Modeling Remote Sensing Satellite Collection Opportunity Likelihood for Hurricane Disaster Response     

《制图学和地理信息科学》2013,40(1):7-15

State and local agencies involved in emergency response to natural disasters such as hurricanes have explicitly indicated they need imagery covering the disaster area within three days of the event; and more desirably within 24 hours of the event. Airborne image collections have often been used but suffer from several problems, most noticeably the collection time (days or week) required for larger areas. The use of remote sensing satellites carrying high spatial resolution sensors has often been touted as the logical response for rapidly collecting post-disaster event imagery for emergency response. Unfortunately, satellites are maintained on fixed orbits. The repeat interval for remote sensing satellites carrying high spatial resolution sensors, even with pointable sensors, is on the order of several days, depending on the latitude for the disaster event. Fortunately, more than one satellite carries high spatial resolution imagery. This combination of requirements and restrictions may result in either a relatively high (or low) likelihood of collecting imagery within the three-day window of opportunity. This research investigated the likelihood of collecting imagery over a hurricane disaster area based on the orbital cycles of three high spatial resolution imaging satellites. Using the spatial-temporal distribution of historic hurricane landfall locations as a proxy for the probability distribution of future hurricanes by latitude, the "visibility" of each landfall location to future satellite imaging opportunities was determined. The results indicate that the likelihood of collecting imagery within one day of the event varied between 17 and 39 percent by relying on one satellite image provider. However, if either of three satellite imagery sources (i.e., Ikonos-2, Quickbird-2, and Orbview-3) could be used, then the likelihood increased to 61 percent. By relying on three satellite imagery providers there is a likelihood of between 94 and 100 percent of collecting imagery within two or three days, respectively, after the event.  相似文献   

The usefulness of Nimbus CZCS imagery in the South-Western Indian Ocean     

《African Journal of Marine Science》2013,35(1):261-269

Aspects of the South-West Indian Ocean circulation, such as currents and their meanders and eddies, are chromatographically identified in the area 20–40°S, 30–40°E from the level-2 images of the Nimbus-7 Coastal Zone Colour Scanner (CZCS). Notwithstanding the inescapable obstruction presented by the extensive cloud-cover over this subtropical region, CZCS imagery is especially useful in areas of weak thermal gradients. Other regions where colour imagery is fruitful are those where oceanographic features originate from deep-sea water masses with large phytoplanicton concentrations or where coastal waters with distinct colour signals are entrained.  相似文献