scholarly journals Recent Progress on Vegetation Remote Sensing Using Spaceborne GNSS-Reflectometry

2021 ◽  
Vol 13 (21) ◽  
pp. 4244
Author(s):  
Xuerui Wu ◽  
Peng Guo ◽  
Yueqiang Sun ◽  
Hong Liang ◽  
Xinggang Zhang ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Content ◽  
Global Navigation Satellite System ◽  
Satellite System ◽  
Weak Links ◽  
Navigation Satellite ◽  
Exploratory Research ◽  
Vegetation Monitoring ◽  
Global Navigation ◽  
Global Navigation Satellite

Vegetation is an important part of the terrestrial ecosystem and plays a vital role in the global carbon cycle. Traditional remote sensing methods have certain limitations in vegetation monitoring, and the development of GNSS-R (Global Navigation Satellite System-Reflectometry) technology provides a new and complimentary method. With the CYGNSS (Cyclone Global Navigation Satellite System) launch and the increased data acquisition, the use of spaceborne GNSS-R for vegetation monitoring has become a research hotspot. However, due to the complex characteristics of vegetation, its application in this field is still in the exploratory research stage. On the basis of reviewing the current research status, this paper points out the weak links of this technology in terms of polarization and observation geometry. Combined with the microwave vegetation scattering model, this paper analyzes the full polarization bistatic scattering characteristics of vegetation and points out the influence of vegetation parameters (density, water content, and vegetation diameters). The potential feasibility of polarization GNSS-R and future development trends of GNSS-R technology in quantitative retrieval (such as vegetation water content and biomass) are also discussed.

scholarly journals Legal Review of the Liability Framework for Remote Sensing by Looking at the Global Navigation Satellite System (GNSS)

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Simin Asadzadeh Talei ◽  
Sepideh Bouzari ◽  
Sakineh Bagheri
Keyword(s):  
Remote Sensing ◽  
Global Navigation Satellite System ◽  
Civil Liability ◽  
Satellite System ◽  
Navigation Satellite ◽  
Legal Recognition ◽  
The Subject ◽  
Global Navigation ◽  
The Law ◽  
Global Navigation Satellite

Compensation for losses in the law is certain and the civil liability system is designed to respond to this need. Nowadays, it is necessary to check compensation in different fields, and specialists in each field are seeking data to recognize liability issues and even reduce the risk of liability in their work. The legal recognition of the subject is necessary because the field of remote sensing and mapping is one of the fields with many activists and plays an important role in various aspects of the life of the community, but many people still do not have any data about their rights, and even those involved in this field as producers or consumers does not have legal data on this issue, and due to the involvement of this data in the lives of individuals and the existence of relevant cases in the judiciary. Therefore, the accurate recognition of this issue will cause questions in this field to be answered in law. And lawyers and judges can also rely on the recognition and analysis of this issue to avoid error and work more efficiently.Key words: Liability, Remote Sensing, Fault, Global Navigation Satellite System (GNSS)

scholarly journals Evaluation of CYGNSS Observations for Flood Detection and Mapping during Sistan and Baluchestan Torrential Rain in 2020

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2047
Author(s):  
Mahmoud Rajabi ◽  
Hossein Nahavandchi ◽  
Mostafa Hoseini
Keyword(s):  
Remote Sensing ◽  
Global Navigation Satellite System ◽  
Satellite System ◽  
Navigation Satellite ◽  
Management Options ◽  
Torrential Rain ◽  
Global Navigation ◽  
Flood Detection ◽  
Global Navigation Satellite ◽  
Sistan And Baluchestan

Flood detection and produced maps play essential roles in policymaking, planning, and implementing flood management options. Remote sensing is commonly accepted as a maximum cost-effective technology to obtain detailed information over large areas of lands and oceans. We used remote sensing observations from Global Navigation Satellite System-Reflectometry (GNSS-R) to study the potential of this technique for the retrieval of flood maps over the regions affected by the recent flood in the southeastern part of Iran. The evaluation was made using spaceborne GNSS-R measurements over the Sistan and Baluchestan provinces during torrential rain in January 2020. This area has been at a high risk of flood in recent years and needs to be continuously monitored by means of timely observations. The main dataset was acquired from the level-1 data product of the Cyclone Global Navigation Satellite System (CYGNSS) spaceborne mission. The mission consisted of a constellation of eight microsatellites with GNSS-R sensors onboard to receive forward-scattered GNSS signals from the ocean and land. We first focused on data preparation and eliminating the outliers. Afterward, the reflectivity of the surface was calculated using the bistatic radar equations formula. The flooded areas were then detected based on the analysis of the derived reflectivity. Images from Moderate-Resolution Imaging Spectroradiometer (MODIS) were used for evaluation of the results. The analysis estimated the inundated area of approximately 19,644 km2 (including Jaz-Murian depression) to be affected by the flood in the south and middle parts of the Sistan and Baluchestan province. Although the main mission of CYGNSS was to measure the ocean wind speed in hurricanes and tropical cyclones, we showed the capability of detecting floods in the study area. The sensitivity of the spaceborne GNSS-R observations, together with the relatively short revisit time, highlight the potential of this technique to be used in flood detection. Future GNSS-R missions capable of collecting the reflected signals from all available multi-GNSS constellations would offer even more detailed information from the flood-affected areas.

scholarly journals OutFin, a multi-device and multi-modal dataset for outdoor localization based on the fingerprinting approach

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Fahad Alhomayani ◽  
Mohammad H. Mahoor
Keyword(s):  
Global Navigation Satellite System ◽  
Urban Areas ◽  
Satellite System ◽  
Reference Points ◽  
Navigation Satellite ◽  
Data Types ◽  
Entry Barrier ◽  
Promising Alternative ◽  
Global Navigation ◽  
Global Navigation Satellite

AbstractIn recent years, fingerprint-based positioning has gained researchers’ attention since it is a promising alternative to the Global Navigation Satellite System and cellular network-based localization in urban areas. Despite this, the lack of publicly available datasets that researchers can use to develop, evaluate, and compare fingerprint-based positioning solutions constitutes a high entry barrier for studies. As an effort to overcome this barrier and foster new research efforts, this paper presents OutFin, a novel dataset of outdoor location fingerprints that were collected using two different smartphones. OutFin is comprised of diverse data types such as WiFi, Bluetooth, and cellular signal strengths, in addition to measurements from various sensors including the magnetometer, accelerometer, gyroscope, barometer, and ambient light sensor. The collection area spanned four dispersed sites with a total of 122 reference points. Each site is different in terms of its visibility to the Global Navigation Satellite System and reference points’ number, arrangement, and spacing. Before OutFin was made available to the public, several experiments were conducted to validate its technical quality.

Implementation of a Dual-Frequency GLONASS and GPS L1 C/A Software Receiver

2010 ◽  
Vol 63 (2) ◽  
pp. 269-287 ◽  
Author(s):  
S. Abbasian Nik ◽  
M. G. Petovello
Keyword(s):  
Global Navigation Satellite System ◽  
Critical Role ◽  
Satellite System ◽  
Navigation Satellite ◽  
Dual Frequency ◽  
Software Receiver ◽  
The Public ◽  
Global Navigation ◽  
Global Navigation Satellite

These days, Global Navigation Satellite System (GNSS) technology plays a critical role in positioning and navigation applications. Use of GNSS is becoming more of a need to the public. Therefore, much effort is needed to make the civilian part of the system more accurate, reliable and available, especially for the safety-of-life purposes. With the recent revitalization of Russian Global Navigation Satellite System (GLONASS), with a constellation of 20 satellites in August 2009 and the promise of 24 satellites by 2010, it is worthwhile concentrating on the GLONASS system as a method of GPS augmentation to achieve more reliable and accurate navigation solutions.

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