Kongsberg 1007D Operator's Manual

Kongsberg Maritime
Operator manual
1007D
Altimeter series
974-72007001/1.0
1007D Altimeter Series
Operators manual
Document revisions
Version
1.0
Version 1.0
Date Written by Checked by Approved by
August 06, 2010 BK BC BC
- First release
Document history
About this document
The information contained in this document is subject to change without prior notice. Kongsberg Mesotech Ltd. shall not be liable for errors contained herein, or for incidental or consequential damages in connection with the furnishing, performance, or use of this document.
© 2008 Kongsberg Mesotech Ltd. All rights reserved. No part of this work covered by the copyright hereon may be reproduced or otherwise copied without prior permission from Kongsberg Mesotech Ltd.
1007D Altimeter Operators Manual 974-72007001/1.0
Table of contents
1 GENERALDESCRIPTION....................................................................................................................1
1.1FEATURES................................................................................................................................................1
1.2OPTIONS.................................................................................................................................................2
1.3INTRODUCTION.........................................................................................................................................2
2 THEORYOFOPERATION...................................................................................................................5
2.1OPERATINGMODE....................................................................................................................................8
2.2RANGERESOLUTION..................................................................................................................................9
2.3OVERRANGECONDITION.........................................................................................................................10
2.4RECEIVERGAINADJUSTMENT....................................................................................................................11
2.5AUTOGAINADJUSTMENT.......................................................................................................................11
3 INSTALLATION................................................................................................................................13
3.1MOUNTINGPOSITION.............................................................................................................................. 13
3.2ELECTRICALCONNECTION.........................................................................................................................14
3.3SYSTEMCHECKOUT.................................................................................................................................16
3.4DEPLOYMENT.........................................................................................................................................17
3.5MAINTENANCE.......................................................................................................................................17
4 TELEMETRY....................................................................................................................................18
4.1808MODEMESSAGES............................................................................................................................19
4.1.1 UplinkMessages.......................................................................................................................19
4.1.2 DownlinkMessages..................................................................................................................20
4.2809MODEMESSAGES............................................................................................................................21
4.2.1 UplinkMessages.......................................................................................................................21
4.2.2 DownlinkMessages..................................................................................................................22
5 OPTIONS........................................................................................................................................32
5.1HARDWAREHOLDOFF............................................................................................................................. 32
5.2EXTERNALSYNCHRONIZATION....................................................................................................................32
5.3AUXILIARYSERIALOUTPUT........................................................................................................................33
5.4ANALOGOUTPUT....................................................................................................................................33
5.5ALTIMETERRECONFIGURATIONUTILITY........................................................................................................ 34
6 TIPSFORSUCCESSFULALTIMETRY..................................................................................................36
7 APPENDIX‐1007DALTIMETERALTITUDEDETECTIONALGORITHM.................................................38
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974-72007001/1.0 1007D Altimeter Operators Manual
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VI
1007D Altimeter Operators Manual 974-72007001/1.0 General Description Page 1
1 GENERAL DESCRIPTION
The 1007D digital altimeters are small, rugged, light-weight instruments for deep ocean applications, where dimensions and weight are key equipment selection factors. The 1007D is ideally suited for applications such as positioning, berthing, measurement of above-seabed altitude or depth below the water surface.
1.1 Features
200 kHz transmit frequency standard (120 kHz or 675
kHz optional)
Configurable settings for operating parameters (range,
resolution, firing rate, pulse width, etc.)
Configurable settings for detection parameters (threshold,
range, return pulse width, etc.)
First or peak-level return based obstacle/bottom detection Adjustable threshold based range measurements User selectable range windowing control RS485 or RS232 serial interface standard 3 basic models available - standalone analog output,
standalone digital serial output, and MS1000 mode (for use with MS1000 system)
808, 809, or NMEA output data formats Adjustable manual gain or automatic gain offset modes Compatible with Kongsberg Mesotech's MS1000 PC-
based sonar imaging / data-logging software. Scope-graph and echo sounding available when operating with MS1000 software.
Kongsberg Mesotech Ltd.
Port Coquitlam, BC - Canada
974-72007001/1.0 1007D Altimeter Operators Manual Page 2 General Description
1.2 Options
RS422 serial interface analog output electrical hold-off control multi-head ping synchronization second serial output for vehicle servo control connector options (contact factory)
1.3 Introduction
The Model 1007D acoustically measures underwater altitude at high resolution, producing a digital and/or analog output proportional to range.
It is primarily intended for remote operation where its output will be connected to a remote PC or MS1000 host, or to other instrumentation such as a data acquisition system or a telemetry system. Consequently, the 1007D does not have any operating controls nor does it have a display.
The 1007D’s processing features, flexibility, and performance are designed to address the requirements of many applications and deployment scenarios. Many of its sonar acquisition and echo verification parameters such as pulse width, receiver gain offset, range limits, and sensitivity are all programmable. Altitude measurements can be output via a serial interface in a number of selectable formats for various interfacing requirements.
Kongsberg Mesotech Ltd.
Port Coquitlam, BC - Canada
1007D Altimeter Operators Manual 974-72007001/1.0 General Description Page 3
The 1007D is capable of measuring altitude at high resolution. A resolution of better than 2.5 millimetres can be achieved for distances up to 38 meters. The resolution is adjustable to allow the operator to optimize the balance between resolution and ping rate.
In its standard stand-alone configuration, the 1007D is connected to a remote PC or computer terminal via an RS485 or RS232 interface. Range measurements are up-linked directly to the host computer in a number of selectable ASCII formats and range units. Legacy Model 808 or 809 Altimeter output formats are also available. Range measurements can also be output to a DC voltmeter from an optional analog interface like that found in our Model 807 Altimeters. The voltage output is directly proportional to the range (10 volts corresponding to maximum range).
The 1007D's programmable gain receiver is controlled by a "Time Varying Gain" (TVG) function to compensate for acoustic return signal losses that increase with range. This process is microprocessor controlled and is applied during each ping, synchronized to the start of the transmit pulse. The TVG function is therefore very stable and accurate, and results in a very stable output signal.
Kongsberg Mesotech Ltd.
Port Coquitlam, BC - Canada
974-72007001/1.0 1007D Altimeter Operators Manual Page 4 General Description
The 1007D is compatible with Kongsberg Mesotech’s MS1000 PC software and related accessories such as the MS1000 Power Supply Box. The MS1000 software can support up to 255 devices (sonar heads and/or 1007D Altimeters) over a single RS485 connection. The 1007D can also be used with the ROV Hub option on the MS1000 that allows several 1071/1171 scanning sonars and 1007D altimeters to be operated and synchronized with a single ethernet cable connection. The MS1000 software displays altitude measurements in a directly readable format in a moveable display window. An analog scope-graph window provides the operator with a visual indication of the aggregate acoustic signal received each ping, plotted as graph of signal­strength vs. range.
The Model 1007D is packaged in a small rugged housing rated for a maximum depth of 3000 meters. A single underwater connector provides a simple cable connection to an external DC power source, and either an external PC or a voltmeter.
Kongsberg Mesotech Ltd.
Port Coquitlam, BC - Canada
1007D Altimeter Operators Manual 974-72007001/1.0
Theory of Operation Page 5
2 THEORY OF OPERATION
The Model 1007D altimeter measures range as a function of the two-way acoustic travel time between its transducer and a reflecting target or sea bottom.
The 1007D range measurement cycle (or ‘ping’) begins by transmitting an acoustic tone burst from its transducer into a narrow conical-shaped beam. This beam pattern depends on the transducer element used, and defines the coverage of the targets which will be illuminated. The acoustic energy is reflected back to the transducer by each target at a delay time proportional to its distance, and at a strength related to its size and reflectivity.
The signal received by the transducer consists of a series of pulses or “returns” corresponding to each insonified target, and is amplified and conditioned by an adjustable gain receiver. The receiver output is sampled, digitized, and stored in internal memory over the duration of the ping, as determined by the altimeter’s current maximum range setting. The sample data is then analyzed by a Digital Signal Processor (DSP) to determine time and distance to the most likely target.
The receiver gain is hardware-controlled by a Time-Varying­Gain (TVG) characteristic to compensate for acoustic energy losses that increase with range:
Ro)-2a(R Log(R/Ro)20 (dB) Gain
Kongsberg Mesotech Ltd.
Port Coquitlam, BC - Canada
974-72007001/1.0 1007D Altimeter Operators Manual Page 6 Theory of Operation
where R = range, Ro = reference range (1m), and a = attenuation constant in dB/range units. The first term compensates for the natural spreading loss proportional to the inverse of the square of the distance, assuming a wide, flat, bottom. The second term compensates for losses due to energy absorption and is directly proportional to the distance, assuming uniform water salinity, temperature, and pressure.
The sampled data set of the received signal may contain numerous ‘returns’ of varying amplitudes due to noise or representing actual targets. The DSP identifies those ‘returns’ that meet the following adjustable criteria as potential candidates for the final range measurement:
a) minimum amplitude (threshold) b) minimum pulse width c) minimum inter-pulse gap width d) minimum range e) maximum range
Adjustments are made to these settings to reduce the detection of spurious and/or low reflectance targets. The minimum range setting can also be adjusted to eliminate nearby targets such as vessel hulls, cables, etc. near the altimeter.
The range of candidate ‘returns’ in the sample data set is estimated as the time the ‘return’ pulse first exceeds a minimum amplitude threshold.
After the candidate ‘returns’ have been identified from the sample data set, one is chosen by the DSP using a decision rule that selects the sea bottom return. The operator can select one of the following decision rules the 1007D uses to determine the sea bottom return:
Kongsberg Mesotech Ltd.
Port Coquitlam, BC - Canada
1007D Altimeter Operators Manual 974-72007001/1.0 Theory of Operation Page 7
a) first return: The selected return is the first return whose
level is above the set threshold. This mode is recommended for obstacle avoidance applications
b) peak return: The selected return is the strongest return
whose level is above the set threshold. This mode is recommended for long range applications in low multipath environments for detection of hard, flat sea bottom.
The acoustic travel time is calculated for the chosen return based on its position in the sample data set, then converted to a range estimate. This estimate is then filtered using an adjustable range window that considers the new range estimate valid only if it is within a range window of the previous estimate. This range window feature can be disabled if desired.
If after each ping a valid range estimate is determined, the range data is either up-linked as an ASCII string from the telemetry interface and/or optionally output as a scaled 0..10V analog output. However, if no return is detected, or if range windowing is enabled and the range estimate of the current ping is outside the range window of the previous ping, an over-range value is output. This over-range value is zero from the digital telemetry interface, and typically +10.24V from the optional analog interface.
Kongsberg Mesotech Ltd.
Port Coquitlam, BC - Canada
974-72007001/1.0 1007D Altimeter Operators Manual Page 8 Theory of Operation
2.1 Operating Mode
Immediately on power-up the 1007D Altimeter scans its RS232/485 telemetry interface for the first ten seconds in order to detect MS1000 telemetry. If successful, the altimeter sets itself up as an MS1000 device for control by an MS1000 PC host. If no MS1000 is detected within the allotted time, the 1007D goes into its factory-configured default mode. These modes are one of the following and are configured at the factory as per customer requirements:
a) 807 mode: operates as a standalone instrument with an
analog output interface, where range measurements are output continuously as a 0…10V signal only. All range, detection, and output scaling settings are configured at the factory as per customer requirements. The 807 mode can only be entered as a power-up default. While operating in this mode, the telemetry type (RS232, RS485, or RS422) is fixed by a factory-configured setting, and cannot be changed.
b) 808 mode: emulates a standalone Model 808
Altimeter, where range measurements are continuously output via a quasi-full-duplex telemetry interface (RS232, RS485, or RS422). In this mode the altimeter accepts XON/XOFF characters from a computer to pause/resume pinging. All range, detection, and output scaling settings are configured at the factory as per customer requirements. This mode can only be entered as a power-up default. During this mode, the telemetry type (RS232, RS485, RS422) is fixed by a factory-configured setting, and cannot be changed.
c) 809 mode: operates as a standalone instrument, where
range measurements are continuously output via a quasi-full-duplex telemetry interface (RS232, RS485, or RS422). Range, detection, and output scaling parameters are programmable via serial commands. This mode can only be entered as a power-up default.
Kongsberg Mesotech Ltd.
Port Coquitlam, BC - Canada
1007D Altimeter Operators Manual 974-72007001/1.0 Theory of Operation Page 9
During this mode, the telemetry type (RS232, RS485, RS422) is fixed by a factory-configured setting, and cannot be changed. This mode emulates the Model 809 Altimeter, providing a pin-compatible serial interface for output/control of altitude measurements via a computer.
d) MS1000 mode: operates as an MS1000 device over an
RS232 or RS485 telemetry interface, and is controlled by MS1000 host software running on a PC. In this mode, the 1007D detects the telemetry type (RS232, RS485) used by the MS1000 host PC. RS-485 telemetry is the most flexible, allowing multiple 1007D altimeters and MS1000-compliant digital sector scanning sonar heads to be connected to a single cable.
The MS1000 mode can also entered from any of the standalone 807, 808, or 809 modes if MS1000 telemetry is detected. However, this is possible only if the altimeter is configured for a telemetry type that agrees with that used by the MS1000 host PC. Further details regarding 1007D setup and control with the MS1000 software can be found in the MS1000’s help utility or in the MS1000 Operator’s Manual.
The 807, 808, and 809 modes are collectively referred to as the standalone 80x modes throughout this document.
2.2 Range Resolution
The 1007D altimeter is capable of resolving distance at very high resolution, limited only by the altimeter's maximum sampling rate (307.2kHz or 2.4mm) and sample memory size (16000 samples). This implies that distances can be measured down to 2.4mm resolution for maximum ranges up to 38 meters.
Kongsberg Mesotech Ltd.
Port Coquitlam, BC - Canada
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