Algorithm of Time and Frequency Remote Calibration System of SNSU-BSN

National Measurement Standards-National Standardization Agency of Indonesia (SNSU-BSN) as the National Metrology Institute of Indonesia has provided time and frequency calibration services for customers. Time and frequency equipment should be calibrated to traceable to the SI units. The calibration process can be carried out in a calibration laboratory. However, some measuring devices cannot be sent to the calibration laboratory. One of the devices that cannot be sent to the calibration laboratory is Cesium atomic clock. It must be calibrated to get the time difference with the local coordinated universal time (UTC), namely UTC(IDN). Therefore, to calibrate the Cesium atomic clock, a remote calibration method is needed. The remote system is also intended to conduct the calibration more effectively and efficiently. This method requires two Global Positioning System (GPS) receiver devices placed on the client-side and a calibration laboratory. For this reason, an algorithm for remote calibration has been developed. The algorithm has been tested to calibrate Cesium-3 of SNSU-BSN against UTC(IDN). The time difference between Cesium-3 and UTC(IDN) was 5.8 microseconds by using the algorithm. Based on the algorithm that has been built, it was concluded that the algorithm can be used to perform remote calibration for the related customer.

Download Full-text

A low complexity digital frequency calibration with high jitter immunity for ultra-low-power oscillators

Advances in Radio Science ◽

10.5194/ars-17-145-2019 ◽

2019 ◽

Vol 17 ◽

pp. 145-150

Author(s):

Markus Scholl ◽

Ralf Wunderlich ◽

Stefan Heinen

Keyword(s):

Low Power ◽

Communication Systems ◽

Calibration Method ◽

Low Complexity ◽

Frequency Stability ◽

Wireless Communication Systems ◽

Ultra Low Power ◽

Wireless Transceiver ◽

Digital Frequency ◽

Frequency Calibration

Abstract. This paper presents a highly efficient digital frequency calibration method for ultra-low-power oscillators in wireless communication systems. This calibration method locks the ultra-low-power oscillator's output frequency to the reference clock of the wireless transceiver during its send- and receive-state to achieve frequency stability over process variation and temperature drifts. The introduced calibration scheme offers high jitter immunity and short locking periods overcoming frequency calibration errors for typical ultra-low-power oscillator's by utilizing non-linear segmented feedback levels. In measurements the proposed calibration method improves the frequency stability of an ultra-low-power 32 kHz oscillator from 53 to 10 ppm ∘C−1 over a wide temperature range for temperature drifts of less than 1 ∘C s−1 with an estimated power consumption of 185 nW while coping with relocking periods of 7 ms.

Download Full-text

A Bandwidth and Frequency Calibration Method for OOK UWB-IR Transmitter with High Energy Efficiency

Journal of Circuits System and Computers ◽

10.1142/s0218126620501376 ◽

2019 ◽

Vol 29 (09) ◽

pp. 2050137

Author(s):

Shengxi Diao ◽

Fujiang Lin ◽

Yuanjin Zheng

Keyword(s):

Power Efficiency ◽

Average Power ◽

Calibration Method ◽

High Energy ◽

Impulse Radio ◽

Ultra Wideband ◽

Lc Oscillator ◽

Data Rates ◽

Pvt Variations ◽

Frequency Calibration

In this paper, an offline bandwidth and frequency calibration method for an on–off LC oscillator-based ultra-wideband impulse radio (UWB-IR) transmitter is presented. Implemented in 0.18-[Formula: see text]m CMOS, the offline calibration circuits consume very little power. This allows the transmitter to consume an ultra-low average power of 319[Formula: see text][Formula: see text]W over 3–5[Formula: see text]GHz at 2[Formula: see text]Mbps. The calibration is critical to ensure the FCC spectral mask compliance despite the process–voltage–temperature (PVT) variations. The transmitter can deliver a large differential output swing of 1.8–3[Formula: see text]V to a 100-[Formula: see text] load with minimal power efficiency of 7% at different data rates (2–30[Formula: see text]Mbps). It is suitable for WPAN application with localization and positioning capabilities.

Download Full-text

Re-Evaluation of Calibration and Measurement Capabilities of Pitch Calibration Systems Designed by Using the Diffraction Method

International Journal of Automation Technology ◽

10.20965/ijat.2017.p0691 ◽

2017 ◽

Vol 11 (5) ◽

pp. 691-698

Author(s):

Ichiko Misumi ◽

Jun-ichiro Kitta ◽

Ryosuke Kizu ◽

Akiko Hirai ◽

◽

...

Keyword(s):

Semiconductor Industry ◽

Diffraction Method ◽

Reference Value ◽

Critical Dimension ◽

National Metrology Institute ◽

Calibration Laboratory ◽

Long Term Stability ◽

Calibration And Measurement Capabilities ◽

Electron Microscopes ◽

Measurement Capabilities

One-dimensional grating is one of the most important standards that are used to calibrate magnification of critical-dimension scanning electron microscopes (CD-SEMs) in the semiconductor industry. Long-term stability of pitch calibration systems is required for the competence of testing and calibration laboratories determined in ISO/IEC 17025:2005. In this study, calibration and measurement capabilities of two types of pitch calibration systems owned by a calibration laboratory are re-evaluated through comparison to a reference value and its expanded uncertainty given by a metrological atomic force microscope (metrological AFM) at National Metrology Institute of Japan (NMIJ), AIST. The calibration laboratory’s pitch calibration systems are designed by using the diffraction method (optical and X-ray).

Download Full-text

Mid-Infrared Sources Using Dye Lasers in KTiOAsO4 and LiIO3

Applied Spectroscopy ◽

10.1366/0003702963905745 ◽

1996 ◽

Vol 50 (6) ◽

pp. 790-794 ◽

Cited By ~ 2

Author(s):

A. H. Kung ◽

Suli Fei ◽

H. L. Strauss

Keyword(s):

Nd:Yag Laser ◽

Second Harmonic ◽

Damage Threshold ◽

Calibration Method ◽

Laser Damage Threshold ◽

Infrared Source ◽

Yag Lasers ◽

Frequency Calibration ◽

Infrared Sources ◽

532 Nm

A coherent infrared source tunable from 3.4 to 5.3 μm has been constructed by difference-frequency mixing of the second harmonic of a Q-switched Nd:YAG laser and a pulsed dye laser using the new crystal KTiOAsO4 (KTA). A peak power of >50 kW and pulse energy of >250 μJ are measured at 4.4 μm. The results are compared with mixing in LiIO3. For a low-power Nd:YAG laser that produces 200 mJ of 532-nm radiation, the infrared power is similar for the two crystals. For high-power YAG lasers, calculation shows that commercial KTA crystals can produce over 10 mJ of IR power in the absence of absorption loss. The laser damage threshold of KTA at 532 nm is determined to be 300 ± 30 MW/cm2. Both the maximum IR power and the damage threshold are several times higher for KTA than for LiIO3. A simple frequency calibration method is described.

Download Full-text

Star-Based Calibration of the Installation Between the Camera and Star Sensor of the Luojia 1-01 Satellite

Remote Sensing ◽

10.3390/rs11182081 ◽

2019 ◽

Vol 11 (18) ◽

pp. 2081 ◽

Cited By ~ 1

Author(s):

Zhichao Guan ◽

Yonghua Jiang ◽

Jingyin Wang ◽

Guo Zhang

Keyword(s):

High Frequency ◽

Road Network ◽

Reference Data ◽

Calibration Method ◽

Star Sensor ◽

Control Points ◽

Positioning Accuracy ◽

Ground Control Points ◽

Position Data ◽

Frequency Calibration

Ground control points (GCPs) are generally used to calibrate the installation between the camera and star sensor of a satellite in orbit and improve the geometric positioning accuracy of the satellite. However, the use of GCPs for high-frequency calibration is difficult, and it is particularly difficult to acquire accurate GCPs for the image of a nightlight satellite. In this study, we developed a camera-star sensor installation calibration method that eliminates the need for GCPs. In the proposed method, the camera and star sensor lenses are simultaneously pointed at the star, and the camera-star sensor installation is accurately calibrated by processing the star map obtained by the camera and star sensors. Reference data such as road network and Moon position data were used to verify the proposed method and evaluate its positioning accuracy. The results of the application of the method to the positioning of the Luojia 1-01 satellite indicated an accuracy within 800 m, which is comparable with that of the traditional method.

Download Full-text

Mobile Novelty Mining

International Journal of Advanced Pervasive and Ubiquitous Computing ◽

10.4018/japuc.2009100104 ◽

2009 ◽

Vol 1 (4) ◽

pp. 43-68 ◽

Cited By ~ 12

Author(s):

Agus T. Kwee ◽

Flora S. Tsai

Keyword(s):

Mobile Phones ◽

Web Applications ◽

Relevant Information ◽

The Internet ◽

Use Case ◽

The Novel ◽

Mining System ◽

Service Oriented ◽

Remote System ◽

Client Side

Service-oriented Web applications allow users to exploit applications over networks and access them from a remote system at the client side, including mobile phones. Individual services are built separately with comprehensive functionalities. In this article, the authors transform a standalone offline novelty mining application into a service-oriented application and allow users to access it over the Internet. A novelty mining application mines the novel, yet relevant, information on a topic specified by users. In this article, the authors propose a design for a service-oriented novelty mining application. After deploying their service-oriented novelty mining system on a server, use case scenarios are provided to demonstrate the system. The authors’ service-oriented novelty mining system increases the efficiency of gathering novel information from incoming streams of texts on their mobile devices for users.

Download Full-text

Development of a Novel Gear Measuring Device of High Accuracy

Volume 4: 9th International Power Transmission and Gearing Conference, Parts A and B ◽

10.1115/detc2003/ptg-48105 ◽

2003 ◽

Cited By ~ 5

Author(s):

Frank Ha¨rtig ◽

Christian Keck ◽

Karin Kniel ◽

Heinrich Schwenke ◽

Klaus Wendt ◽

...

Keyword(s):

Manufacturing Industry ◽

Coordinate Measuring Machine ◽

Calibration Method ◽

National Metrology Institute ◽

Distance Information ◽

Measuring Device ◽

Measurement Results ◽

Gear Manufacturing ◽

Measuring Machine ◽

Tracking Interferometer

The German national metrology institute, the Physikalisch-Technische Bundesanstalt (PTB), has developed a novel calibration method for gear artefacts. This reduces the current calibration uncertainty of gear standards, which is an essential step towards meeting the rising quality demands of the gear manufacturing industry. The measurement setup is based on a coordinate measuring machine (CMM) equipped with a high-precision rotary table. The key element of the novel gear measuring device is a tracking interferometer (TI) for reading the distance information. This information is combined with the reading of the coordinate measuring machine line scales in order to reduce the overall measurement uncertainty. If an optimized measurement strategy is applied, the measurement results are almost achieved with laser interferometer accuracy. First simulations and measurement results for an involute profile artefact are presented and discussed.

Download Full-text

Information services for novelty mining

The Knowledge Engineering Review ◽

10.1017/s026988891400006x ◽

2014 ◽

Vol 29 (2) ◽

pp. 234-247

Author(s):

Flora S. Tsai ◽

Agus T. Kwee

Keyword(s):

Information Overload ◽

Relevant Information ◽

Information Services ◽

Test Cases ◽

The Novel ◽

Design And Development ◽

Real World Applications ◽

Remote System ◽

Client Side ◽

Mobile Information Services

AbstractInformation services facilitate users to exploit applications over the network and access them from the remote system at the client side. In this paper, we describe the design and development of information services for novelty mining, which allows users to access the novel yet relevant information of a given topic. Several methodologies regarding novelty mining such as novelty scoring, novelty threshold, novelty feedback, and document-to-sentence technique are described. In addition to Web services, mobile information services are also described. Modelling and implementing information services for novelty mining are especially useful for users to reduce their information overload. We describe the challenging issue of decomposing the complex novelty mining application into several smaller and simpler modules, which are later implemented as services on the Web as well as mobile devices. After deploying our information services for novelty mining, test cases are provided to demonstrate the system. Our information services for novelty mining are confirmed to be helpful in increasing the efficiency of enterprise users in gathering novel information from incoming text. By studying the design and development of information services for novelty mining, we can benefit other developers in investigating effective techniques for developing enterprise services for other real-world applications.

Download Full-text