{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,18]],"date-time":"2025-11-18T09:19:37Z","timestamp":1763457577202,"version":"build-2065373602"},"reference-count":20,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2016,12,9]],"date-time":"2016-12-09T00:00:00Z","timestamp":1481241600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>This paper describes approaches to retrieve important aerosol results from the strong lidar return signals that are received by the space-borne CALIPSO lidar system after reflecting off-ocean surfaces. Relations, from which the theoretically expected values of area under ocean surface returns can be computed, are presented. A detailed description of the lidar system response to the ocean surface returns and the processes of sampling and averaging of lidar return signals are provided. An effective technique that reconstructs the lidar response to surface returns\u2014starting from down-linked samples\u2014and calculates the area under it, has been developed and described. The calculated area values are validated after comparing them to their theoretically predicted counterpart values. Methods to retrieve aerosol optical depths (AODs) from these calculated areas are described and retrieval results are presented, including retrieval comparison with independent AOD measurements made by an airborne High Spectral Resolution Lidar (HSRL) that yielded quite good agreement. Techniques and results are also presented on using the spectral ratios of the surface response areas to determine spectral ratios of aerosol round-trip transmission and AOD spectral difference, without need of a specific\/accurate ocean-surface reflectance model.<\/jats:p>","DOI":"10.3390\/rs8121006","type":"journal-article","created":{"date-parts":[[2016,12,9]],"date-time":"2016-12-09T10:15:15Z","timestamp":1481278515000},"page":"1006","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Aerosol Retrievals from CALIPSO Lidar Ocean Surface Returns"],"prefix":"10.3390","volume":"8","author":[{"given":"Srikanth","family":"Venkata","sequence":"first","affiliation":[{"name":"Department of Electrical and Computer Engineering, University of Arizona, Tucson, AZ 85721, USA"}]},{"given":"John","family":"Reagan","sequence":"additional","affiliation":[{"name":"Department of Electrical and Computer Engineering, University of Arizona, Tucson, AZ 85721, USA"}]}],"member":"1968","published-online":{"date-parts":[[2016,12,9]]},"reference":[{"key":"ref_1","unstructured":"Hostetler, C.A., Liu, Z., Reagan, J., Vaughan, M., Winker, D., Osborn, M., Hunt, W.H., Powell, K.A., and Trepte, C. (2006). CALIOP Algorithm Theoretical Basis Document."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2310","DOI":"10.1175\/2009JTECHA1281.1","article-title":"Overview of the CALIPSO mission and CALIOP data processing algorithms","volume":"26","author":"Winker","year":"2009","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1211","DOI":"10.1175\/2010BAMS3009.1","article-title":"The CALIPSO mission: A global 3D view of aerosols and clouds","volume":"91","author":"Winker","year":"2010","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_4","unstructured":"Srikanth, L.V. (2012). Aerosol Retrievals from CALIPSO Lidar Ocean Surface Returns. [Master\u2019s Thesis, University of Arizona]."},{"key":"ref_5","unstructured":"Hunt, W. Personal communications."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1214","DOI":"10.1175\/2009JTECHA1223.1","article-title":"CALIPSO lidar description and performance assessment","volume":"26","author":"Hunt","year":"2009","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"5327","DOI":"10.1364\/OE.15.005327","article-title":"The depolarization-attenuated backscatter relation: CALIPSO lidar measurements vs. theory","volume":"15","author":"Hu","year":"2007","journal-title":"Opt. Express"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1117\/12.55776","article-title":"Space-borne lidar remote sensing techniques aided by surface returns","volume":"30","author":"Reagan","year":"1991","journal-title":"Opt. Eng."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"838","DOI":"10.1364\/JOSA.44.000838","article-title":"Measurement of the roughness of the sea surface from photographs of the sun\u2019s glitter","volume":"44","author":"Cox","year":"1954","journal-title":"J. Opt. Soc. Am."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1109\/TAP.1966.1138626","article-title":"A note on the theory of scattering from an irregular surface","volume":"14","author":"Kodis","year":"1966","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"449","DOI":"10.1109\/TAP.1968.1139220","article-title":"Rough surface scattering based on the specular point theory","volume":"14","author":"Barrick","year":"1968","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"5550","DOI":"10.1364\/AO.37.005550","article-title":"Lidar in-space technology experiment measurements of sea surface directional reflectance and the link to surface wind speed","volume":"37","author":"Menzies","year":"1998","journal-title":"Appl. Opt."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Lancaster, R.S., Spinhirne, J.D., and Palm, S.P. (2005). Laser pulse reflectance of the ocean surface from the GLAS satellite lidar. Geophys. Res. Lett., 32.","DOI":"10.1029\/2005GL023732"},{"key":"ref_14","unstructured":"Klein, M.V., and Furtak, T.E. (1986). Optics, John Wiley and Sons. [2nd ed.]."},{"key":"ref_15","first-page":"D10S11","article-title":"Variability of aerosol and spectral lidar and backscatter and extinction ratios of key aerosol types derived from selected aerosol robotic network locations","volume":"110","author":"Cattrall","year":"2005","journal-title":"J. Geophys. Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"4317","DOI":"10.5194\/amt-7-4317-2014","article-title":"Looking through the haze: Evaluating the CALIPSO level 2 aerosol optical depth using airborne high spectral resolution lidar data","volume":"7","author":"Rogers","year":"2014","journal-title":"Atmos. Meas. Tech."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"6734","DOI":"10.1364\/AO.47.006734","article-title":"Airborne high spectral resolution lidar for profiling aerosol optical properties","volume":"47","author":"Hair","year":"2008","journal-title":"Appl. Opt."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Josset, D., Pelon, J., Protat, A., and Flamant, C. (2008). New approach to determine aerosol optical depth from combined CALIPSO and CloudSat ocean surface echoes. Geophys. Res. Lett., 35.","DOI":"10.1029\/2008GL033442"},{"key":"ref_19","unstructured":"Guilmo, A., Tyo, J.S., and Reagan, J. (2014, January 3\u20135). CALIOP high resolution IRF modeling based on in-situ observations and application to AOD retrieval. Presented at 2014 Fall AGU Meeting, San Francisco, CA, USA."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"18698","DOI":"10.1364\/OE.22.018698","article-title":"Lidar extinction to backscatter ratio of the ocean","volume":"22","author":"Churnside","year":"2014","journal-title":"Opt. Express"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/8\/12\/1006\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:28:16Z","timestamp":1760210896000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/8\/12\/1006"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,12,9]]},"references-count":20,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2016,12]]}},"alternative-id":["rs8121006"],"URL":"https:\/\/doi.org\/10.3390\/rs8121006","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2016,12,9]]}}}