@article{fdi:010060851,
  title = {{C}alibration of {E}nvisat radar altimeter over {L}ake {I}ssykkul},
  author = {{C}retaux, {J}. {F}. and {B}erge-{N}guyen, {M}. and {C}almant, {S}t{\'e}phane and {R}omanovski, {V}. {V}. and {M}eyssignac, {B}. and {P}erosanz, {F}. and {T}ashbaeva, {S}. and {A}rsen, {A}. and {F}und, {F}. and {M}artignago, {N}. and {B}onnefond, {P}. and {L}aurain, {O}. and {M}orrow, {R}. and {M}aisongrande, {P}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}his study presents the results of calibration/validation ({C}/{V}) of {E}nvisat satellite radar altimeter over {L}ake {I}ssykkul located in {K}yrgyzstan, which was chosen as a dedicated radar altimetry {C}/{V} site in 2004. {T}he objectives are to estimate the absolute altimeter bias of {E}nvisat and its orbit based on cross-over analysis with {TOPEX}/{P}oseidon ({TIP}), {J}ason-1 and {J}ason-2 over the ocean. {W}e have used a new method of {GPS} data processing in a kinematic mode, developed at the {G}roupe de {R}echerche de {G}eodesie {S}patiale ({GRGS}), which allows us to calculate the position of the {GPS} antenna without needing a {GPS} reference station. {T}he {C}/{V} is conducted using various equipments: a local {GPS} network, a moving {GPS} antenna along the satellites tracks over {L}ake {I}ssykkul, {I}n {S}itu level gauges and weather stations. {T}he absolute bias obtained for {E}nvisat from field campaigns conducted in 2009 and 2010 is between 62.1 and 63.4 +/- 3.7 cm, using the {I}ce-1 retracking algorithm, and between 46.9 and 51.2 cm with the ocean retracking algorithm. {T}hese results differ by about 10 cm from previous studies, principally due to improvement of the {C}/{V} procedure. {A}part from the new algorithm for {GPS} data processing and the orbit error reduction, more attention has been paid to the {GPS} antenna height calculation, and we have reduced the errors induced by seiche over {L}ake {I}ssykkul. {T}his has been assured using cruise data along the {E}nvisat satellite track at the exact date of the pass of the satellite for the two campaigns. {T}he calculation of the {E}nvisat radar altimeter bias with respect to the {GPS} levelling is essential to allow the continuity of multi-mission data on the same orbit, with the expected launch of {SARAL}/{A}ltika mission in 2012. {I}mplications for hydrology in particular, will be to produce long term homogeneous and reliable time series of lake levels worldwide.},
  keywords = {{A}bsolute altimeter calibration ; {E}nvisat ; {GPS} ; {C}ross-over analysis ; {G}eophysical corrections ; {L}ake {I}ssykkul ; {KIRGHIZSTAN}},
  booktitle = {},
  journal = {{A}dvances in {S}pace {R}esearch},
  volume = {51},
  numero = {8},
  pages = {1523--1541},
  ISSN = {0273-1177},
  year = {2013},
  DOI = {10.1016/j.asr.2012.06.039},
  URL = {https://www.documentation.ird.fr/hor/fdi:010060851},
}