Using ICESat-2 photon data for estimating lake bathymetry
(2025) In Student thesis series INES NGEM01 20251Dept of Physical Geography and Ecosystem Science
- Abstract
- Bathymetry, the measurement of underwater terrain, is crucial for understanding lake storage volumes, water resource availability, and ecological conditions. While there are an estimated 117 million lakes worldwide, bathymetric data remains limited for most of them. Traditional methods for measuring bathymetry requires fieldwork which is costly and time-consuming. For this reason, new less fieldwork-intensive methods are required.
Satellite remote sensing offers an alternative approach, with recent advancements such as ICESat-2 opening new possibilities for bathymetry estimation. ICESat-2, launched by NASA in 2018, carries a green-wavelength photon-counting laser altimeter capable of penetrating clear water. Unlike traditional optical... (More) - Bathymetry, the measurement of underwater terrain, is crucial for understanding lake storage volumes, water resource availability, and ecological conditions. While there are an estimated 117 million lakes worldwide, bathymetric data remains limited for most of them. Traditional methods for measuring bathymetry requires fieldwork which is costly and time-consuming. For this reason, new less fieldwork-intensive methods are required.
Satellite remote sensing offers an alternative approach, with recent advancements such as ICESat-2 opening new possibilities for bathymetry estimation. ICESat-2, launched by NASA in 2018, carries a green-wavelength photon-counting laser altimeter capable of penetrating clear water. Unlike traditional optical remote sensing methods, which require in situ reference data, ICESat-2’s photon data can potentially be used independently for bathymetric estimation. However, most previous studies have focused on clear, tropic oceanic waters, with limited research exploring how water quality parameters affect ICESat-2’s performance in lakes.
This study aims to address that gap by using ICESat-2 photon data to estimate bathymetry in two lakes: Lake Pyhäjärvi in Finland and Lake Balaton in Hungary and examining which water quality metrics influence the success of these estimations. Bathymetry was estimated using a minimum peak method, and water quality was assessed using chlorophyll, cyanobacteria, turbidity, dissolved organic carbon (DOC), colored dissolved organic matter (CDOM), and water color indices.
The results show that DOC, CDOM, and color had a greater impact on bathymetry estimation success than chlorophyll, turbidity, or cyanobacteria. While Lake Balaton had lower DOC and CDOM levels, it produced usable bathymetric data, Lake Pyhäjärvi, which had higher concentrations of these optical-interfering substances, did not, even though it showed lesser values for cyanobacteria, turbidity and chlorophyll a. For Lake Balaton, the overall accuracy of the estimated bathymetry was approximately 0.9 meters RMSE and MAE, although accuracy varied across different satellite tracks.
The study also found that visually inspecting along-track plots prior to processing can significantly improve accuracy by excluding low-quality data. Further improvements could be achieved by adapting processing parameters (e.g., DBSCAN noise filtering and peak detection thresholds) based on individual track characteristics. (Less) - Popular Abstract
- Bathymetry, the measurement of underwater terrain, is crucial for understanding lake storage volumes, water resource availability, and ecological conditions. While there are an estimated 117 million lakes worldwide, bathymetric data remains limited for most of them. Traditional methods for measuring bathymetry requires fieldwork which is costly and time-consuming. For this reason, new less fieldwork-intensive methods are required.
Satellite remote sensing offers a promising low-cost alternative to traditional methods such as sonar. Both optical and laser ranging based methods have been used successfully in the past. In 2018 NASA launched a satellite, ICESat-2 which carries a laser capable of penetrating the water column and measuring... (More) - Bathymetry, the measurement of underwater terrain, is crucial for understanding lake storage volumes, water resource availability, and ecological conditions. While there are an estimated 117 million lakes worldwide, bathymetric data remains limited for most of them. Traditional methods for measuring bathymetry requires fieldwork which is costly and time-consuming. For this reason, new less fieldwork-intensive methods are required.
Satellite remote sensing offers a promising low-cost alternative to traditional methods such as sonar. Both optical and laser ranging based methods have been used successfully in the past. In 2018 NASA launched a satellite, ICESat-2 which carries a laser capable of penetrating the water column and measuring water depth accurately. Unlike optical remote sensing methods for bathymetry, ICESat-2 derived bathymetry does not need any on site data.
This study aims to measure bathymetry in two lakes- Balaton in Hungary and Pyhäjärvi in Finland. In addition it aims to see if there is any difference between using ICESat-2 for bathymetry in two completely different lakes and if there is, what are the causes for such differences.
The results show that bathymetry could be estimated for lake Balaton but not for Pyhäjärvi. The study concluded that the reason for this is in the optical properties of the water of the lakes. While Balaton is much greener and lighter than Pyhäjärvi its bathymetry can be estimated. As for the bathymetry results themselves the results were mediocre. The average mean error was around 0.9 meters. However all the tracks that met the conditions raised by this study were used for the calculations and no manual selection process was applied. This study concluded that by visually inspecting bathymetric profile graphs before large scale processing the accuracy of the results can be improved significantly. Further improvements could also be achieved by improving the data cleaning process and by manually segmenting the to-be processed bathymetric profiles. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9211370
- author
- Jürimaa, Karl Joann LU
- supervisor
-
- Zheng Duan LU
- organization
- course
- NGEM01 20251
- year
- 2025
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Geography, Physical Geography, Hydrology, Bathymetry, GIS, ICESat-2
- publication/series
- Student thesis series INES
- report number
- 744
- language
- English
- id
- 9211370
- date added to LUP
- 2025-09-01 18:07:41
- date last changed
- 2025-09-01 18:07:41
@misc{9211370,
abstract = {{Bathymetry, the measurement of underwater terrain, is crucial for understanding lake storage volumes, water resource availability, and ecological conditions. While there are an estimated 117 million lakes worldwide, bathymetric data remains limited for most of them. Traditional methods for measuring bathymetry requires fieldwork which is costly and time-consuming. For this reason, new less fieldwork-intensive methods are required.
Satellite remote sensing offers an alternative approach, with recent advancements such as ICESat-2 opening new possibilities for bathymetry estimation. ICESat-2, launched by NASA in 2018, carries a green-wavelength photon-counting laser altimeter capable of penetrating clear water. Unlike traditional optical remote sensing methods, which require in situ reference data, ICESat-2’s photon data can potentially be used independently for bathymetric estimation. However, most previous studies have focused on clear, tropic oceanic waters, with limited research exploring how water quality parameters affect ICESat-2’s performance in lakes.
This study aims to address that gap by using ICESat-2 photon data to estimate bathymetry in two lakes: Lake Pyhäjärvi in Finland and Lake Balaton in Hungary and examining which water quality metrics influence the success of these estimations. Bathymetry was estimated using a minimum peak method, and water quality was assessed using chlorophyll, cyanobacteria, turbidity, dissolved organic carbon (DOC), colored dissolved organic matter (CDOM), and water color indices.
The results show that DOC, CDOM, and color had a greater impact on bathymetry estimation success than chlorophyll, turbidity, or cyanobacteria. While Lake Balaton had lower DOC and CDOM levels, it produced usable bathymetric data, Lake Pyhäjärvi, which had higher concentrations of these optical-interfering substances, did not, even though it showed lesser values for cyanobacteria, turbidity and chlorophyll a. For Lake Balaton, the overall accuracy of the estimated bathymetry was approximately 0.9 meters RMSE and MAE, although accuracy varied across different satellite tracks.
The study also found that visually inspecting along-track plots prior to processing can significantly improve accuracy by excluding low-quality data. Further improvements could be achieved by adapting processing parameters (e.g., DBSCAN noise filtering and peak detection thresholds) based on individual track characteristics.}},
author = {{Jürimaa, Karl Joann}},
language = {{eng}},
note = {{Student Paper}},
series = {{Student thesis series INES}},
title = {{Using ICESat-2 photon data for estimating lake bathymetry}},
year = {{2025}},
}