Estimating Mass Balance of White Glacier using ICESat-2

2021 ◽  
Author(s):  
Rachel Lackey
Keyword(s):  
Mass Balance ◽  
Laser Beams ◽  
Altimeter Data ◽  
Altimetry Data ◽  
Laser Altimeter ◽  
Ice Cloud ◽  
Geodetic Technique ◽  
Travel Restrictions ◽  
The Difference ◽  
Satellite Altimetry Data

White Glacier is located on Axel Heiberg Island in Nunavut, Canada, and has had its mass balance actively monitored since 1960. Due to COVID-19 travel restrictions it not possible for researchers to travel to White Glacier and perform the measurements required. This results in gaps in data required to determine the mass balance for 2018-2020. In this study we aim to collect and process laser altimeter data to be interpolated to calculate an estimate of the Mass Balance of White Glacier. This study will be completed using a geodetic technique that utilizes the Ice Cloud and Elevation-2 (ICESat-2) satellite altimetry data. ICESat-2 is carrying ATLAS which is an Advanced Topographic Laser Altimeter that is equipped with six laser beams divided into three pairs that measure lidar altimetry to derive surface height. The longitude, latitude, datetime, and land ice height values were extracted over the Expedition fjord region using MATLAB. The land ice tracks were brought into ArcGIS for analysis, three repeat tracks in the Expedition Fjord region were selected for analysis to determine the difference in elevation between the premelt seasons of 2019 and 2020 as well as one track comparing the premelt and melt seasons of 2019. These elevation differences will be interpolated as accumulation or ablation dependant on the location on the glacier and used to estimate mass balance.

scholarly journals POINTING ANGLE CALIBRATION OF ZY3-02 SATELLITE LASER ALTIMETER USING TERRAIN MATCHING

2017 ◽  
Vol XLII-1/W1 ◽  
pp. 205-210 ◽  
Author(s):  
G. Li ◽  
X. Tang ◽  
X. Gao ◽  
J. P. Huang ◽  
J. Chen ◽  
...  
Keyword(s):  
Altimetry Data ◽  
Laser Altimetry ◽  
Angle Error ◽  
Laser Altimeter ◽  
Geometric Calibration ◽  
Pointing Error ◽  
The Public ◽  
Ice Cloud ◽  
Laser Data ◽  
Terrain Matching

After GLAS (Geo-science Laser Altimeter System) loaded on the ICESat (Ice Cloud and land Elevation Satellite), satellite laser altimeter attracts more and more attention. ZY3-02 equipped with the Chinese first satellite laser altimeter has been successfully launched on 30<sup>th</sup> May, 2016. The geometric calibration is an important step for the laser data processing and application. The method to calculate the laser pointing angle error based on existed reference terrain data is proposed in this paper. The public version terrain data, such as 90m-SRTM and 30m-AW3D30, can be used to estimate the pointing angle of laser altimeter. The GLAS data with simulated pointing error and actual ZY3-02 laser altimetry data is experimented to validate the algorithm. The conclusion will be useful for the future domestic satellite laser altimeter.

scholarly journals IMPROVE THE ZY-3 HEIGHT ACCURACY USING ICESAT/GLAS LASER ALTIMETER DATA

2016 ◽  
Vol XLI-B1 ◽  
pp. 37-42
Author(s):  
Guoyuan Li ◽  
Xinming Tang ◽  
Xiaoming Gao ◽  
Chongyang Zhang ◽  
Tao Li
Keyword(s):  
High Resolution ◽  
Bundle Adjustment ◽  
Experimental Result ◽  
Altimeter Data ◽  
Surface Model ◽  
Laser Altimetry ◽  
Laser Altimeter ◽  
Ice Cloud ◽  
Elevation Data ◽  
Polar Ice Sheets

ZY-3 is the first civilian high resolution stereo mapping satellite, which has been launched on 9th, Jan, 2012. The aim of ZY-3 satellite is to obtain high resolution stereo images and support the 1:50000 scale national surveying and mapping. Although ZY-3 has very high accuracy for direct geo-locations without GCPs (Ground Control Points), use of some GCPs is still indispensible for high precise stereo mapping. The GLAS (Geo-science Laser Altimetry System) loaded on the ICESat (Ice Cloud and land Elevation Satellite), which is the first laser altimetry satellite for earth observation. GLAS has played an important role in the monitoring of polar ice sheets, the measuring of land topography and vegetation canopy heights after launched in 2003. Although GLAS has ended in 2009, the derived elevation dataset still can be used after selection by some criteria. <br><br> In this paper, the ICESat/GLAS laser altimeter data is used as height reference data to improve the ZY-3 height accuracy. A selection method is proposed to obtain high precision GLAS elevation data. Two strategies to improve the ZY-3 height accuracy are introduced. One is the conventional bundle adjustment based on RFM and bias-compensated model, in which the GLAS footprint data is viewed as height control. The second is to correct the DSM (Digital Surface Model) straightly by simple block adjustment, and the DSM is derived from the ZY-3 stereo imaging after freedom adjustment and dense image matching. The experimental result demonstrates that the height accuracy of ZY-3 without other GCPs can be improved to 3.0 meter after adding GLAS elevation data. What’s more, the comparison of the accuracy and efficiency between the two strategies is implemented for application.

scholarly journals IMPROVE THE ZY-3 HEIGHT ACCURACY USING ICESAT/GLAS LASER ALTIMETER DATA

2016 ◽  
Vol XLI-B1 ◽  
pp. 37-42 ◽  
Author(s):  
Guoyuan Li ◽  
Xinming Tang ◽  
Xiaoming Gao ◽  
Chongyang Zhang ◽  
Tao Li
Keyword(s):  
High Resolution ◽  
Bundle Adjustment ◽  
Experimental Result ◽  
Altimeter Data ◽  
Surface Model ◽  
Laser Altimetry ◽  
Laser Altimeter ◽  
Ice Cloud ◽  
Elevation Data ◽  
Polar Ice Sheets

ZY-3 is the first civilian high resolution stereo mapping satellite, which has been launched on 9th, Jan, 2012. The aim of ZY-3 satellite is to obtain high resolution stereo images and support the 1:50000 scale national surveying and mapping. Although ZY-3 has very high accuracy for direct geo-locations without GCPs (Ground Control Points), use of some GCPs is still indispensible for high precise stereo mapping. The GLAS (Geo-science Laser Altimetry System) loaded on the ICESat (Ice Cloud and land Elevation Satellite), which is the first laser altimetry satellite for earth observation. GLAS has played an important role in the monitoring of polar ice sheets, the measuring of land topography and vegetation canopy heights after launched in 2003. Although GLAS has ended in 2009, the derived elevation dataset still can be used after selection by some criteria. &lt;br&gt;&lt;br&gt; In this paper, the ICESat/GLAS laser altimeter data is used as height reference data to improve the ZY-3 height accuracy. A selection method is proposed to obtain high precision GLAS elevation data. Two strategies to improve the ZY-3 height accuracy are introduced. One is the conventional bundle adjustment based on RFM and bias-compensated model, in which the GLAS footprint data is viewed as height control. The second is to correct the DSM (Digital Surface Model) straightly by simple block adjustment, and the DSM is derived from the ZY-3 stereo imaging after freedom adjustment and dense image matching. The experimental result demonstrates that the height accuracy of ZY-3 without other GCPs can be improved to 3.0 meter after adding GLAS elevation data. What’s more, the comparison of the accuracy and efficiency between the two strategies is implemented for application.

scholarly journals Performance Assessment of ICESat-2 Laser Altimeter Data for Water-Level Measurement over Lakes and Reservoirs in China

2020 ◽  
Vol 12 (5) ◽  
pp. 770 ◽  
Author(s):  
Cui Yuan ◽  
Peng Gong ◽  
Yuqi Bai
Keyword(s):  
Measurement Uncertainty ◽  
Large Scale ◽  
Temporal Frequency ◽  
Altimeter Data ◽  
Profile Measurement ◽  
Accuracy Evaluation ◽  
Radar Altimeter ◽  
Laser Altimeter ◽  
Ice Cloud ◽  
Lakes And Reservoirs

Although the Advanced Topographic Laser Altimeter System (ATLAS) onboard the Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) was primarily designed for glacier and sea-ice measurement, it can also be applied to monitor lake surface height (LSH). However, its performance in monitoring lakes/reservoirs has rarely been assessed. Here, we report an accuracy evaluation of the ICESat-2 laser altimetry data over 30 reservoirs in China using gauge data. To show its characteristics in large-scale lake monitoring, we also applied an advanced radar altimeter SARAL (Satellite for ARgos and ALtika) and the first laser altimeter ICESat (Ice, Cloud and land Elevation Satellite) to investigate all lakes and reservoirs (>10 km2) in China. We found that the ICESat-2 has a greatly improved altimetric capability, and the relative altimetric error was 0.06 m, while the relative altimetric error was 0.25 m for SARAL. Compared with SARAL and ICESat data, ICESat-2 data had the lowest measurement uncertainty (the standard deviation of along-track heights; 0.02 m vs. 0.17 m and 0.07 m), the greatest temporal frequency (3.43 vs. 1.35 and 1.48 times per year), and the second greatest lake coverage (636 vs. 814 and 311 lakes). The precise LSH profiles derived from the ICESat-2 data showed that most lakes (90% of 636 lakes) had a quasi-horizontal LSH profile (measurement uncertainty <0.05 m), and special methods are needed for mountainous lakes or shallow lakes to extract precise LSHs.

scholarly journals Inferred basal friction and surface mass balance of the Northeast Greenland Ice Stream using data assimilation of ICESat (Ice Cloud and land Elevation Satellite) surface altimetry and ISSM (Ice Sheet System Model)

2014 ◽  
Vol 8 (6) ◽  
pp. 2335-2351 ◽  
Author(s):  
E. Larour ◽  
J. Utke ◽  
B. Csatho ◽  
A. Schenk ◽  
H. Seroussi ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Mass Balance ◽  
Ice Sheet ◽  
System Model ◽  
Surface Mass Balance ◽  
Altimetry Data ◽  
Ice Flow ◽  
Surface Mass ◽  
Ice Cloud ◽  
Basal Friction

Abstract. We present a new data assimilation method within the Ice Sheet System Model (ISSM) framework that is capable of assimilating surface altimetry data from missions such as ICESat (Ice Cloud and land Elevation Satellite) into reconstructions of transient ice flow. The new method relies on algorithmic differentiation to compute gradients of objective functions with respect to model forcings. It is applied to the Northeast Greenland Ice Stream, where surface mass balance and basal friction forcings are temporally inverted, resulting in adjusted modeled surface heights that best fit existing altimetry. This new approach allows for a better quantification of basal and surface processes and a better understanding of the physical processes currently missing in transient ice-flow models to better capture the important intra- and interannual variability in surface altimetry. It also demonstrates that large spatial and temporal variability is required in model forcings such as surface mass balance and basal friction, variability that can only be explained by including more complex processes such as snowpack compaction at the surface and basal hydrology at the bottom of the ice sheet. This approach is indeed a first step towards assimilating the wealth of high spatial resolution altimetry data available from EnviSat, ICESat, Operation IceBridge and CryoSat-2, and that which will be available in the near future with the launch of ICESat-2.

scholarly journals CONTRIBUTION OF SATELLITE ALTIMETRY DATA IN GEOLOGICAL STRUCTURE RESEARCH IN THE SOUTH CHINA SEA

2016 ◽  
Vol XLI-B8 ◽  
pp. 1187-1190 ◽  
Author(s):  
Tuan Dung Tran ◽  
Thi Huong Mai Ho
Keyword(s):  
Satellite Altimetry ◽  
Geological Structure ◽  
Altimeter Data ◽  
Altimetry Data ◽  
The South ◽  
Satellite Altimeter ◽  
China Sea ◽  
Geological Features ◽  
Marine Gravity ◽  
Satellite Altimetry Data

The study area is bordered on the East China Sea, the Philippine Sea, and the Australian-Indo plate in the Northeast, in the East and in the South, respectively. It is a large area with the diversely complicated conditions of geological structure. In spite of over the past many years of investigation, marine geological structure in many places have remained poorly understood because of a thick seawater layer as well as of the sensitive conflicts among the countries in the region. &lt;br&gt;&lt;br&gt; In recent years, the satellite altimeter technology allows of enhancement the marine investigation in any area. The ocean surface height is measured by a very accurate radar altimeter mounted on a satellite. Then, that surface can be converted into marine gravity anomaly or bathymetry by using the mathematical model. It is the only way to achieve the data with a uniform resolution in acceptable time and cost. The satellite altimetry data and its variants are essential for understanding marine geological structure. They provide a reliable opportunity to geologists and geophysicists for studying the geological features beneath the ocean floor. Also satellite altimeter data is perfect for planning the more detailed shipboard surveys. Especially, it is more meaningful in the remote or sparsely surveyed regions. &lt;br&gt;&lt;br&gt; In this paper, the authors have effectively used the satellite altimetry and shipboard data in combination. Many geological features, such as seafloor spreading ridges, fault systems, volcanic chains as well as distribution of sedimentary basins are revealed through the 2D, 3D model methods of interpretation of satellite-shipboard-derived data and the others. These results are improved by existing boreholes and seismic data in the study area.

scholarly journals An inventory of active subglacial lakes in Antarctica detected by ICESat (2003–2008)

2009 ◽  
Vol 55 (192) ◽  
pp. 573-595 ◽  
Author(s):  
Benjamin E. Smith ◽  
Helen A. Fricker ◽  
Ian R. Joughin ◽  
Slawek Tulaczyk
Keyword(s):  
Surface Deformation ◽  
Water Movement ◽  
Ice Sheet ◽  
Altimeter Data ◽  
Laser Altimeter ◽  
Ice Cloud ◽  
Hydrologic Systems ◽  
Glacier Flow ◽  
Subglacial Lakes ◽  
Response To Water

AbstractThrough the detection of surface deformation in response to water movement, recent satellite studies have demonstrated the existence of subglacial lakes in Antarctica that fill and drain on timescales of months to years. These studies, however, were confined to specific regions of the ice sheet. Here we present the first comprehensive study of these ‘active’ lakes for the Antarctic ice sheet north of 86° S, based on 4.5 years (2003–08) of NASA’s Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data. Our analysis has detected 124 lakes that were active during this period, and we estimate volume changes for each lake. The ICESat-detected lakes are prevalent in coastal Antarctica, and are present under most of the largest ice-stream catchments. Lakes sometimes appear to transfer water from one to another, but also often exchange water with distributed sources undetectable by ICESat, suggesting that the lakes may provide water to or withdraw water from the hydrologic systems that lubricate glacier flow. Thus, these reservoirs may contribute pulses of water to produce rapid temporal changes in glacier speeds, but also may withdraw water at other times to slow flow.

scholarly journals Improved GRACE regional mass balance estimates of the Greenland ice sheet cross-validated with the input–output method

2016 ◽  
Vol 10 (2) ◽  
pp. 895-912 ◽  
Author(s):  
Zheng Xu ◽  
Ernst J. O. Schrama ◽  
Wouter van der Wal ◽  
Michiel van den Broeke ◽  
Ellyn M. Enderlin
Keyword(s):  
Mass Balance ◽  
Climate Model ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Mass Change ◽  
Input Output ◽  
Surface Mass ◽  
Ice Cloud ◽  
The Difference ◽  
Gravity Recovery

Abstract. In this study, we use satellite gravimetry data from the Gravity Recovery and Climate Experiment (GRACE) to estimate regional mass change of the Greenland ice sheet (GrIS) and neighboring glaciated regions using a least squares inversion approach. We also consider results from the input–output method (IOM). The IOM quantifies the difference between the mass input and output of the GrIS by studying the surface mass balance (SMB) and the ice discharge (D). We use the Regional Atmospheric Climate Model version 2.3 (RACMO2.3) to model the SMB and derive the ice discharge from 12 years of high-precision ice velocity and thickness surveys. We use a simulation model to quantify and correct for GRACE approximation errors in mass change between different subregions of the GrIS, and investigate the reliability of pre-1990s ice discharge estimates, which are based on the modeled runoff. We find that the difference between the IOM and our improved GRACE mass change estimates is reduced in terms of the long-term mass change when using a reference discharge derived from runoff estimates in several subareas. In most regions our GRACE and IOM solutions are consistent with other studies, but differences remain in the northwestern GrIS. We validate the GRACE mass balance in that region by considering several different GIA models and mass change estimates derived from data obtained by the Ice, Cloud and land Elevation Satellite (ICESat). We conclude that the approximated mass balance between GRACE and IOM is consistent in most GrIS regions. The difference in the northwest is likely due to underestimated uncertainties in the IOM solutions.

scholarly journals Iterative Pointing Angle Calibration Method for the Spaceborne Photon-Counting Laser Altimeter Based on Small-Range Terrain Matching

2019 ◽  
Vol 11 (18) ◽  
pp. 2158
Author(s):  
Nan ◽  
Feng ◽  
Liu ◽  
Li
Keyword(s):  
Photon Counting ◽  
Calibration Method ◽  
High Repetition Rate ◽  
Search Method ◽  
Airborne Lidar ◽  
Altimeter Data ◽  
Small Range ◽  
Laser Altimeter ◽  
Ice Cloud ◽  
Terrain Matching

The satellite, Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) has been equipped with a new type of spaceborne laser altimeter, which has the benefits of having small footprints and a high repetition rate, and it can produce dense footprints on the ground. Focusing on the pointing angle calibration of this new spaceborne laser altimeter, this paper proposes a fast pointing angle calibration method using only a small range of terrain surveyed by airborne lidar. Based on the matching criterion of least elevation difference, an iterative pointing angle calibration method was proposed. In the experiment, the simulated photon-counting laser altimeter data and the Ice, Cloud and Land Elevation Satellite-2 data were used to verify the algorithm. The results show that when 1 km and 2.5 km lengths of track were used, the pointing angle error after calibration could be reduced to about 0.3 arc-seconds and less than 0.1 arc-seconds, respectively. Meanwhile, compared with the traditional pyramid search method, the proposed iterative pointing angle calibration method does not require well-designed parameters, which are important in the pyramid search method to balance calculation time and calibration result, and the iterative pointing angle calibration method could significantly reduce the calibration time to only about one-fifth of that of the pyramid search method.

scholarly journals CONTRIBUTION OF SATELLITE ALTIMETRY DATA IN GEOLOGICAL STRUCTURE RESEARCH IN THE SOUTH CHINA SEA

2016 ◽  
Vol XLI-B8 ◽  
pp. 1187-1190
Author(s):  
Tuan Dung Tran ◽  
Thi Huong Mai Ho
Keyword(s):  
Satellite Altimetry ◽  
Geological Structure ◽  
Altimeter Data ◽  
Altimetry Data ◽  
The South ◽  
Satellite Altimeter ◽  
China Sea ◽  
Geological Features ◽  
Marine Gravity ◽  
Satellite Altimetry Data

The study area is bordered on the East China Sea, the Philippine Sea, and the Australian-Indo plate in the Northeast, in the East and in the South, respectively. It is a large area with the diversely complicated conditions of geological structure. In spite of over the past many years of investigation, marine geological structure in many places have remained poorly understood because of a thick seawater layer as well as of the sensitive conflicts among the countries in the region. <br><br> In recent years, the satellite altimeter technology allows of enhancement the marine investigation in any area. The ocean surface height is measured by a very accurate radar altimeter mounted on a satellite. Then, that surface can be converted into marine gravity anomaly or bathymetry by using the mathematical model. It is the only way to achieve the data with a uniform resolution in acceptable time and cost. The satellite altimetry data and its variants are essential for understanding marine geological structure. They provide a reliable opportunity to geologists and geophysicists for studying the geological features beneath the ocean floor. Also satellite altimeter data is perfect for planning the more detailed shipboard surveys. Especially, it is more meaningful in the remote or sparsely surveyed regions. <br><br> In this paper, the authors have effectively used the satellite altimetry and shipboard data in combination. Many geological features, such as seafloor spreading ridges, fault systems, volcanic chains as well as distribution of sedimentary basins are revealed through the 2D, 3D model methods of interpretation of satellite-shipboard-derived data and the others. These results are improved by existing boreholes and seismic data in the study area.

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