What's up with ASTER? – Transcription
Next we have Danielle.
I’m Danielle Golon, I’m a specialist for ASTER. I was looking into ASTER data, how they use the data, and how OpenStreetMap uses it. I came across the OSM online community, and a lot of confusion and questions and general things where people were like, I don’t understand what ASTER is. I wanted to come here to answer those questions. Do you know what ASTER data is? Have you used it before? Perfect.
So today, I’m going to give a brief description into LP DAAC, information about ASTER, and how to access the data.
So what is NASA’s LP DAAC? We’re the Land Processes Distributed Active Archive Center. And we have been around since the 1970s.
And we are using the planning and sensing datasets to user community. We process data, archive data, and show the users how to apply and access data.
So we have a lot of data available.
The server reflection data, temperature, all kinds of data. If you are interested in learning about the land, we have data that is available, or we are getting more in the future.
And we are providing a variety of temporal and spatial processes, and these are things that if you are interested in, keep checking in with the LP DAAC.
Where did the nearest data come from? Our close closest is VEERS. And with VEERS and motes, we are seeing lesser picture and more detail.
And we are on-board TERA, it is a sensor that is turned on to capture data. It is giving more detail in a smaller area.
And then we also have community products, these are derived from one or more NASA earth observing systems, this is an ASTER-global dataset, and then we have projects that expand our understanding of the earth through our existing satellite measurements.
It is cool, we are re-using the data in different unique and different ways. And these products cover vicinity, vegetation, rainfall, and population, and lot more down the pipeline.
Today, we will focus on ASTER data. If you are interested, please stop and talk to me, or go to the website to learn more.
So, first, it is important to note that ASTER is the Advanced Spaceborne Thermal Emission and Reflection Radiometer, and it is in a lot of partnerships with other organizations, and previously ASTER scenes cost money to download. As of April 1, 2016, all data is available to the public at no cost.
So some ASTER fast-facts, it was launched on the TERA satellite in 1999, the data is available from 2000-present, and it has three telescopes. The first is a 15-meter telescope.
The short wave infrared is a 30-meter telescope, and the last was retired in 2008. However, the data prior to this date is still valid and used for geological applications.
And then we have the thermal infrared, or tier, 90-meter telescope, that captures data at night.
So ASTER is useful in a variety of applications, including understanding what minerals are on the surface of the earth, observing changes to a city over time, the health of vegetation, and to actively monitor 1,540 volcanos around the world, and more applications as well.
Okay, so ASTER data coverage, this is a map of the coverage from March 2000 to May 2017, that contains less than 20 percent cloud coverage. We are covering a lot of land surface on the earth. And many of these areas, the orange areas, have been covered more frequently than others.
So, as I mentioned, this is because ASTER has to be told to turn on to capture data.
It is also a pointable sensor, advantageous, as it moves across, it can move and point it’s telescopes to capture data, it does not need to be directly over the data it is tasked to capture. And on the screen, it is an infrared L-1A, or expedited image, of the Red River In Coalfax, Louisiana, this was captured in 2016 after days of rain and tornadoes impacked the areas. This is an expedited data source. This is beneficial for capturing the aftermath after natural disasters. They are available after an hour of capture, but it can take up to 48 hours. It is useful during ways of OpenStreetMap communities, during mapathons, to hit areas that are hit by natural disasters. As soon as it is taskable, it points the telescopes, it doesn’t have to wait 16 days to capture. And In Joplin, Missouri, we can see the damage from a tornado in 2011. The left is before the tornado. On the left is the image right away, and right is a little later. We can see how big the tornado track was, where it went, and the areas hit the hardest. Another ASTER product is the corrected data. This is another product with geometric and radiometric corrections to the data, and an ASTER geotip that can be added to your favorite GIS program and can be viewed instantly and worked with immediately, for whatever telescopes that were used to capture the scene at the time. The spatial resolution may be a little lower than what you are used to working with. But in this image of London, if you can see this, a bunch of features are traceable. You can see the river and different parts, and the freely available data can be used in mapathon events to draw areas that are lacking a lot of data, or have outdated data. And then, finally, we have the ASTER global additional elevation model, or ASTER version two data. This is a freely-available global elevation dataset that covers pole to pole coverage at 30-meter resolution. I know that, on the ASTER Wiki, for OpenStreetMap, it is suggesting that version one is the most recent. But version two came out in 2011, version one was out from 2009. And with each new version of data, the additional ASTER data is laid on to the previous scene for more coverage. And, as diversion one was composed of 1.2 million scenes, and 2 is composed of 1.5 million scenes, ASTER 1 had limitations that limited its usefulness for navigation in certain areas, version two was created to address these moments. It provides improved coverage, spatial resolution, and water masking, and it gives improvement over version one. But we believe that there are artifacts that could exist. And there are citation and distribution requirements for ASTER VM version two, specifically when you download the data, we ask that you tell you what your research interest is. There’s a drop-down box of a couple different categories, we want to show you what the data is used for. If you are studying health or ecosystems, it is for those types of things. And for presenting and publishing the data, you have to include ASTER VM as a product of NASA. And the exciting thing, ASTER version three is coming in, mid-2018 to release it. And as version two was an improvement over one, version three will give 350,000 more scenes, water delineation. And the most important thing to know, for version three, it will not have the redistribution and citation policies that version two had. It had no limitations or restrictions. Before we talk about how to download the data, I will talk about how to capture the benefits. All ASTER data is available at no-cost, and it is aimed to cover natural disasters more quickly, and this is useful for tracing larger features such as forests, parks, coastlines, and buildings. And you can even see the hospital lines, after the tornado, you can see it in the ASTER data. They have a lot of data on islands and volcanos. If you are interested, check it out. Some are plug-and-play, GIS technology. So you don’t have to worry about anything, just drop and go. How do you vet this data? If you are interested in any ASTER data, we recommend NASA earth data search. If you were using reverb, it is retired at the end of the year. So we definitely recommend the user data search as it is going to be its replacement. It is relatively user-friendly, it provides previews of the browsers so you know what you get before you download the data, if that is available. If you are interested in obtaining elevation data right now, I explore the global data explorer, this is where you get GDAX version two data. Here, we can see Boulder and the surrounding areas, when you click and download this data. GDX is in the process of being de-commissioned, it will not be around forever. If you want to get version two right now, you are interested in ASTER data after this talk, this is the best place to go and obtain that mosaic data. And in the future, when ASTER version three is released, I recommend a brand new application, released recently, the application for extracting and exploring analyses and examples. This allows you to extract SRT information currently, and will allow you to download the ASTER version three data when available. We have the input form. So here, there you go. You can name your file, so anything you download will have the name attached to it, easy for file management. You can upload or draw your own file system, and if you have specific points, you can do that as well. Put in your time series information, and the layers you are interested in. We have a lot of NASA products, we are adding more non-NASA-specific products in the future. And then, you will submit your file formats, and then also the projection that you want the mosaic data to be in. Once the request is completed, you put the box into Whisper for looking at polygons, and then you can look at temperature data, and what point was this temperature, you can filter by quality information, it is a great tool. Once the request is completed, you will see the files, including a JSON file, so you can share – if you are in Boulder and your colleague is in Washington, D.C., you can send the JSON file to them so they can search in the same parameters. And this is in Boulder and the surrounding area, this is SRT data, but this is the output mosaic file. This was a lot of scenes to create this one image, it did it seamlessly, if you are running a project and you did it early in the morning – That brings me to the end of the presentation. If you have questions, please contact our user services team, and feel free to sign up for our listserv. I send out updates on the data, tools, how it is used, tutorials, and videos twice a month. If you are using ASTER data, or data distributed by the LP DAAC, please stop me during the conference, I love to hear how you are using our data. Any questions?
You mentioned the issues with the first ASTER, I was wondering if you can elaborate more, or if there are needs that you have besides just more coverage.
Some of the issues, the website explains the issues in detail, you have the documentation that goes into it. You don’t have it for the elevation unit. You have documents on our website that shows what the issues are, where they are, and how ASTER version two was fixing those issues. So that is probably the best place to check on it, because things happen in different areas, it depends on how much to scale you are in your elevation.
For the original ASTER data, there was the Japanese website where you could download the whole thing, and now we are redirected to non-intuitive websites, where you take an area, that is too much, wait, we will send an email. Why are they just an FTP site, or an Amazon web service bucket? How do I get all it the data?
If you want all the data, it depends on which ASTER product you want, and also depends on the file size you interested in. If you are specifically interested in certain types of ASTER data, they are in the data pool, that you can just point a tool to the data pool and download everything that comes in. That is a great way to do it. There is also the Earth Data Search, you can add in every single thing and download it all at once. It depends if you want – do you want the entire global, everything that we’ve got?
(Speaker far from mic).
Yeah, for that, I would recommend Earth Data Search, you can download everything at once.
So the level, the entire worlds.
It will be a huge file, and that is part of –
I will give you my card, if you have questions, you can call me. Any other questions?
I have a question about the collection of data for elevations of buildings.
As far as I know, yes. It should.
And then will – (speaker far from mic).
Right. Yeah, definitely, and we can send the presentation on OpenStreetMap. All right? If we send the presentation, it will be online, right?
Thanks, let’s give a hand for Danielle. Live captioning by Lindsay @stoker_lindsay at White Coat Captioning @whitecoatcapx.