Pub Date : 1965-06-01DOI: 10.1109/TSET.1965.5009645
S. Gupta, R. J. Solem
The advantages of a third-order phase-locked loop for FM television is considered here. The bandwidth is maintained small and since the operation is generally at frequencies small compared to the bandwidth, the criterion is to keep error as small as possible in this frequency range. A study is made by comparing second- and third-order phase-locked loops designed from Wiener filtering theory, as advanced by Jaffe and Rechtin [1]; considerable improvement in error is evident using a third-order phase-locked loop for frequencies up to about one-twentieth of the bandwidth. To improve the error function still further, a new error-function criterion is established whereby the error at the lower frequencies of interest is minimized. Such a minimum is obtained for both second- and third-order phase-locked loops. Transfer function behavior, transient response, and root locus plots of all these cases are given to emphasize the advantages of this new design. Error is reduced up to six decibels with no degradation of transient response, overshoot, etc. It is shown that the bandwidth can be reduced without increasing the error if the filter designed by this new criterion is used.
{"title":"Optimum Filters for Second- and Third-Order Phase-Locked Loops by an Error-Function Criterion","authors":"S. Gupta, R. J. Solem","doi":"10.1109/TSET.1965.5009645","DOIUrl":"https://doi.org/10.1109/TSET.1965.5009645","url":null,"abstract":"The advantages of a third-order phase-locked loop for FM television is considered here. The bandwidth is maintained small and since the operation is generally at frequencies small compared to the bandwidth, the criterion is to keep error as small as possible in this frequency range. A study is made by comparing second- and third-order phase-locked loops designed from Wiener filtering theory, as advanced by Jaffe and Rechtin [1]; considerable improvement in error is evident using a third-order phase-locked loop for frequencies up to about one-twentieth of the bandwidth. To improve the error function still further, a new error-function criterion is established whereby the error at the lower frequencies of interest is minimized. Such a minimum is obtained for both second- and third-order phase-locked loops. Transfer function behavior, transient response, and root locus plots of all these cases are given to emphasize the advantages of this new design. Error is reduced up to six decibels with no degradation of transient response, overshoot, etc. It is shown that the bandwidth can be reduced without increasing the error if the filter designed by this new criterion is used.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124360171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1965-06-01DOI: 10.1109/TSET.1965.5009648
R. Tausworthe
A closed-loop range-locked radar system developed by the Jet Propulsion Laboratory has recently had great success range tracking the planet Venus. It has provided measurements to the planetary mean-tracking point with peak minute-to-minute variations less than 2.25 to 3 Km in range. Over a one-hour tracking period, a mean tracking point can be determined to 0.5 km. A scattering-law calibration of the planet is made each day, measuring the mean-tracking-point-to-planetary-surface distance to within 3 km (nominal). The subearth point-to-radar distance is thus measured to a nominal accuracy of 3.5 km. Tracking behaves as a first-order linear ``range-locked'' loop with ephemeris aid, and is practically calibration free. Data obtained during the 1964 conjunction showed that the ephemeris not only contained a range error, but also a range-rate error of 18 km per day. Deviations from this rate correspond to surface features whose height can be estimated. Such data will be invaluable in determining, to a greater degree of accuracy than ever before attainable, the orbital constants of the earth and Venus.
{"title":"A Precision Planetary Range-Tracking Radar","authors":"R. Tausworthe","doi":"10.1109/TSET.1965.5009648","DOIUrl":"https://doi.org/10.1109/TSET.1965.5009648","url":null,"abstract":"A closed-loop range-locked radar system developed by the Jet Propulsion Laboratory has recently had great success range tracking the planet Venus. It has provided measurements to the planetary mean-tracking point with peak minute-to-minute variations less than 2.25 to 3 Km in range. Over a one-hour tracking period, a mean tracking point can be determined to 0.5 km. A scattering-law calibration of the planet is made each day, measuring the mean-tracking-point-to-planetary-surface distance to within 3 km (nominal). The subearth point-to-radar distance is thus measured to a nominal accuracy of 3.5 km. Tracking behaves as a first-order linear ``range-locked'' loop with ephemeris aid, and is practically calibration free. Data obtained during the 1964 conjunction showed that the ephemeris not only contained a range error, but also a range-rate error of 18 km per day. Deviations from this rate correspond to surface features whose height can be estimated. Such data will be invaluable in determining, to a greater degree of accuracy than ever before attainable, the orbital constants of the earth and Venus.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"274 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114482604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1965-06-01DOI: 10.1109/TSET.1965.5009647
G. Pelchat
Mathematical expressions are obtained for FM and PM power spectra when the modulating waveform is a constantrate random sequence of nonoverlapping pulses with arbitrary shape and amplitude distribution. These expressions essentially reduce the computation of power spectrum to the computation of the average energy spectrum of a section of the wave only two pulses in length. The results are applied to the special PAM/FM case where the modulating pulses have a rectangular shape and uniformly distributed amplitude. Spectra are plotted for several values of the deviation ratio. Results are also given for the much simpler case of binary PAM/PM for arbitrary phase deviations.
{"title":"Power Spectrum of PAM/FM and PAM/PM","authors":"G. Pelchat","doi":"10.1109/TSET.1965.5009647","DOIUrl":"https://doi.org/10.1109/TSET.1965.5009647","url":null,"abstract":"Mathematical expressions are obtained for FM and PM power spectra when the modulating waveform is a constantrate random sequence of nonoverlapping pulses with arbitrary shape and amplitude distribution. These expressions essentially reduce the computation of power spectrum to the computation of the average energy spectrum of a section of the wave only two pulses in length. The results are applied to the special PAM/FM case where the modulating pulses have a rectangular shape and uniformly distributed amplitude. Spectra are plotted for several values of the deviation ratio. Results are also given for the much simpler case of binary PAM/PM for arbitrary phase deviations.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126650537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1965-06-01DOI: 10.1109/TSET.1965.5009649
W. Postl
{"title":"Power Spectrum of a Random PCM-FM Wave","authors":"W. Postl","doi":"10.1109/TSET.1965.5009649","DOIUrl":"https://doi.org/10.1109/TSET.1965.5009649","url":null,"abstract":"","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127361119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1965-06-01DOI: 10.1109/TSET.1965.5009646
W. Kendall
In this paper we consider the problem of using signals received at three or four antennas to estimate the direction from which radio-frequency (RF) radiation is arriving. Though the results are couched in the terminology of angle measurements, they are applicable to any ambiguous measurements for which the number of ambiguities is inversely proportional to the accuracy. For an interferometric system the effect of receiver noise is examined. Then the optimum way to process the received waveforms, and the best spacing for the antennas, is determined. Next, signal-to-noise ratio (SNR) requirements are determined which must be met to insure that, with a given probability, the final unambiguous measurement is not in error by more than some specified amount. Finally, a comparison is made between a system which uses unambiguous measurements and a system which uses ambiguous measurements and then resolves the ambiguities.
{"title":"Unambiguous Accuracy of an Interferometer Angle-Measuring System","authors":"W. Kendall","doi":"10.1109/TSET.1965.5009646","DOIUrl":"https://doi.org/10.1109/TSET.1965.5009646","url":null,"abstract":"In this paper we consider the problem of using signals received at three or four antennas to estimate the direction from which radio-frequency (RF) radiation is arriving. Though the results are couched in the terminology of angle measurements, they are applicable to any ambiguous measurements for which the number of ambiguities is inversely proportional to the accuracy. For an interferometric system the effect of receiver noise is examined. Then the optimum way to process the received waveforms, and the best spacing for the antennas, is determined. Next, signal-to-noise ratio (SNR) requirements are determined which must be met to insure that, with a given probability, the final unambiguous measurement is not in error by more than some specified amount. Finally, a comparison is made between a system which uses unambiguous measurements and a system which uses ambiguous measurements and then resolves the ambiguities.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127943293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1965-03-01DOI: 10.1109/TSET.1965.5009629
J. Holmes
An analysis of a coherent two-way (transponder) Doppler communication system composed of a ground transmitter, a spacecraft transponder, and a ground receiver has been made to determine the effects of VCO phase and thermal phase noise at the ground receiver output (See Fig. 2). This system is typical of those used on lunar and planetary space programs. The analysis shows that the phase noise contribution of the ground receiver's VCO is inversely proportional to the ground receiver's noise bandwidth [See (15)]. Further it has been shown that the spacecraft VCO phase noise, spacecraft thermal phase noise, and ground receiver thermal phase noise are all functions of the ratio of transponder-to-ground-receiver noise bandwidths [See (13), (4) and (5)]. All the relationships were derived using complex integration techniques.
{"title":"A Consideration of VCO and Thermal Phase Noise in a Coherent Two-Way Doppler Communication System","authors":"J. Holmes","doi":"10.1109/TSET.1965.5009629","DOIUrl":"https://doi.org/10.1109/TSET.1965.5009629","url":null,"abstract":"An analysis of a coherent two-way (transponder) Doppler communication system composed of a ground transmitter, a spacecraft transponder, and a ground receiver has been made to determine the effects of VCO phase and thermal phase noise at the ground receiver output (See Fig. 2). This system is typical of those used on lunar and planetary space programs. The analysis shows that the phase noise contribution of the ground receiver's VCO is inversely proportional to the ground receiver's noise bandwidth [See (15)]. Further it has been shown that the spacecraft VCO phase noise, spacecraft thermal phase noise, and ground receiver thermal phase noise are all functions of the ratio of transponder-to-ground-receiver noise bandwidths [See (13), (4) and (5)]. All the relationships were derived using complex integration techniques.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1965-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116731149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1965-03-01DOI: 10.1109/TSET.1965.5009630
W. Lindsey
This paper presents detailed results on the relative merits of encoding blocks of binary digits into a set of equiprobable, equal energy, orthogonal signals each containing n bits of information. During a time interval of T seconds, one signal from this set is selected and transmitted over the ``Rician'' channel, further perturbed by additive white Gaussian noise and noncoherently detected at the receiver by matched filters and follow-up envelope detectors. Word and bit error probabilities (and bounds on these) are graphically illustrated for various degrees of coding and for various forms of the channel model. Particular emphasis is placed on the Gaussian channel. Special cases of Viterbi's results for coded phase-coherent communications are compared with those obtained in this paper. Bandwidth considerations are also discussed. The results are useful to the engineer who is faced with the problem of designing coded communication systems where power is limited to the point that phase coherence cannot be established at the receiver. Typical examples are space communications where it is desired to telemeter scientific data from small scientific satellites or space probes or for scatter-channel links which are to be used for relaying data between two widely separated points on the earth.
{"title":"Coded Noncoherent Communications","authors":"W. Lindsey","doi":"10.1109/TSET.1965.5009630","DOIUrl":"https://doi.org/10.1109/TSET.1965.5009630","url":null,"abstract":"This paper presents detailed results on the relative merits of encoding blocks of binary digits into a set of equiprobable, equal energy, orthogonal signals each containing n bits of information. During a time interval of T seconds, one signal from this set is selected and transmitted over the ``Rician'' channel, further perturbed by additive white Gaussian noise and noncoherently detected at the receiver by matched filters and follow-up envelope detectors. Word and bit error probabilities (and bounds on these) are graphically illustrated for various degrees of coding and for various forms of the channel model. Particular emphasis is placed on the Gaussian channel. Special cases of Viterbi's results for coded phase-coherent communications are compared with those obtained in this paper. Bandwidth considerations are also discussed. The results are useful to the engineer who is faced with the problem of designing coded communication systems where power is limited to the point that phase coherence cannot be established at the receiver. Typical examples are space communications where it is desired to telemeter scientific data from small scientific satellites or space probes or for scatter-channel links which are to be used for relaying data between two widely separated points on the earth.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1965-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124580162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1965-03-01DOI: 10.1109/TSET.1965.5009637
D. Childers
{"title":"Noise in Digital-to-Analog Conversion Due to Bit Errors","authors":"D. Childers","doi":"10.1109/TSET.1965.5009637","DOIUrl":"https://doi.org/10.1109/TSET.1965.5009637","url":null,"abstract":"","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1965-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133518573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1965-03-01DOI: 10.1109/TSET.1965.5009631
L. Mertens, R. H. Tabeling
The Air Force Eastern Test Range (ETR) is, in essence, a huge laboratory extending from the Florida mainland to the Indian Ocean. It is instrumented to collect, record, analyze and communicate data for missile and space missions. This is achieved through a variety of highly sophisticated electronic and optical techniques. It is the purpose of this paper to describe briefly some of this primary instrumentation which provides the highly precise metric data used in direct support of the operational mission, for Range safety and for postflight evaluation. The instrumentation and data accuracy problems will be explored together with the current methods of approach. General categories of errors will be defined, and the applications of error models and error budgets to the controlling of instrumentation accuracies will be presented. Methods of combining outputs of various instrumentation systems will be discussed with reference to the best estimate of trajectory. The general problem of instrumentation calibration is also considered, including the experimental design and the type of tests employed. The basic causes of accuracy degradation in the instrumentation systems are reviewed, including errors introduced in data handling and processing.
{"title":"Tracking Instrumentation and Accuracy on the Eastern Test Range","authors":"L. Mertens, R. H. Tabeling","doi":"10.1109/TSET.1965.5009631","DOIUrl":"https://doi.org/10.1109/TSET.1965.5009631","url":null,"abstract":"The Air Force Eastern Test Range (ETR) is, in essence, a huge laboratory extending from the Florida mainland to the Indian Ocean. It is instrumented to collect, record, analyze and communicate data for missile and space missions. This is achieved through a variety of highly sophisticated electronic and optical techniques. It is the purpose of this paper to describe briefly some of this primary instrumentation which provides the highly precise metric data used in direct support of the operational mission, for Range safety and for postflight evaluation. The instrumentation and data accuracy problems will be explored together with the current methods of approach. General categories of errors will be defined, and the applications of error models and error budgets to the controlling of instrumentation accuracies will be presented. Methods of combining outputs of various instrumentation systems will be discussed with reference to the best estimate of trajectory. The general problem of instrumentation calibration is also considered, including the experimental design and the type of tests employed. The basic causes of accuracy degradation in the instrumentation systems are reviewed, including errors introduced in data handling and processing.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1965-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116846135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1965-03-01DOI: 10.1109/TSET.1965.5009635
K. Hiroshige
This paper presents a simple technique for improving the pull-in capability of phase-lock loops. This technique, called derived rate rejection or DRR, differs from those which use an external AFC loop in simplicity of implementation and design rationale, although the end result is the same. If, as is usually the case, a coherent detector accompanies the phase-lock loop, the implementation of the DRR technique requires only the addition of a switch. The switching logic results from a superficial consideration of the nonlinear equation for the phase-lock loop and its solution in the phase plane. The switch does not affect the normal behavior of the loop after lock has been attained. Results of computer studies show the improvement realizable for the following configurations: 1) Proportional-plus-integral control. 2) Proportional-plus-imperfect integral control. For an initial frequency error of five times the linearized phase lock-loop natural frequency, the improvement in pull-in time is a factor of two. For an initial frequency error of ten times the phase-lock loop natural frequency, the improvement in pull-in time is a factor of ten.
{"title":"A Simple Technique for Improving the Pull-in Capability of Phase-Lock Loops","authors":"K. Hiroshige","doi":"10.1109/TSET.1965.5009635","DOIUrl":"https://doi.org/10.1109/TSET.1965.5009635","url":null,"abstract":"This paper presents a simple technique for improving the pull-in capability of phase-lock loops. This technique, called derived rate rejection or DRR, differs from those which use an external AFC loop in simplicity of implementation and design rationale, although the end result is the same. If, as is usually the case, a coherent detector accompanies the phase-lock loop, the implementation of the DRR technique requires only the addition of a switch. The switching logic results from a superficial consideration of the nonlinear equation for the phase-lock loop and its solution in the phase plane. The switch does not affect the normal behavior of the loop after lock has been attained. Results of computer studies show the improvement realizable for the following configurations: 1) Proportional-plus-integral control. 2) Proportional-plus-imperfect integral control. For an initial frequency error of five times the linearized phase lock-loop natural frequency, the improvement in pull-in time is a factor of two. For an initial frequency error of ten times the phase-lock loop natural frequency, the improvement in pull-in time is a factor of ten.","PeriodicalId":153922,"journal":{"name":"IEEE Transactions on Space Electronics and Telemetry","volume":"900 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1965-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116393218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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