Earthdata Forum

Hello everyone,

I am currently working on a study over an area in the Amazon, defined by the following area: [-78.246513,-2.287699,-77.990836,-2.093647].

When I look at the KMZ of planned acquisitions over this area, I see both ascending and descending passes are expected.
However, when searching for available data on ASF and EarthData, I can only find descending data, which seems consistent with the KMZ file NISAR_Feb2026_ReleasedData-20260305.

My questions are:
- Why are the ascending data not available?
- Are they expected to be released at a later stage, or are they not being acquired/processed for some reason?

Any insight would be greatly appreciated.

Thanks in advance!

Nathan Paillou

Hello Nathan,
The NISAR Data User Guide provides a coverage map for the February 2026 pre-calibration (sample) data release. Comparing a Vertex search using the coordinates of your study area to this coverage map, it doesn't appear that any ascending acquisitions over your AOI were included in the sample dataset.




The global, fully-calibrated NISAR data are scheduled to be released in July of this year and will include observations over your study area in Ecuador. Any changes to this data release timeline will be documented in the Data User Guide.

Thank you.

Dear Bill Hauer,

Thank you for your clarification.

I understand that, both on ASF and in the February 2026 NISAR data release, there are currently no ascending acquisitions available over my study area. However, when I look at the NISAR reference observation plan (KMZ file available on the NASA website:
https://science.nasa.gov/mission/nisar/data/), it clearly indicates that ascending acquisitions are planned over this region.

From my understanding of the mission documentation, this observation plan represents the intended nominal acquisition strategy, i.e. the coverage that should be achieved once the mission is fully operational and calibrated, rather than the subset currently released.

At the same time, the February 2026 dataset corresponds only to a pre-calibration sample, covering acquisitions between October 17, 2025 and January 20, 2026, and does not necessarily include all planned tracks or geometries (ascending/descending) for every location.

Given this context, could you please confirm whether my interpretation is correct:
- the ascending acquisitions shown in the observation plan do exist (or are planned) but were simply not included in the pre-calibration release?
- they are expected to become available with the fully calibrated global data release (around June–July 2026)?

Or alternatively, should I understand that these ascending acquisitions have not yet been acquired over this area?

Thank you very much for your help.

Best regards,

Nathan Paillou

The Data Release Timeline describes the past and future release schedule in more detail.

- the ascending acquisitions shown in the observation plan do exist (or are planned) but were simply not included in the pre-calibration release?

Correct. NISAR has been regularly acquiring data over your area of interest (and everywhere else in the acquisition plan) since Sep 2025. Only a limited subset of that data was made available in February.

- Are they expected to be released at a later stage, or are they not being acquired/processed for some reason?

Yes, they will be released at a later stage. Starting in July and going forward, all newly-acquired data will be made available to the public as soon as it is acquired.

Data acquired Sep 2025 - Jul 2026 will be gradually made available over the second half of 2026.