The Analysis on the Annual Change of Digital Aerial Camera's IMUs Boresight Misalignment

2021 ◽  
Vol 87 (11) ◽  
pp. 801-806
Author(s):  
Abdullah Kayı ◽  
Bülent Bayram ◽  
Dursun Zafer Şeker
Keyword(s):  
Inertial Measurement Unit ◽  
Measurement Unit ◽  
Navigation Systems ◽  
Annual Change ◽  
Short Term ◽  
Inertial Measurement ◽  
Term Stability ◽  
Long Term Stability ◽  
Flight Season

The system calibration determines the position and orientation between the sensor and the navigation systems, such as boresight misalignment. Although there is much research about boresight calibration, there are not sufficient studies on the frequency of the calibration performance. The short-term stability of boresight misalignment was investigated in previous studies, but long-term stability research could not be done. It is important to emphasize that long-term stability is still open to questions. In this study, an Ultracam Eagle digital aerial camera's data from 2012 to 2016 were analyzed and the question of how often calibration should be performed was investigated. Boresight misalignment does not remain constant on a yearly basis and should be calibrated every year before the flight season. It was observed that the boresight misalignment changed dramatically when the inertial measurement unit or camera was removed from the aircraft and sent to the manufacturer for factory calibration.

scholarly journals Scalar Method of Fault Diagnosis of Inertial Measurement Unit

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Vadym Avrutov
Keyword(s):  
Fault Diagnosis ◽  
Inertial Measurement Unit ◽  
Calibration Method ◽  
Quality Monitoring ◽  
Measurement Unit ◽  
Navigation Systems ◽  
Working Capacity ◽  
Element Determination ◽  
Inertial Measurement ◽  
Algorithm Verification

The scalar method of fault diagnosis systems of the inertial measurement unit (IMU) is described. All inertial navigation systems consist of such IMU. The scalar calibration method is a base of the scalar method for quality monitoring and diagnostics. In accordance with scalar calibration method algorithms of fault diagnosis systems are developed. As a result of quality monitoring algorithm verification is implemented in the working capacity monitoring of IMU. A failure element determination is based on diagnostics algorithm verification and after that the reason for such failure is cleared. The process of verifications consists of comparison of the calculated estimations of biases, scale factor errors, and misalignments angles of sensors to their data sheet certificate, kept in internal memory of computer. As a result of such comparison the conclusion for working capacity of each IMU sensor can be made and also the failure sensor can be determined.

scholarly journals A survey of short-term and long-term stability of tube parameters in a mammography unit

2014 ◽  
Vol 29 (4) ◽  
pp. 321-325
Author(s):  
Jovica Praskalo ◽  
Jasna Davidovic ◽  
Biljana Kocic ◽  
Monika Zivkovic ◽  
Svetlana Pejovic
Keyword(s):  
Screening Program ◽  
Short Term ◽  
X Ray ◽  
Term Stability ◽  
Long Term Stability ◽  
Mammography Screening Program ◽  
The Republic ◽  
Set Up ◽  
The Given

In order to set up a successful mammography screening program in the Republic of Srpska, a Siemens Mammomat 1000 X-ray machine was selected for analysis as the said mammography system is widely used in clinical practice. The variations in tube parameters (specific air kerma, high-voltage accuracy and reproducibility, linearity between exposure and dose exposure time) were monitored over a five-year period, from 2008 to 2012. In addition, due to observed daily fluctuations for chosen parameters, a series of measurements were performed three times a day within a single-month period (mainly October 2012). The goal of such an experimental set up is to assess short-term and long-term stability of tube parameters in the given mammography unit and to make a comparison between them. The present paper shows how an early detection of significant parameter fluctuations can help eliminate irregularities and optimize the performance of mammography systems.

scholarly journals Research on the solidification of silt with cement and zeolite as additives

2016 ◽  
Vol 1 (1) ◽  
pp. 35
Author(s):  
Feng Cheng ◽  
Wang Baotian ◽  
Li Shoude
Keyword(s):  
Heavy Metal ◽  
Industrial Pollution ◽  
Unconfined Compressive Strength ◽  
Effective Solution ◽  
Short Term ◽  
Time Saving ◽  
Term Stability ◽  
Long Term Stability ◽  
Environment Problem

Silt solidification is an important method of silt disposal,and it’s proved to be quick effectiveness and time saving and large in capacity.In recent years,the industrial pollution has made the silt in the lake or the sea rich in harmful elements,such as heavy metal and organic matter,etc,which may strongly influence the solidification effect of silt and trigger secondary pollution.The author proposed a kind of choice,which could effectly decrease harmful elements leaching,based on engineering application.The performances of solidification with different ratio of cement and zeolite,such as unconfined compressive strength,compression coefficient,heavy metal fractions,heavy metal short-term stability and long-term stability are systematicly studied.The article confirmed that the addition of the cement and the zeolite increase the strength of the soil and effectly enhance its deformation resistant capability,Further more,they significantly decrease the activity of harmful elements and greatly reduce the threat to the environment,which finds an effective solution to the environment problem.

Fabrication of Boron Compensated Hydrogenated Amorphous Silicon Films with Significantly Improved Stability Using Plasma Enhanced Chemical Vapor Deposition Technique

1995 ◽  
Vol 377 ◽  
Author(s):  
Mohan K. Bhan
Keyword(s):  
Chemical Vapor ◽  
Short Term ◽  
Term Stability ◽  
Long Term Stability ◽  
Vapor Deposition Technique ◽  
Improved Stability ◽  
Donor Acceptor ◽  
B Doping ◽  
The Stability

ABSTRACTWe have systematically investigated the effects of addition of sub-ppm levels of boron on the stability of a-Si:H films and p-i-n devices, deposited by PE-CVD technique. The films thus produced with appropriate amounts of boron, show a significant improvement in stability, when soaked under both AM 1.5 (short-term) as well as 10×sun (long-term) illumination conditions. The opto-electronic properties of the films are quite respectable It is concluded that boron compensates the native impurities by forming donor-acceptor pairs, which reduces the “fast” defects and hence the initial degradation of the films. It is also speculated that boron may also be improving the short-term stability, by reducing the recombination of light generated electrons and holes, by converting D° into D+ states. The long-term stability appears to get affected by hydrogen dilution which seems to reduce the amount of “slow” defects. As a result of B doping of i-layer, the initial conversion efficiency of the devices decreases. It is presumed that our devices may contain an enhanced level of boron impurity, than expected, making them as worse material and to degrade less.

scholarly journals Weather fluctuations drive short‐term dynamics and long‐term stability in plant communities: A 25‐year study in a Central European dry grassland

2020 ◽  
Vol 31 (5) ◽  
pp. 711-721 ◽  
Author(s):  
Felícia M. Fischer ◽  
Kryštof Chytrý ◽  
Jakub Těšitel ◽  
Jiří Danihelka ◽  
Milan Chytrý
Keyword(s):  
Plant Communities ◽  
Short Term ◽  
Dry Grassland ◽  
Central European ◽  
Term Stability ◽  
Long Term Stability

scholarly journals A Waist-Worn Inertial Measurement Unit for Long-Term Monitoring of Parkinson’s Disease Patients

Sensors ◽  
2017 ◽  
Vol 17 (4) ◽  
pp. 827 ◽  
Author(s):  
Daniel Rodríguez-Martín ◽  
Carlos Pérez-López ◽  
Albert Samà ◽  
Andreu Català ◽  
Joan Moreno Arostegui ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Inertial Measurement Unit ◽  
Measurement Unit ◽  
Inertial Measurement ◽  
Long Term Monitoring ◽  
Term Monitoring

Results of experimental tests for the evaluation of the signal-to-noise ratio, short-term stability, linearity in the time axis, and long-term stability of the GPR signal - according to COST Action TU1208 guidelines

2020 ◽  
Author(s):  
Milan Vrtunski ◽  
Lara Pajewski ◽  
Aleksandar Ristić ◽  
Željko Bugarinović ◽  
Miro Govedarica
Keyword(s):  
Ground Penetrating Radar ◽  
Signal To Noise Ratio ◽  
Experimental Tests ◽  
Time Axis ◽  
Short Term ◽  
Cost Action ◽  
Term Stability ◽  
Long Term Stability ◽  
Ground Penetrating

<p>Ground Penetrating Radar (GPR) systems need to be calibrated on a recurrent basis and their performance shall be periodically verified, in accordance with manufacturer recommendations and specifications. Nevertheless, most GPR owners in Europe employ their radar units and antennas for years without ever having them verified by manufacturers, unless major flaws or issues become evident. In this framework, Members of COST Action TU1208 have recently carried out a critical analysis of the few existing procedures for the calibration and performance verification of GPR systems; and, they have proposed four improved experimental tests to evaluate the signal-to-noise ratio, short-term stability, linearity in the time axis, and long-term stability of the GPR signal [1]. In this work, we present the results of the tests executed in Novi Sad, Serbia, on a GSSI SIR 3000 control unit equipped with GSSI ground-coupled antennas having central frequencies of 400 MHz and 900 MHz. We have experienced that the execution of the tests helps to attain stronger awareness about the behaviour and limits of owned GPR equipment. It is also interesting to check how the results of the tests change over time and in different environmental conditions, to analyze the performance evolution of the equipment. Main aim of this abstract is to spread the voice and encourage GPR owners and manufacturers to execute the tests. If a wide variety of control units and antennas are tested, of older and more recent conception, with different numbers of working hours, reliable thresholds for the tests can be established and the proposed procedures can be further refined and upgraded. Moreover, the results of the tests can be translated into accuracy levels of measured physical and geometrical quantities, to get some awareness about the uncertainty of results of a GPR survey (e.g., achieved accuracy levels in the estimation of layer thicknesses).</p><p> </p><p>[1] L. Pajewski, M. Vrtunski, Ž. Bugarinović, A. Ristić, M. Govedarica, A. van der Wielen, C. Grégoire, C. Van Geem, X. Dérobert, V. Borecky, S. Serkan Artagan, S. Fontul, V. Marecos, and S. Lambot, "GPR system performance compliance according to COST Action TU1208 guidelines,"  Ground Penetrating Radar, Volume 1, Issue 2, Article ID GPR-1-2-1, July 2018, pp. 2-36, doi.org/10.26376/GPR2018007.</p>

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