• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.3-6
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• 2007

The GPS baseline processing and the network adjustment was required a preliminary classification and check for effective work because the observation data of GPS $3^{rd}$ order control points are enormous attain to about 12,000 points. Particularly, in baseline processing and network adjustment a inaccuracy GPS antenna heights and point names yield a gross error or a S/W computation error. For the baseline processing of observation data, the related all materials were collected and were required a final check. The factor occurring a error, in GPS the baseline processing, were inspected variously after a checking observation data. Also, baseline processing method of GPS $3^{rd}$ order control points were commented and the analysis carry out a results with a experiment. The ellipsoidal distance and height of duplication baseline was compared between adjoin campaign areas for a accuracy analysis of baseline processing. According to the result, the mean is about 1cm for horizontal direction and about 2cm for vertical direction.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.2
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• pp.103-111
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• 2021

A series of experiments have been carried out by using National Geographic Information Institute(NGII)'s Continuously Operating Reference Station (CORS) data with various strategies to analyze the impact of multi-GNSS measurements on baseline processing. The results of baseline processing were compared in terms of ambiguity fixing rate, precision, and hypothesis tests were conducted to confirm the statistical difference. The combination of multi-GNSS measurements has helped to improve ambiguity fixing rate, especially under harsh positioning environments. Combination of GPS, Galileo, BeiDou could get better precision than that of GPS, GLONASS, Galileo, and adding QZSS made the baseline solution's vertical component more precisely. The hypothesis tests have statistically confirmed that the inclusion of the multi-GNSS in the baseline processing enables not only to reduce field observation time length but also to enhance the solution's precision. However, it is of interest to notice that results of the baseline solution are dependent upon the software used. Hence, comprehensive studies should be performed shortly to derive the best practice to select the appropriate software.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1287-1294
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• 2001

As size of waveform is very small, ECG(electrocardiogram) signal is difficult to analyze for noise which is occurred when it measures. In order to obtain ECG clearly, it must eliminate that power line interference, baseline wandering, noise of muscle constriction. In ECG, the worst problem which is recorded signal of ECG is the baseline wandering elimination, which is occurred by rhythm of respiration and muscle constriction of part from attaching to an electrode. Such the baseline is roughly irregular wandering and shaking up and down therefore the part of the baseline wandering elimination is very important because it is difficulty of ECG diagnosis. In this study, as implementation of real-time signal processing digital filter it is applicable to analyze patient's heart disease by way of design of the baseline wandering elimination system.

• The KIPS Transactions:PartA
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• v.18A no.3
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• pp.99-108
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• 2011

Processor technology is currently continued to parallel processing techniques, not by only increasing clock frequency of a single processor due to the high technology cost and power consumption. In this paper, a SIMD (Single Instruction Multiple Data) based parallel processor is introduced that efficiently processes massive data inherent in multimedia. In addition, this paper proposes pixel subword parallel processing instructions for the SIMD parallel processor architecture that efficiently operate on the image and video pixels. The proposed pixel subword parallel processing instructions store and process four 8-bit pixels on the partitioned four 12-bit registers in a 48-bit datapath architecture. This solves the overflow problem inherent in existing multimedia extensions and reduces the use of many packing/unpacking instructions. Experimental results using the same SIMD-based parallel processor architecture indicate that the proposed pixel subword parallel processing instructions achieve a speedup of $2.3{\times}$ over the baseline SIMD array performance. This is in contrast to MMX-type instructions (a representative Intel multimedia extension), which achieve a speedup of only $1.4{\times}$ over the same baseline SIMD array performance. In addition, the proposed instructions achieve $2.5{\times}$ better energy efficiency than the baseline program, while MMX-type instructions achieve only $1.8{\times}$ better energy efficiency than the baseline program.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.5
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• pp.421-427
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• 2013

In general, it can be assumed that the tropospheric effect are removed through double-differencing technique in short-baseline GPS data processing. This means that the high-accuracy positioning can be obtained because various error sources can be eliminated and the number of unknown can be decreased in the adjustment computation procedure. As a consequence, short-baseline data processing is widely used in the fields such as deformation monitoring which require precise positioning. However, short-baseline data processing is limited to achieve high positioning accuracy when the height difference between the reference and the rover station is significant. In this study, the effects of tropospheric delays on the determination of short-baseline is analyzed, which depends on the orientation of baseline. The GPS measurements which include tropospheric effect and measurement noises are generated by simulation, and then rover coordinates are computed by short-baseline data processing technique. The residuals of rover coordinates are analyzed to interpret the tropospheric effect on the positioning. The results show that the magnitudes of the biases in the coordinate residuals increase as the baseline length gets longer. The increasing rate is computed as 0.07cm per meter in baseline length. Therefore, the tropospheric effects should be carefully considered in short-baseline data processing when the significant height difference between the reference and rover is observed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.2
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• pp.123-129
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• 2003

This study analyzed and compared the results of baseline processing by Bernese GPS software packages and by GPSurvey software respectively. Then it investigated considerations when very long baselines are processed. There are rarely differences which is accompanied by baseline length when it is processed by Bernese GPS software but there are somewhat differences in proportion to the baseline length when it is processed by GPSurvey software.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.4
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• pp.245-254
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• 2018

Impact of tropospheric correction techniques on accuracy of the GPS (Global Positioning System) derived ellipsoidal heights has been experimentally assessed in this paper. To this end, 247 baselines were constructed from a total of 88 CORS (Continuously Operating Reference Stations) in Korea. The GPS measurements for seven days, acquired from the so-called integrated GNSS (Global Navigation Satellite Systems) data center via internet connection, have been processed by two baseline processing software packages with an application of the empirical models, such as Hopfield, modified Hopfield and Saastamoinen, and the estimation techniques based on the DD (Double-Differenced) measurements and the PPP (Precise Point Positioning) technique; hence a total number of the baseline processed and tested was 8,645. Accuracy and precision of the estimated heights from the various correction schemes were analyzed about baseline lengths and height differences of the testing baselines. Details of these results are summarized with a view to hopefully providing an overall guideline of a suitable selection of the modeling scheme with respect to processing conditions, such as the baseline length and the height differences.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.181-182
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• 2010

For real-time displacement monitoring of large-scale structures, the high-rate (>1 Hz) GPS data processing is necessary, which is not possible even for the scientific GPS data processing softwares. Since the baseline is generally very short in this case, most of the atmospheric effects are removed, resulting in the unknowns of position and integer ambiguity. The number of unknowns in real-time kinematic GPS positioning makes the positioning impossible with usual approach, thus two-step approach is tested in this study.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.04a
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• pp.103-118
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• 2002

There are many GPS software packages and this document compared the result of baseline processing by Bernese GPS software with it by GPSurvey software. This paper also analyzed the results and investigated considerations when very long baselines are processed. There are rarely differences which is accompanied by baseline distance when it is processed by Bernese GPS software but there are somewhat differences which is accompanied by baseline distance when it is processed by GPSurvey software.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.2
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• pp.157-164
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• 2008

GPS baseline analysis is a mathematical procedure which estimates a baseline vector from carrier-phase double-differenced observations. Least squares technique is generally applied for the processing and integer ambiguities in the observations should be resolved to obtain maximum accuracy of the solution. In GPS control surveying, after assembling the baseline solutions into a network, adjustment is performed to derive final coordinate sets of unknown points. This paper deals with details of GPS baseline analysis for the $2^{nd}$ order national geodetic network adjustment. After reviewing GPS campaigns carried out by National Geographic Information Institute (NGII) and their observations. technical issues and considerations for the GPS baseline analysis are presented with emphasis of selecting the processing strategies and software. Finally, the analyzed results will be evaluated by examining the close of figures formed by joining the processed baseline vectors.