|
|
 |
| Method of ASTER Sensor data acquisition |
|
|
ASTER Sensor has several unique operational limits. Given such limits, ASTER Project has developed an observation scenario and schedule which enable the Sensor to be efficiently operated for effective data acquisition. The following is a general View of how to acquire ASTER data.
|
|
| ASTER observation scenario |
|
|
| >> |
ASTER Sensor now acquires data as requested for observation by ASTER Science Team members as well as pre-registered users and institutions including ARO users. ASTER Sensor is unique in that all observation data are acquired as requested by users (but such desired data will not always be acquired unless requested to do so).
ASTER Data Acquisition Requests may be divided into the following three categories, depending upon the user type and purpose of data utilization:
1) DAR (Data Acquisition Request)
This is the request to obtain data from relatively small-area targets. ARO users can submit fall under this category. The area of targets for which DAR can submit is specified for each user, with maximum 40,000km2 allocated to our ARO users, including that coverable by repetitive observation.
2) STAR (Science Team Acquisition Request)
This is the request to be submitted after approved by an ASTER Science Team member or members as part of ASTER Science Team activities. Its objectives include observation of local areas and extensive data acquisition from specific areas as well as time-series acquisition of data to observe areas of greater importance for ASTER Project.
STAR is further divided into the following three subcategories:
i) Local STAR
This category of STAR is a type of request mainly used for the purpose of ASTER data validation/calibration. When a natural disaster including volcano eruption takes place, a local STARbased Data Acquisition Request is also submitted for emergency observation.
ii) Regional STAR
This category of STAR is a type of request submitted for regions subject to wide-area/time-series observations conducted as part of ASTER Science Project. Each data acquisition region has a research theme, which will be implemented by a Japanese or/and U.S. ASTER Science Team member or members.
iii) Global STAR
This category of STAR is a type of request to obtain whole-globe land-area data for preferable observation conditions (including the solar height, cloud coverage, and gain setting) at least once during the period of mission operation as aimed at by ASTER Project. This Data Acquisition Request gives three different levels of priority to observation, depending upon its importance, for available prioritybased observation.
3) ETR (Engineering Team Request)
This is the request submitted for the purpose of obtaining engineering data for ASTER equipment maintenance. Despite its position to be given top priority due to great importance of ETR, this Data Acquisition Request is submitted only by Sensor equipment management personnel but never by an ARO user.
Any observation data acquired through Data Acquisition Requests can be obtained by all users, whoever they may be. |
|
|
| ASTER observation schedule |
|
|
| >> |
Various Data Acquisition Requests submitted are ordered in terms of priority by Science Project and put together into One-Day Observation Schedule (ODS: One Day Schedule) by in-ASTER Ground Data System (ASTER GDS) Scheduler. This Schedule is prepared as Optimized Schedule after considered such as for observation parameters established in Data Acquisition Request, cloud forecast data for that day, and limits on ASTER operation. Even submitted Data Acquisition Request may sometimes remain unobserved if any competitive Data Acquisition Request has been submitted or operational limits on Sensor shall apply. (Particularly when special observation parameters have been established, be careful since it will be harder to obtain data. ) In case synchronous observation is scheduled such as for field campaigns, as much coordination as possible is arranged so that applicable Data Acquisition Requests may be observed after the observation schedule is developed. Any scheduled synchronous observation must, therefore, be applied for by the Principal Investigator to ARO Office not less than 40 days before the synchronous observation date. (Even when applied for beforehand, observation may be unlikely such as due to operational limits on ASTER.)
Although Data Acquisition Requests have their deadline (48 hours before observation), post-deadline reception is also allowed as "Urgent" data to judge whether or not it should be accepted, depending such as upon their urgency, importance, and influences on other observations. However, if ARO users ? wish to submit "Urgent" data acquisition requests, it is necessary to apply to ARO Office beforehand.
|
|
|
|
|