193 research outputs found
Special studies of AROD systems, concepts and designs Final report
Design and evaluation of development model for airborne range and orbit determination syste
Radio communications study on noise threshold reduction. Task 3 - Oscillator stability in a tracking system Final report
Oscillator stability in range and range rate tracking syste
Multipath performance of a TDRS system employing wideband FM VHF signals
An approximate theoretical analysis is presented for the effects of specular reflection multipath on the performance of a one-way tracking and data relay satellite-to-user link. The analysis pertains to the wideband FM system employing a sinusoidal subcarrier to achieve spectrum spreading. Bounds on multipath effects are derived for receivers with and without limiters and for data modulated on the carrier or the subcarrier. For data modulation, performance is evaluated in terms of an additive lowpass signal at the data detection filter. Doppler and range tracking performance is evaluated in terms of root-mean-square (RMS) error of carrier frequency in a carrier PLL and rms phase jitter in a subcarrier PLL
SNR behavior of coherent phase demodulators. Radio communications study on noise threshold reduction Final report
Signal to noise ratio analysis at outputs of three coherent phase detectors for radio noise threshold reduction stud
Multipath signal model development
The development and use of mathematical models of signals received through the multipath environmental of a TDRS-to-user spacecraft link and vice versa are discussed. The TDRS (tracking and data relay satellite) will be in synchronous orbit. The user spacecraft will be in a low altitude orbit between 200 and 4000 km
Part I - Application of ultra-stable oscillators to one-way ranging systems. Part II - Fluctuation spectra of ultra- stable oscillators - Measurement and estimation Final report
Application of ultrastable oscillators to one-way ranging systems - Measurement technique for determining phase fluctuation spectrum of highly stable oscillator
Special studies of AROD system concepts and designs
Signal processing techniques for range and range rate measurements in airborne range and orbit determinatio
Intermodulation distortion from receiver non-linear phase characteristics Final report
Computation of intermodulation distortion levels produced by telemetry system predetection filte
Simulation of the TDRS multipath environment
Design principles and implementation methods are discussed for simulating the propagation path between a tracking and data relay satellite and a mission spacecraft. The emphasis is on multipath and Doppler simulation but additive disturbances are also considered. The recommended form of the simulator is fed separately with the unmodulated carrier, the unmodulated subcarriers (or spread-spectrum components) and the data signals. The perturbations are also introduced separately; then successive modulation operations are performed. The simulator is segmented into elements that perform the various functions of direct and specular multipath, diffuse fading, Doppler shift and delay spread. Delay spreads are realized by discrete delays operating on baseband signals. Doppler simulation and ionospheric or diffuse multipath fading are applied to individual paths before or after modulation of the carrier by delayed baseband signals. Block diagrams are presented on how the different elements are combined to create a complete channel simulator
RANCANG BANGUN ALAT BANTU PENGGORES UNTUK PEMBAGI LUBANG PADA FLANGE
Laporan ini berjudul Rancang Bangun alat bantu penggores untuk pembagi lubang pada flange. Laporan akhir ini adalah laporan mengenai suatu langkah menginovasi alat bantu tersebut hanya bisa melakukan pengukuran flange 3inch – 5inch alat ini diharapkan dapat memberikan kemudahan dan manfaat untuk mendapatkan effisien. Dalam proses pembuatannya Rancang Bangun alat bantu ini menggunakan mesin milling, mesin bubut, mesin bor, dan alat perkakas kerja bangku lainnya. Alat ini masih terdapat banyak kekurangan, untuk itu masih perlu dilakukan beberapa modifikasi agar fungsi kerja alat ini dapat bekerja lebih optimal
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