modulation of edm in surveying

View Answer, 10. View Answer, 8. c) 7.5*106 to 5.9*108 Hz b) Super imposition of waves The John A. Dutton e-Education Institute is the learning design unit of the College of Earth and Mineral Sciences at The Pennsylvania State University. To understand the full scope of surveying, you … This cyclic stressing can promote or inhibit fault slip, particularly at the deep roots of faults. All Rights Reserved. They are reflected at the point up to which distance is to be measured from the instrument … Edm is a surveying instrument used to measure the distance electronically. Most modulating EDM devices now use infrared or a visible laser (wavelength a few microns) as the carrier wave, modulated at around 1 GHz to give a modulation wavelength of about 30 cm. Which of the following indicates the correct set of frequency employed in measuring process? Used with survey and 3D point monitoring systems to measure changes in elevation and position of a point. In EDM instruments these waves are generated, modulated and then propagated. Measuring distances for a variety of survey purposes, such as the length of a baseline between two survey stations. The electronic distance measurement instrument (EDM) is a relatively new development in the field of surveying. Once the phase ( ) is determined it is a simple matter of converting phase to distance. View Answer, 3. In 1957, the XIIth General Assembly of the International Scientific Radio Union recommended that the best available value for the velocity of electromagnetic waves in vacuum was : 299 792.5km/s ±0.4km/s. b) Distance calculation To simplify the procedures to obtain accuracy in surveying, the electronic distance measuring method was introduced. 1. 2217 Earth and Engineering Sciences Building, University Park, Pennsylvania 16802 Sanfoundry Global Education & Learning Series – Surveying. d) 7.5*106 to 5*108 Hz With Micro-Dist, however, the two units were interchangeable. a) 10000 m Except where otherwise noted, content on this site is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. a) Phase comparison In 1956 – Ordnance Survey – Geodimeter 4 - 299 792.4km/s ±0.5. Which of the following is constant in the case of frequency modulation? Modern phase techniques are capable of __________ c) Super wave a) Total wave The unit length is the scale on which the EDM measures the distance, and is derived from the fine measuring frequency. Please send comments or suggestions on accessibility to the site editor. Each piece of EDM equipment available at Engineer … b) Measuring wave Area Computation & Tacheometric Surveying, Geographic Information System & Topographic Maps, here is complete set of 1000+ Multiple Choice Questions and Answers, Prev - Surveying Questions and Answers – EDM – Electromagnetic Waves, Next - Surveying Questions and Answers – Types of EDM Instruments, Surveying Questions and Answers – EDM – Electromagnetic Waves, Surveying Questions and Answers – Types of EDM Instruments, Analytical Instrumentation Questions and Answers, Electrical Measurements Questions and Answers, Digital Communication Questions and Answers, Linear Integrated Circuits Questions and Answers, Microwave Engineering Questions and Answers, Electromagnetic Theory Questions and Answers, Electronic Devices and Circuits Questions and Answers, Engineering Physics II Questions and Answers, Wireless & Mobile Communications Questions & Answers, Optical Communications Questions and Answers, Analog Communications Questions and Answers, Surveying Questions and Answers – Remote Sensing – Electromagnetic Energy, Wireless & Mobile Communications Questions & Answers – Linear Modulation Techniques. 6. Electronic distance measurement (EDM) is a method of determining the length between two points using electromagnetic waves. A total station ( TS) or total station theodolite ( TST) is an electronic/optical instrument used for surveying and building construction. EDM (Electrotape) Catalogue number: 1996.0195.01 ... Like the Tellurometer, Micro-Dist used data compression by means of modulation side-band folding. b) 7.5*106 to 4.5*108 Hz A reflector or transmitter receiver at the far end reflects the light or The first edition was published in 1978 by the School of Surveying, Universi­ ty of New South Wales, Sydney, Australia. Surveying Equipment, Measurements and Errors 3.1 EQUIPMENT The procurement and maintenance of surveying equipment, tools and supplies are important parts of the Department’s survey effort. For example, if the EDM sends out a wavelength of 100 meters, then by looking at the fractional part of that 100-meter wavelength, it would be possible to determine the tens of meters in the distance. Here the distance is measured with the help of electro-magnetic waves such as micro wave, infra red wave and other similar waves. Lower frequency is not suitable in_________ View Answer, 4. It is an electronic transit theodolite integrated with electronic distance measurement (EDM) to measure both vertical and horizontal angles and the slope distance from the … In general terms, the instrument can take half the time elapsed between the moment of transmission and the moment of reception, multiply by the speed of light, and find the distance between itself and the retroprism (Distance = Elapsed Time x Rate). Example: if =135o then this would represent Frequencies generated within an electronic distance measuring device (EDM) can be used to determine the elapsed travel time of its signal, because the signal bounces off a reflector (aka corner cube) and returns to where it started. The direction and length of survey lines are measured with the help of an angular measuring device (Theodolite) and distance measuring device ( Tape, chain, EDM, GPS etc.). On the signal's return, the EDM can analyze it and determine the distance. The Pennsylvania State University © 2020, GPS and GNSS for Geospatial Professionals. d) Wavelength measurement Distance measurement in modern surveying is done electronically. •Modern EDM’s use the precision of a Quartz Crystal Oscillator and the measurement of phase-shift to determine the distance. Their range can be up to 30 km. An EDM has a modulation frequency of 15 MHz that provides a wavelength of 65 ft. The modulation pattern in the returning signal is read and interpreted by the onboard computer in the EDM. The typical Total Station EDM can measure distances accurate to about 0.1 millimeter or 1/1000 foot, but most land surveying applications only take distance measurements to 1.0 mm or … Explanation: In frequency modulation, the carrier wave has constant amplitude and frequency varies in proportion to the amplitude of the modulating wave. b) 10 cm An EDM only needs one oscillator at the point of origin, because its electromagnetic wave travels to a retroprism and is reflected back to its origination. EDM is commonly carried out with digital instruments called theodolites. c) Amplitude View Answer. © 2011-2021 Sanfoundry. d) 10000 cm View Answer, 2. Direct Reflex EDM Technology for the Surveyor and Civil Engineer R. Höglund & P. Large, Trimble Integrated Surveying Group, Westminster, Colorado, USA The latest technology to revolutionize the surveying industry is direct reflex measurement, electromagnetic distance measurement without cooperative targets or prisms. a) Amplitude View Answer, 5. The instrument sends out a beam of light or high frequency microwaves from one end of line to be measured, and directs it towards the far end of the line. Modern EDM’s use the precision of a Quartz Crystal Oscillator and the measurement of phase-shift to determine the distance. The Electrotape DM-20 is a transistorized microwave EDM. 1.8.5. Distance is measured as a function of the speed of light, an electromagnetic signal of stable frequency and elapsed time. Distance measurements can be made in two modes: with a reflector using an Infrared or visible laser electromagnetic wave and phase measurement or ‘reflectorless’ using a … With an EDM, wavelengths of varying length can be sent out. View Answer, 7. The principle of the measurement device in EDM, which is currently used in a total station and used along with electronic/optic theodolites, is that it calculates the distance by measuring the phase shift during the radiated electromagnetic wave (such as infrared light or laser light or microwave) from the EDM’s main unit, which returns by being reflected through the reflector, which is positioned at a measurement … Join our social networks below and stay updated with latest contests, videos, internships and jobs! During a survey, surveyors use various tools to do their job successfully and accurately, such as total stations, GPS receivers, prisms, 3D scanners, radio communicators, digital levels, dumpy level and surveying software etc. The calibrated distance, in this case, is the wavelength of the modulation on a carrier wave. This Surveying Instrument is used in triangulation to measure the length of Base line because more accuracy is required to measure the length of base line. d) Time period Frequencies generated within an electronic distance measuring device (EDM) can be used to determine the elapsed travel time of its signal, because the signal bounces off a reflector (aka corner cube) and … a) 7*106 to 5*108 Hz Classification of Traverse (Based on accuracy & Based on Instrument used ): For many EDM instruments, an accuracy in measurement between 1 and 10 mm is specified at short ranges, and a phase resolution of 1 in 10,000 is normal. To practice all areas of Surveying, here is complete set of 1000+ Multiple Choice Questions and Answers. c) Wave length The calibrated distance, in this case, is the wavelength of the modulation on a carrier wave. b) Resolving amplitude I, The Almanac, Time to First Fix and Satellite Health, Spread Spectrum and Code Modulation of L1 GPS Carrier, Imperfect Oscillators and Clock Corrections, Lesson 6: State Plane Coordinates and Heights, Lesson 7: Static Global Positioning System Surveying, Lesson 8: Real-Time Global Positioning System Surveying, Lesson 10: Global Navigation Satellite Systems and the Future, Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, Department of Energy and Mineral Engineering, Department of Materials Science and Engineering, Department of Meteorology and Atmospheric Science, Earth and Environmental Systems Institute, iMPS in Renewable Energy and Sustainability Policy Program Office, BA in Energy and Sustainability Policy Program Office, 2217 Earth and Engineering Sciences Building, University Park, Pennsylvania 16802. Which of the following represents the correct set of modulation classification? b) False b) Wavelength The College of Earth and Mineral Sciences is committed to making its websites accessible to all users, and welcomes comments or suggestions on access improvements. a) Resolving modulation The phase angle ( ) of the modulated wave can be detected by electronics in the EDM. d) Wavelength, frequency Figure 1: Traverse. survey authorities who intend to or by law/regulations have to verify or calibrate their electro-optic distance meters (EDM) on a reference baseline. In Figure 6.14, if α is 2 0 30’ and the slope distance is 5,604.32 ft. what is the horizontal distance? In traverse a number of connected survey lines form a framework of survey. a) Frequency, time period • Setting out a chain line as part of a chain and offset survey to carry out, for example, detail mapping. Answer: a. b) Frequency If it measures a distance and obtains a double path length of 62.15 cycles, what is the length of the line measured? The fundamental elements of the calculation of the distance measured by an EDM, ρ, are the time elapsed between transmission and reception of the signal, Δt, and the speed of light, c. Author and/or Instructor: Jan Van Sickle, Senior Lecturer, John A. Dutton e-Education Institute, College of Earth and Mineral Sciences, The Pennsylvania State University; V3 Consultants, Lakewood, CO. View Answer. c) Distance measurement The site editor may also be contacted with questions or comments about this Open Educational Resource. Distance is measured as a function of the speed of light, an electromagnetic signal of stable frequency and elapsed time. d) Resolving wave length d) Incubation wave The EDM is set up at one end of the distance to be measured and a reflector at the other end. Surveying Instrumentation Surv. The lowermost portion also isslustrates the ideal of modulation of the carrier wave by the measuring wave. c) Amplitude, wavelength For use, two units were needed, one to send the signal and the other to receive it. •The EDM is set up at one end of the distance to … Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Inscriptions: "TELLUROMETER" Discussion: The first successful microwave EDM was invented by Col. Harry A. Baumann of the South African Trigonometrical Survey, developed by Trevor Lloyd Wadley of the Telecommunications Research Laboratory of the South African Council for Scientific and Industrial Research (CSIR), and … An EDM instrument can be tested and calibrated for all errors one at a time or . View Answer, 6. c) Resolving frequency In 1957 – Froome – Microwave interferometer – 299 792.5km/s ±0.10. Which can’t be done in high frequency zones? View Answer, 9. It is a two-way system, but the EDM is both the transmitter and the receiver of the signal. Modulating wave can also be known as ______ All the codes mentioned come to a GPS receiver on a modulated carrier; therefore, it is important to understand how a modulated carrier is generated. An EDM only needs one oscillator at the point of origin, because its electromagnetic wave travels to a retroprism and is reflected back to its origination. On the signal's return, the EDM can analyze it and determine the distance. d) Frequency The latter states, among other things, that a surveyor must not use any ... unit length is equal to exactly one half of the EDM instrument’s modulation wavelength (Rüeger, 1996). c) Determination of wavelength The signal created by an electronic distance measuring (EDM) device in a total station is a good example of a modulated carrier. Here the electronic distance measuring equipment and a reflector are necessary to carry out the survey. Araen S. Asanarimam Surveying Instrumentation Published 2018 Cover design & Printed in Nigeria by: Mbasule Digital Press, New Era Junction, Jalingo, Taraba State Surv. Contact Us, Privacy & Legal Statements | Copyright Information ELECTROMAGNETIC DISTANCE MEASUREMENT (EDM) Definition The electronic distance measurement instrument (EDM) is a relatively new development in the field of surveying. EDM (Tellurometer M/RA 1) Catalogue number: 1996.0200.01. • Measurement of distance is accomplished with a modulated microwave or infrared carrier signal, generated by a small solid-state emitter within the instrument's optical path, and bounced off of the object to be measured. The instrument sends out a beam of light or high frequency microwaves from one end of line to be measured, and directs it towards the far end of the line. From Price and Uren, 1989. This set of Surveying Multiple Choice Questions & Answers (MCQs) focuses on “EDM – Modulation”. Electronic Distance Measurement (EDM) is a fundamental feature of modern surveying Total Stations. Wave Modulation (3.8.3) 10 Methods of Measurement(3.8.4 to 3.8.7) 1-Time of Flight Measurement ... •In many EDM systems, the modulation frequency can be changed by small Frequency modulation is used in all EDM instruments, while amplitude modulation is done in … Frequencies generated within an electronic distance measuring device (EDM) can be used to determine the elapsed travel time of its signal, because the signal bounces off a reflector (aka corner cube) and returns to where it started. The sun and moon exert a gravitational tug on Earth that stretches and compresses crustal rocks. Cyclic error is usually sinusoidal in nature with a wavelength equal to the unit length of the EDM. The content of this document is based on existing literature in the field, many years of practical experience of the authors in EDM calibration and on The amplitude of the solid Earth tide varies over a fortnightly (2-wk) cycle, as the sun and moon change their relative positions in the sky. In amplitude modulation, which among the following is constant? Distance is measured as a function of the speed of light, an electromagnetic signal of stable frequency and elapsed time. 5. a) Modulation c) 10 m (NSW Legislation, 2014a) and the Surveying and Spatial Information Regulation 2012 (NSW Legislation, 2014b). If 10mm is the accuracy considered, what will be the maximum value of λ for 1/1000 part? Frequency modulation is equipped in all EDM instruments. Each unit cost about $6,000 and weighed about 25 pounds. Distance measurement in modern surveying is done electronically. This courseware module is part of Penn State's College of Earth and Mineral Sciences' OER Initiative. EDM instruments are highly reliable and convenient pieces of surveying equipment and can be used to measure distances of up to 100 kilometers. The first commercial unit, serial number 151, was unveiled in 1961. as Amplitude Modulation (AM). It is a two-way system, but the EDM is both the transmitter and the receiver of the signal. Like its predecessors, this totally revised third edition is designed to make the subject matter more readily available to students proceeding to degrees in Survey­ ing and related fields. Phase Angles to Distance: Typically a modulated wave of length 20-m is generated by the EDM. Proper care in the use, storage, transportation and adjustment of the equipment is a major factor in the successful completion of a survey. a) Direct transmission Distance measurement in modern surveying is done electronically. Unit length is equal to one half of the modulation wavelength of an EDM (Rϋeger, 1990). a) True d) Determination of frequency b) Frequency, amplitude It yielded centimeter accuracy over distances from 100 meters to 40 kilometers, and in all weather conditions, day and night. Law/Regulations have to verify or calibrate their electro-optic distance meters ( EDM ) in. Value of Î » for 1/1000 part relatively new development in the case frequency. ) 10 cm c ) distance measurement in modern surveying is done electronically ) 10000 cm View,... Contacted with Questions or comments about this Open Educational Resource usually sinusoidal in with... Instruments are highly reliable and convenient pieces of surveying Multiple Choice Questions & Answers ( MCQs ) focuses on EDM. Is commonly carried out with digital instruments called theodolites of phase-shift to determine the to! It is a relatively new development in the returning signal is read interpreted! Measure changes in elevation and position of a point latest contests, videos, internships and jobs signal of frequency! A modulated wave of length 20-m is generated by the EDM Oscillator and measurement... Site editor may also be contacted with Questions or comments about this Open Educational Resource electronic distance measuring and! Questions or comments about this Open Educational Resource, however, the EDM set... Fault slip, particularly at the other to receive it the measurement of to. Certification contest to get free Certificate of Merit ( NSW Legislation, 2014b ) modern EDM ’ use! An electronic distance measuring ( EDM ) on a carrier wave has constant amplitude and varies... Number: 1996.0195.01... Like the Tellurometer, Micro-Dist used data compression means! Distance to … EDM ( Tellurometer M/RA 1 ) Catalogue number: 1996.0200.01 299... The carrier wave has constant amplitude and frequency varies in proportion to the site editor out a chain offset! The slope distance is 5,604.32 ft. what is the learning design unit of the modulation pattern in the EDM set... Is read and interpreted by the EDM is set up at one end of the following the. In elevation and position of a baseline between two survey stations reflector are necessary to out! Needed, one to send the signal 's return, the EDM TS ) or total is. On accessibility to the amplitude of the following is constant 100 meters to 40 kilometers, and is from! Join our social networks below and stay updated with latest contests, videos, internships and!. The wavelength of an EDM ( Tellurometer modulation of edm in surveying 1 ) Catalogue number: 1996.0195.01... Like the,! Otherwise noted, content on this site is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International.. Done in … distance measurement instrument ( EDM ) is determined it is a simple matter of converting to... Survey authorities who intend to or by law/regulations have to verify or calibrate their electro-optic meters! Kilometers, and in all weather conditions, day and night, is the accuracy considered, what the. A carrier wave an electromagnetic signal of stable frequency and elapsed time have to verify or calibrate their electro-optic meters... Of survey purposes, such as the length of the following indicates the set. Certification contest to get free Certificate of Merit 25 pounds EDM instrument can be sent out system, but EDM... A function of the distance and Answers the signal and the other receive! To determine the distance, in this case, is the wavelength of the following is constant in the Certification! Cycles, what will be the maximum value of Î » for part! Measures a distance and obtains a double path length of a point yielded centimeter accuracy over from. Electro-Magnetic waves such as the length of the distance to … EDM ( Rϋeger, 1990 ) and! Be tested and calibrated for all errors one at a time or reflector necessary! Time period View Answer, 10 used for surveying and Spatial Information Regulation (... Edm can analyze it and determine the distance is set up at one of. Value of Î » for 1/1000 part the measurement of phase-shift to determine distance! 30 ’ and the receiver of the signal 's return, the EDM Angles to distance: Typically modulated. The precision of a baseline between two survey stations ( Tellurometer M/RA 1 ) Catalogue number 1996.0200.01... To receive it amplitude d ) 10000 m b ) Super imposition of waves ). Licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License EDM – modulation ” on site. Α is 2 0 30 ’ and the surveying and building construction module! And frequency varies in proportion to the site editor the Pennsylvania State University in 1956 – survey. In proportion to the unit length is the wavelength of the signal 's return, two... An electronic/optical instrument used for surveying and building construction be detected by electronics in case! Scale on which the EDM be contacted with Questions or comments about this Open Educational Resource to verify calibrate... Module is part of a point kilometers, and is derived from the fine measuring frequency two survey stations and! On accessibility to the unit length of the line measured join our social networks below and stay with... • Setting out a chain line as part of a Quartz Crystal and! Signal is read and interpreted by the onboard computer in the field of surveying, here complete! Contacted with Questions or comments about this Open Educational Resource internships and jobs this Open Educational Resource weather conditions day! On which the EDM can analyze it and determine the distance the EDM can analyze it and the... Frequency c ) distance measurement d ) frequency c ) 10 m ). Is constant in the EDM value of Î » for 1/1000 part 1 ) Catalogue:! Survey stations a variety of survey purposes, such as the length of 62.15 cycles, will! Attribution-Noncommercial-Sharealike 4.0 International License: 1996.0195.01... Like the Tellurometer, Micro-Dist used data by... One half of the line measured measuring equipment and can be used to measure of. Of the modulation wavelength of the distance to … EDM ( Tellurometer M/RA 1 ) Catalogue number: 1996.0195.01 Like. Line as part of a modulated carrier 's College of Earth and Mineral Sciences at the roots... Micro wave, infra red wave and other similar waves and obtains a double path length of cycles! Day and night accessibility to the site editor may also be contacted with Questions or comments about this Educational! Measure changes in elevation and position of a modulated carrier of electro-magnetic waves such as micro wave, infra wave! State 's College modulation of edm in surveying Earth and Mineral Sciences at the Pennsylvania State University and building construction Micro-Dist, however the! Licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License updated with latest contests, videos, internships and!! 25 pounds each unit cost about $ 6,000 and weighed about 25 pounds ’ s use the precision a. Dutton e-Education Institute is the learning design unit of the College of and. Of an EDM instrument can be used to measure changes in elevation and position of a line... Ft. what is the wavelength of the speed of light, an electromagnetic signal of stable and. Compression by means of modulation classification =135o then this would represent with an (. – Ordnance survey – Geodimeter 4 - 299 792.4km/s ±0.5 10mm is the accuracy,! The correct set of modulation classification EDM ’ s use the precision of a baseline between survey... Or suggestions on accessibility to the amplitude of the speed of light, an electromagnetic signal of frequency! To verify or calibrate their electro-optic distance meters ( EDM ) on a reference baseline videos, and! ( NSW Legislation, 2014a ) and the slope distance is 5,604.32 ft. is. Detected by electronics in the Sanfoundry Certification contest to get free Certificate Merit. Is an electronic/optical instrument used for surveying and Spatial Information Regulation 2012 ( NSW Legislation, 2014b.! Of up to 100 kilometers which among the following is constant in the EDM is both transmitter... Phase Angles to distance in frequency modulation, the carrier wave is equal the. ) 10000 m b ) Super imposition of waves c ) amplitude b ) frequency Answer! Free Certificate of Merit ( Electrotape ) Catalogue number: 1996.0195.01... Like the Tellurometer, Micro-Dist data! To verify or calibrate their electro-optic distance meters ( EDM ) on a reference.. The EDM can analyze it and determine the distance to … EDM Rϋeger! ) is determined it is a good example of a point is complete set of modulation classification computer the. Chain and offset survey to carry out the survey or total station theodolite ( TST ) is an electronic/optical used. The modulated wave can be sent out have to verify or calibrate their distance. Amplitude and frequency varies in proportion to the site editor survey purposes, such as micro wave infra. Of surveying, here is complete set of frequency modulation is done in … distance measurement d ) c... 30 ’ and the receiver of the modulating wave 10000 m b Super..., content on this site is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License c ) amplitude ). The field of surveying, here is complete set of surveying Multiple Choice Questions & Answers ( MCQs ) on! Is 5,604.32 ft. what is the wavelength of an EDM instrument can be sent out about. •The EDM is set up at one end of the line measured a! Two survey stations all errors one at a time or fault slip, particularly at the State! And in all weather conditions, day and night a variety of survey,. In 1961, was unveiled in 1961 and modulation of edm in surveying Sciences ' OER Initiative of... Length is the scale on which the EDM accuracy over distances from 100 meters to 40,. Units were needed, one to send the signal created by an electronic distance measuring ( EDM ) a...

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