User Request Guidelines - PALSAR -


Background
The ALOS mission features a systematic observation strategy which comprises pre-launch, systematic global observation plans for all three instruments. The strategy is implemented as a top-level foreground mission and with a priority level second only to that of emergency observations.

Users of all categories (scientific and commercial users, ALOS Principal Investigators, etc.) who wish to place additional observation requests for ALOS data (via the regional ALOS Data Nodes) are strongly encouraged to align new observation requests with the JAXA observation strategy in order to avoid programming conflicts and thereby to improve individual request success rates.

PALSAR Strategy Characteristics
The observation strategy for PALSAR features observations in 4 default sensor modes, out of which three are dedicated to ascending (evening) passes, and one to desceding (morning) passes. The table below lists the mode designations as per satellite cycle for ascending and descending passes, respectively.

PALSAR operational default modes per cycle
Cycle # Start date PALSAR
Ascending Descending
1 Commissioning Commissioning
2
3 19-Apr-06 Cal / Val Cal / Val
4 4-Jun-06
5 20-Jul-06
6 4-Sep-06
7 20-Oct-06 Any mode ScanSAR HH
8 5-Dec-06 HH 34.3° ScanSAR HH
9 20-Jan-07 HH 34.3° ScanSAR HH
10 7-Mar-07 POL 21.5° ScanSAR HH
11 22-Apr-07 POL 21.5° ScanSAR HH
12 7-Jun-07 HH+HV 34.3° ScanSAR HH
13 23-Jul-07 HH+HV 34.3° ScanSAR HH
14 7-Sep-07 HH+HV 34.3° ScanSAR HH
15 23-Oct-07 Any mode ScanSAR HH
16 8-Dec-07 HH 34.3° ScanSAR HH
17 23-Jan-08 HH 34.3° ScanSAR HH
18 9-Mar-08 HH 34.3° ScanSAR HH
19 24-Apr-08 HH+HV 34.3° ScanSAR HH
20 9-Jun-08 HH+HV 34.3° ScanSAR HH
21 25-Jul-08 HH+HV 34.3° ScanSAR HH
22 9-Sep-08 HH+HV 34.3° ScanSAR HH
23 25-Oct-08 Any mode ScanSAR HH
24 10-Dec-08 HH 34.3° ScanSAR HH
25 25-Jan-09 HH 34.3° ScanSAR HH
26 12-Mar-09 POL 21.5° ScanSAR HH
27 27-Apr-09 POL 23.1° ScanSAR HH
28 12-Jun-09 HH+HV 34.3° ScanSAR HH
29 28-Jul-09 HH+HV 34.3° ScanSAR HH
30 12-Sep-09 HH+HV 34.3° ScanSAR HH
31 28-Oct-09 Any mode ScanSAR HH
32 13-Dec-2009 HH 34.3° ScanSAR HH
33 28-Jan-2010 HH 34.3° ScanSAR HH
34 15-Mar-2010 HH 34.3° ScanSAR HH
35 30-Apr-2010 HH+HV 34.3° ScanSAR HH
36 15-Jun-10 HH+HV 34.3° ScanSAR HH
37 31-Jul-10 HH+HV 34.3° ScanSAR HH
38 15-Sep-10 HH+HV 34.3° ScanSAR HH
39 31-Oct-10 Any mode ScanSAR HH
40 16-Dec-10 HH 34.3° ScanSAR HH
41 31-Jan-11 HH 34.3° ScanSAR HH
42 18-Mar-11 POL 21.5° ScanSAR HH
43 3-May-11 POL 23.1° ScanSAR HH
Satellite cycle start dates based on launch in January, 2006

As a full global coverage cannot be completed during a single 46-day cycle, acquisitions are undertaken on a regional basis, which varies from cycle to cycle. For detailed overviews of which specific regions that are programmed for acquisition during a given cycle, click on the links below:

User Guidelines
Users of all categories (scientific and commercial users, ALOS Principal Investigators, etc.) who consider making additional observation requests for ALOS data (via the regional ALOS Data Nodes) are strongly encouraged to align new observation requests with the JAXA observation strategy in order to avoid programming conflicts. As the observation strategy is implemented with higher priority than general user requests, alignment will also result in improved individual request success rates.

In order to take advantage of existing acquisitions already planned within the observation strategy, and to avoid introducing conflicting requests, please go through the following simple procedure:

Step 1. Check whether your area of interest is already scheduled for acquisition.

  • Find out the cycle number for your preferred time period in the table above. Keep note of the prevailing sensor mode.
  • Consult the ascending or descending cycle plots to determine whether your area already is scheduled during the cycle in question.

Step 2, Case 1. Your area of interest is scheduled.

  • No action is required from your side. The area is scheduled for acquisition with the default mode indicated for the cycle in question.
  • Requests for acquisitions with a sensor mode deviating from the prevailing default mode will be rejected.

Step 2, Case 2. Your area of interest is not scheduled.

  • You need to submit a new acquisition request. You are strongly encouraged to request the default sensor mode indicated in the table for the cycle in question.
  • Requests for acquisitions with a sensor mode deviating from the prevailing default mode will not be rejected, but are nonetheless not recommended as they may introduce unforeseen conflicts.

Step 2, Case 3. You are unsure whether your area of interest is scheduled; it is located close to the border of a scheduled and non-scheduled region.

  • You are recommended to submit a new acquisition request, keeping to the default sensor mode for the cycle in question.
  • Requests for acquisitions with a sensor mode deviating from the prevailing default mode will be rejected.

Step 3. Requests for non-default mode acquisitions.

  • One satellite cycle per year (ascending cycles 7, 15, 23) is left open with no default mode defined, to accommodate user reqests for non-default mode acquisitions.

Miscellaneous information

  • ALOS completes 671 orbits during a 46-day satellite cycle
  • 8 satellite cycles per year (368 days)
  • Cycle 1-2: Commissioning phase
  • Cycle 3-6: Calibration/Validation phase
  • Cycle 7+: Operational acqusitions according to the Observation Strategy
  • The estimated average success rate for acquisitions planned within the observation strategy is about 80%.