ALOS-2 ScanSAR data to be made freely available

ABraun · November 11, 2019, 8:04pm

At GEO Week 2019, Ms. Sasaki, Parliamentary Vice-Minister of Education, Culture, Sports, Science and Technology of Japan announced that the Japan Aerospace Exploration Agency (JAXA) will be providing open access to information and data from a suite of their radar satellites.

“Japan will provide free and open access to the wide-swathe observation data from the L-band radar satellites, such as ALOS (ALOS/AVINIR-2, PALSAR) and ALOS-2 (ALOS-2/ScanSAR),” stated Ms. Sasaki.

Source: http://earthobservations.org/article.php?id=392

I just created this topic to keep us updated and exchange experiences.
Although the spatial resolution of ScanSAR products is not very high, its coverage makes it interesting for studies at the regional, national and global level.

Obviously, there are things to watch out for regarding ScanSAR interferometry

SMJ.Mirzadeh · November 12, 2019, 8:44am

@ABraun Thanks to open this topic here. This kind of SAR images can be also used for the earthquake application, for example:

But I am worried about the available open-source software can be process this kind of images or not!

qglaude · November 12, 2019, 9:19am

I saw the post. These are incredible news considering the current cost of these images (650 EUR per SCANSAR image for archive, double for new acquisition).

It is quoted :

More details about the open data sharing announcement will follow shortly.

As soon as someone as some info, please share

hriston_bg · November 12, 2019, 9:47am

@SMJ.Mirzadeh I’ve used SNAP to process ALOS data. Works fine.
@ABraun Please keep this topic live - I’d like to chek how it will work for detection of ground motions in mountainous area with significant share of forests.

ABraun · November 12, 2019, 9:50am

did you also process ALOS-2 ScanSAR? I had a product once but it was incredibly large ragarding file size (as L1.1 product).

SMJ.Mirzadeh · November 12, 2019, 9:50am

@hriston_bg Thanks. Did you use SNAP to process both ScanSAR and other modes of ALOS-1&2 images?

hriston_bg · November 12, 2019, 9:52am

Sorry I’ve used ALOS-1 L1.1 provided by ESA.
ScanSAR was not of my interest.

mengdahl · November 12, 2019, 6:26pm

If the ScanSAR data becomes available we can add support for it.

SMJ.Mirzadeh · November 12, 2019, 6:42pm

@mengdahl I think that the current support of ESA in terms of services such as RUS and RSS cloudtoolbox with SNAP software are the best situations for remote sensing society especially in the InSAR field

mengdahl · November 14, 2019, 4:36pm

Thank you Sayyed we are here to support the EO communities

zhangok · November 18, 2019, 3:12am

Gerat! Looking forward to downloading these free datasets soon:)

ABraun · February 11, 2020, 12:50pm

has anyone heard news about this?

CFEgildan71 · February 20, 2020, 6:29pm

Hello

I need to make a study in a densely vegetated area in Mexico, I think ALOS-2 L-band is the correct data to obtain good results. Where can I order new acquisitions over an AOI in México? and where can I check the cost?

Thanks.

ABraun · February 20, 2020, 6:48pm

If yearly mosaics are fine for you, you could check this free source first.
https://www.eorc.jaxa.jp/ALOS/en/palsar_fnf/fnf_index.htm

Last time I checked, ALOS-2 scenes were sold between 800 and 3500 USD.
http://en.alos-pasco.com/offer/price.html

CFEgildan71 · February 21, 2020, 5:30pm

Thank you @ABraun.

I have a monitoring project over a place where a landslide has occurred in 2007.

I would like to get ALOS-2 because L-band can provide better coherence images in areas with dense vegetation.

ABraun · February 21, 2020, 5:38pm

I’m afraid such landslides will lose coherence in any wavelength, to be honest.

The amount of extreme and sudden mass movements is hard to measure by phase information. Or is it a rather creeping movement?

CFEgildan71 · February 21, 2020, 6:28pm

No, it was an abrupt landslide but we didn’t monitoring in 2007, we don’t know if it was moving slowly before the landslide, the geology department in my work wants to monitoring and identify possible risk along the river and dam. I attempted to do DinSAR with ALOS-PALSAR but I get an IFG noisy. At first, I thought the coregistration was failed, but I can Identify the landslide in the coregistered image:

I’ll try to do DinSAR changing the images with smaller bperp.

What do you think?

ABraun · February 21, 2020, 8:24pm

you can try, but it will be challenging. Maybe you compute coherence first to check if results are valid in this area.

I would try to test with other data before actually ordering ALOS data.
Parts of the ALOS archive can be accessed here

CFEgildan71 · February 24, 2020, 3:45pm

@ABraun thank you for your advice, I’ll try with sample data from the links that you share me before to order any ALOS image. I can see that somebody have complications with ALOS processing in other topics related to ALOS processing, especially to get coherent interferogram or ionospheric fringe corrections.

I have seen a study using ALOS-2 data to explore unstable areas in the slopes of the mountains in Ituango dam in Colombia and they have excellent results. The Ituango mountains have dense vegetation and they could identify 10 unstable regions despite dense vegetation, I need to do that and the landslide image I shared above corresponds to Peñitas dam.

Due I could not get good results with ALOS, I’m thinking monitoring using Corner Reflector grid and C-band like Sentinel as I show in the following image:

regards

ABraun · February 24, 2020, 3:48pm

Corner reflectors are a good thing because they produce a comparably reliable signal return. I am however no expert in this. There are some discussions in this forum on corner reflectors.