Extent and concentrations of sea ice in the Earth's polar regions are sensitive indicators of global climate change. ASPeCt (Antarctic Sea Ice Processes and Climate) ship-based ice observations, made during the Sea Ice Mass Balance in the Antarctic (SIMBA) and the Sea Ice Physics and Ecosystem eXperiment (SIPEX) IPY cruises during September–October 2007, are used to validate satellite remote-sensing measurement of ice extent and concentration. Observations conducted during the two cruises in the austral end-of-winter–beginning-of-spring season of 2007 study the varied sea-ice types at and inside the ice edge of west (90° W) and east (120° E) Antarctica. Time series remote-sensing images of AMSR-E (Advanced Microwave Scanning Radiometer–Earth Observing System) ice concentration and ice extent and NIC (National Ice Chart) ice edges were obtained for the 2006–2008 periods bracketing the period these cruises were conduced. The total sea-ice cover, bounded by the outer ice edges, around the entire continent for 2006–2007 and 2007–2008 from AMSR-E and NIC were compared. Results indicate the maximum difference between the two datasets was 2.16 × 106 km² on 28 November 2007 and 2.68 × 106 km² on 15 January 2008, where AMSR-E-derived areas were lower than the NIC values. Sea-ice concentration comparison between passive microwave satellite and ASPeCt observations during the inbound and outbound track of the two cruises was also conducted. Generally, regions where we have concentrated pack ice of the data indicated good correlation; however, regions at the marginal zone of the data indicated poor correlation, with AMSR-E’s tendency in underestimating the low ice concentrations as observed from the vessels. The ship-observed values of the outer boundary at the ice edge were more consistent with NIC charts than they were with AMSR-E-derived values, but were only observed on the inbound and outbound legs of the two cruises (four observations). These observations are however consistent with other studies that also compared passive microwave and ship observations, as well as the AMSR-E tendency for underestimation of low ice concentrations compared with ship-observed values.