to integrate and use.

1) Full navigation accuracy provided by Standard Positioning Service (SPS)

2) Compact design ideal for applications with minimal space

3) High performance receiver tracks up to 12 satellites while providing fast first fix and low power consumption

4) Differential capability utilizes real-time RTCM corrections producing 3-10 meter position accuracy

5) Internal clock and memory are sustained by a memory backup battery or optional external standby power

6) User initialization is not required

7) Navigation mode (2D or 3D) may be configured by the user

8) Two communication channels and user selectable baud rates allow maximum interface capability and

flexibility

1.3 TECHNICAL SPECIFICATIONS

Specifications are subject to change without notice.

1.3.1 Physical Characteristics

1) Single construction integrated antenna/receiver.

2) Weight: 4.4 oz, (124.5 g), not including cable

3) Size: 2.230" (w) x 3.796" (l) x 1.047" (h), (56.64 mm x 96.42 mm x 26.60 mm)

1.3.2 Environmental Characteristics

1) Operating temperature: -30°C to +85°C (internal temperature)

2) Storage temperature: -40°C to +90°C

1.3.3 Electrical Characteristics

1) Input voltage: 10 to 30 VDC, unregulated.

2) Typically draws 150 mA @ 12 VDC

3) Backup power: Internal 3V Lithium coin cell battery, up to 10 year life

1.3.4 Performance

1) Tracks up to 12 satellites

2) Update rate: 1 second

3) Acquisition time

- 15 seconds warm (all data known)

- 45 seconds cold (initial position, time and

almanac known, ephemeris unknown)

- 5.0 minutes AutoLocateTM (almanac known, initial

position and time unknown)

- 5 minutes search the sky (no data known)

4) Position accuracy:

Differential GPS (DGPS): 5 meters RMS Non-differential GPS: 15 meters RMS (100 meters

with Selective Availability on)

5) Velocity accuracy: 0.2 m/s RMS steady state (subject to Selective Availability)

6) Dynamics: 999 knots velocity, 6g dynamics

1.3.5 Interfaces

1) Dual channel RS-232 compatible with user selectable baud rate (1200, 2400, 4800, 9600)

2) NMEA 0183 Version 2.0 ASCII output (GPALM, GPGGA, GPGSA, GPGSV, GPRMC, GPVTG, PGRME, PGRMT, PGRMV, PGRMF, LCGLL, LCVTG)

Inputs

- Initial position, date and time (not required)

- Earth datum and differential mode configuration

command, almanac.

Outputs

- Position, velocity and time

- Receiver and satellite status

- Differential Reference Station ID and RTCM Data

age

- Geometry and error estimates

3) Real-time Differential Correction input (RTCM format)

1.4 APPLICATION

TYPICAL APPLICATION ARCHITECTURE

SECTION 2

OPERATIONAL CHARACTERISTICS

This section describes the basic operational characteristics of the GPS 35/36. Additional information regarding input and output specifications are contained in Section 4.

2.1 SELF TEST

After input power has been applied to the GPS 35/36 and periodically thereafter, the unit will perform critical self test functions and report the results over the output channel(s). The following tests will be performed:

1) RAM check

2) ROM test

3) Receiver test

4) Real-time clock test

5) Oscillator check

In addition to the results of the above tests, the GPS 35/36 will report software version information.

2.2 INITIALIZATION

After the initial self test is complete, the GPS 35/36 will begin the process of satellite acquisition and tracking. The acquisition process is fully automatic and, under normal circumstances, will take approximately 45 seconds to achieve a position fix (15 seconds if ephemeris data is known). After a position fix has been calculated, valid position, velocity and time information will be transmitted over the output channel(s).

Like all GPS receivers, the GPS 35/36 utilizes initial data such as last stored position, date and time as well as satellite orbital data to achieve maximum acquisition performance. If significant inaccuracy exists in the initial data, or if the orbital data is obsolete, it may take 5.0 minutes to achieve a navigation solution. The GPS 35/36 Autolocate

feature is capable of automatically determining a navigation solution without intervention from the host system. However, acquisition performance can be improved if the host system initializes the GPS 35/36 following the occurrence of one or more of the following events:

1) Transportation over distances further than 1500 kilometers

2) Failure of the internal memory battery without system standby power

3) Stored date/time off by more than 30 minutes

See Section 4 for more information on initializing the GPS 35/36.

2.3 NAVIGATION

After the acquisition process is complete, the GPS 35/36 will begin sending valid navigation information over its output channels. These data include:

1) Latitude/longitude/altitude

2) Velocity

3) Date/time

4) Error estimates

5) Satellite and receiver status

Normally the GPS 35/36 will select the optimal navigation mode (2D or 3D) based on available satellites and geometry considerations. The host system, at its option, may command

the GPS 35/36 to choose a specific mode of navigation, such as 2D. The following modes are available:

1) 2D exclusively with altitude supplied by the host system (altitude hold mode)

2) 3D exclusively with altitude computed by the GPS 35/ 36

3) Automatic mode in which the board set determines

the desired mode based on satellite availability and geometry considerations

When navigating in the 2D mode (either exclusive or automatic), the GPS 35/36 utilizes the last computed altitude or the last altitude supplied by the host system, whichever is newer. The host system must ensure that the altitude used for 2D navigation is accurate since the resulting position error may be as large as the altitude error. See Section 4 for more information on altitude control.

The GPS 35/36 will default to automatic differential corrections, attempting to apply them to the satellite data, in order to produce a differential (DGPS) solution. The host system, at its option, may also command the GPS 35/36 to choose differential only mode. When navigating in the differential only mode, the GPS 35/36 will output a position only when a differential solution is available.

2.4 SATELLITE DATA COLLECTION

The GPS 35/36 will automatically update satellite orbital data as it operates. The intelligence of the GPS 35/36 combined with its hardware capability allows these data to be collected and stored without intervention from the host system. A few key points should be considered regarding this process:

1) If the GPS 35/36 is not operated for a period of six (6) months or more, the unit will “search the sky” in order to collect satellite orbital information. This process is

+ 27 hidden pages