Inland Water Bodies Monitoring using Satellite Altimetry over Indian Region

Abstract

ABSTRACT:Satellite altimetry for inland water applications has evolved from investigation of water height retrieval to monitoring since last two decades. Altimetry derived reservoir/ river levels can subsequently be used to deal with key inland water resources problems such as flood, rating curve generation for remote locations, reservoir operations, and calibration of river/lake models. In this work 29 inland water bodies were selected over Indian region to monitor from satellite altimetry. First cut selection of potential water bodies was based on availability of altimeter tracks and geographic locations. Then feasibility study was carried out to check the potential of availability of in-situ measurement and scope of GPS survey for final selection. An algorithm is proposed and tested for the waterlevel retrieval over the Ukai Reservoir which fulfil all the necessary requirements. The methodology is based on averaged high rate waveforms, modified retracker and range corrections. The results were then validated with the GPS survey and in-situ tide gauge dataset. SARAL derived water-level information for six different retrackers were compared with the in-situ tide-gauge dataset installed close to the Ukai Dam. Averaged high rate waveforms were analysed for better performance, i.e. single 40Hz, and multiple 40-Hz. A field trip was conducted on 17 th January 2014, same day on the SARAL pass, using two Dual frequency GPS instruments. New improved retracker work best with overall RMSE within the range of 8 cm. The results supports that AltiKa dataset can be utilized for more accurate water level information over inland water bodies.

Modelling of hydrological and environmental flow dynamics over a central Himalayan river basin through satellite altimetry and recent climate projections

“…It is used by many researchers in river water level, discharge, and estimation of river hydraulic properties (de Oliveira Campos et al ., 2001; Birkett et al ., 2002; Papa et al ., 2012; Jarihani et al ., 2013; Duan and Bastiaanssen, 2013; Dubey et al ., 2015a; 2020). The satellite altimetry has also shown great potential in calibration and validation of hydrology and hydrodynamic models in many research studies (Chander et al ., 2014; Dubey et al ., 2014; 2015b; 2021; Gupta et al ., 2015c; Chembolu et al ., 2019). The water level data were used to generate a pseudo‐rating curve for the Ayodhya and Turtipar gauge stations and this relationship was used to convert water level into discharge.…”

“…However, not all watersheds are gauged specially in the South Asia; hence, increasing availability and coverage of satellite altimetry data provide a unique opportunity to study climate change impact on watersheds of different scale. Satellite altimetry presents an alternative approach for hydrological model calibration and validation in the absence of any valid ground observations (Leon et al, 2006;Calmant et al, 2008;Papa et al, 2010;Chander et al, 2014;Gupta et al, 2015b;2015c;Chembolu et al, 2019). Most of the well-maintained and updated gauge stations in South Asia are present over the main reaches of river basins.…”

Analysis of Retrackers’ Performances and Water Level Retrieval over the Ebro River Basin Using Sentinel-3

“…When trying to retrack waveforms over continental water bodies, the radar altimetric community has widely applied different retrackers including threshold, ice-1 and ice-2 retrackers. The robust OCOG retracker shows a consistent behavior over the different types of waveforms found in [57] with SARAL/Altika mission over different rivers and reservoirs in India. The SAMOSA retracker and its further adaptations have proven well fitting with CryoSat-2 data not only over the open-ocean and coastal zones [58], but also over ice sheets and inland waters where waveforms show specular characteristics [25,59].…”

Validation of Copernicus Sea Level Altimetry Products in the Baltic Sea and Estonian Lakes

“…where R is the directly measured distance or pseudorange between the satellite and the sea level ( Figure 3). The distance is estimated with the off-centre-of-gravity (OCOG) retracking algorithm [22,23]. SSH SA above the ellipsoid was calculated:…”