MODIS/Aqua Sea Ice Extent 5-Min L2 Swath 1km, Version 4

MODIS/Aqua Sea Ice Extent 5-Min L2 Swath 1km (MYD29) contains the following fields: sea ice by reflectance, sea ice by reflectance pixel quality assurance (QA), ice surface temperature (IST), IST pixel QA, sea ice by IST, combined sea ice, latitudes, and longitudes in HDF-EOS format along with corresponding metadata. Latitude and longitude geolocation fields are at 5 km resolution while all other fields are at 1 km resolution. Version 4 (V004) MYD29 data uses Aqua/MODIS band seven instead of band six. The sea ice algorithm uses a Normalized Difference Snow Index (NDSI) modified for sea ice to distinguish sea ice from open ocean based on reflective and thermal characteristics. The only data available for Version 4 (V004) is the Golden Month, which is a sample of V004 data covering the time period 29 August 2002 (day of year 241) through 7 October 2002 (day of year 280). The Golden Month is only available by special request by contacting NSIDC User Services.

Please note that NSIDC now has a complete series of Version 5 data, which is the highest version number now available and represents the best quality of data.

MODIS/Aqua海冰范围5分钟L2扫描1公里数据集（MYD29）包含以下字段：反射率海冰、反射率海冰像素质量保证（QA）、冰面温度（IST）、IST像素QA、IST海冰、组合海冰、纬度和经度，所有数据以HDF-EOS格式存储并附带相应元数据。纬度和经度地理定位字段的分辨率为5公里，其余所有字段的分辨率均为1公里。版本4（V004）MYD29数据使用Aqua/MODIS的7波段而非6波段。海冰算法采用针对海冰优化的归一化差分雪指数（Normalized Difference Snow Index，NDSI），基于反射特性与热特性区分海冰与开阔海洋。版本4（V004）仅提供“黄金月”样本数据，覆盖时间段为2002年8月29日（年积日241）至2002年10月7日（年积日280），该样本需通过联系NSIDC用户服务特别申请方可获取。请注意，NSIDC目前已提供完整的版本5数据系列，此版本为当前可用的最高版本，代表着最优质的数据质量。