Satellite Imagery comes to SkyTruth Alerts

Given SkyTruth’s mission of using the view from space to motivate people to protect the environment, it was only a matter of time before satellite imagery would find its way into our Alerts application. With 2019 comes the ability to visually check out what’s taking place in your areas of interest (AOIs), all inside the same application that notifies you about environmental events in those areas.

Newly available imagery in Alerts comes from Sentinel-2 satellites, an Earth observation mission from the European Union’s Copernicus Program. Copernicus systematically acquires optical imagery at high spatial resolution (10 to 60 meters) over land and coastal waters, with new images available about every five days in many areas.

What you can see with 10 meter resolution imagery

The 10m resolution images from Sentinel 2 satellites should work well if you’re searching for new roads, expansion of large disturbance areas, or changes in natural boundaries. But you’ll be disappointed if you’re trying to identify tree cover or the type of vehicle that’s parked in your driveway.

In a 10m resolution image, one pixel represents a 10 meter by 10 meter area, so objects will need to be considerably larger than that for any detail to be discernible.

Here are two 10m images over a gas drilling site in Pennsylvania, taken one year apart.

Viewing satellite imagery inside SkyTruth Alerts

Most new features in Alerts require you to login. From alerts.skytruth.org, click on the  LOGIN  link in the header and follow the instructions. First time users will need to register for a new account.

NOTE: If you used our original Alerts, you’ll still need to register for an account the first time. Just remember to use the same email that you used to subscribe to AOIs in the original Alerts.

2. Identify the Area of Interest (AOI)

Start by clicking on the My Areas tab.

If you’ve already subscribed to an AOI, you can easily select it by clicking on its thumbnail.

Or, you can start a new AOI by clicking “Explore a New Area”.

3. Click the Sentinel Imagery checkbox.

4. Select your image date

Notes

  • Feel free to adjust the cloud cover or enter a date range, then click Filter to change the images that are available.
  • You can remove the alerts markers by, 1) Clicking the Alerts tab, 2) checking/unchecking the alerts you want on the map, 3) Clicking the My Areas tab to return the AOI controls.
  • If you like the AOI you’ve created, don’t forget to click Add this AOI to my list.
  • Use cloud cover percentage as a guidance. This represents the larger satellite image, which may cover substantially more area than your AOI. So it’s possible to have a low percentage of cloud cover and still have your AOI covered mostly by clouds.
  • You can add highways, towns, etc., to your image by clicking the Show Labels checkbox.

What’s next with Alerts and imagery

The true color images shown throughout this post are just part of what’s possible with satellite imagery. In addition to the red, green and blue bands that give images their true color appearance, most satellites catch additional bands that can include near-infrared, mid-infrared, far-infrared and thermal-infrared. Identifying landscape patterns and features using combinations of these spectral bands starts with additional processing by various data enhancement techniques, and is often followed by some type of classification algorithm to help understand what each feature or pattern represents. Doing this work is one of the challenges faced by SkyTruth Geospatial Analysts and other scientists around the world.

What do you think?

We’d like to know what you think about the addition of Sentinel-2 satellite images to the Alerts system: Will you use this new feature? What does it help you do? How does it fall short? We’re working to make continual improvements to Alerts and we’d love to hear from you! Send us an email at at feedback@skytruth.org.

New Year, New Alerts

We just released a new version of SkyTruth Alerts, a service that notifies you about environmental incidents in areas you care about. It’s a tool we built to help us monitor environmental events in-house, and we’ve made it freely available to the public for the last six years.

We’re excited about the capabilities of the new Alerts — we wrote a blog post about it in November — and we’re looking forward to adding new features and alerts sources in the future. Here’s a quick rundown of what you need to know to get started with the new Alerts:

I used the original Alerts. Do I need to do anything to switch?

You don’t have to do a thing to continue receiving the same alert emails you’ve always received, although you’ll notice the emails have a new format. You can still view a specific alert by clicking on its link in the email.

If you want to add or change the areas of interest (AOIs) you monitor, or fine-tune the alerts you see or get emails for (a new feature), we now ask you to create an account. We only collect your email address, which we need to send you emails. We have plans to add features in the future that will also need a user account in order for them to work.

OK, so how do I register for an account in the new Alerts?

Go to SkyTruth Alerts and select Login from the burger menu. If it’s your first time here, click the Register here link to create an account.

The original Alerts worked fine! Why did SkyTruth create a new Alerts?

Web-based software has a pretty short life-span and the first Alerts system was getting harder and harder to maintain. Additionally, SkyTruth wanted to expand the number and types of alerts that we were saving as well as work on new features such as notifying subscribers when there is a change in their AOI. It became clear that the original Alerts wouldn’t be able to handle these additions.

Does the new Alerts do everything that the original Alerts did?

Almost! We’re still working on the API that a few subscribers used to integrate alerts with other software. If you spot anything else that we missed, please let us know by emailing us at feedback@skytruth.org.

Until we have the API fixed, we’ll keep the original Alerts available at https://alerts1.skytruth.org. Note that this should only be used for redirecting the API and embedded links in KMZ/KML files. If your KMZ file contained a link to https://alerts.skytruth.org, you can still get it to work by pointing to https://alerts1.skytruth.org.

What major new features should I know about today?
  • You can filter the alerts you receive emails for.
  • You can filter the alerts shown on the map by type and date.
  • You can create AOIs that are polygon shaped.
  • You can choose a pre-defined AOI. Currently, we have states and counties ready and are working on more.
  • We’ve added or restored alerts for:
    • Oil and Gas well permits from West Virginia and Colorado
    • Florida Pollution
Can you add alerts from other websites?

Yes! Let us know what a useful source for alerts would be and we’ll consider it for the future. That email again is feedback@skytruth.org.

No NRC Reports since Nov. 18 [UPDATED]

[Update: As of Dec. 16, 2018, NRC reports are being released again.]

If you are a SkyTruth Alerts subscriber, you may have noticed that there have been no new NRC reports lately. This is because the NRC has not published any new reports since November 18. We’ve contacted them to try and find out what’s going on, and we’ll have them back in SkyTruth Alerts as soon as we can.

Big Changes Coming to SkyTruth Alerts

For the last year or so we’ve been working to revamp SkyTruth Alerts, an app we built for ourselves in 2011, and then opened up to the public a year later. The Alerts lets you see environmental incidents and notifications on a map as they are reported, and allows subscribers to sign up to receive email notifications about reported environmental incidents in areas they care about (aka “Areas of Interest” or AOIs). Technology has made a few leaps since then, so it was time for an overhaul. We’ve added some new features too. We’re excited about the changes, and we hope you will be too.  

What’s Changed?

In a lot of ways, the new SkyTruth Alerts app works the way it always has: anyone can view the map and see the latest reported alerts for a particular area. These notifications come from federal and state websites that we have “scraped” to obtain the reports. The largest source of data is the nationwide oil and hazardous materials spill reports collected by the National Response Center (i.e., NRC Reports). Anyone can sign up to receive email notifications about incidents in their AOIs.

New and Restored Sources of Alerts

As part of the Alerts revamp, we’ve restored and/or added the following sources of alerts:

  • West Virginia oil & gas drilling permits –  restored
  • Colorado oil & gas drilling permits – new
  • Florida Pollution Reports – new

Account Management

We’ve also added account management so you can update your AOIs or change your email address more easily. Signing up for an account will also let you take advantage of new tools we’ll be rolling out in the coming months (we’ll keep you posted after the launch).

New Look!

This is what SkyTruth Alerts looks like right now:

This is what you’ll see when you first open the revamped SkyTruth Alerts (subject to some possible changes over the next few weeks, as we respond to feedback and suggestions from our alpha testers):

New Features!

Here are a few of the new features we’ve added:

New Ways to Create AOIs

Right now, SkyTruth Alerts lets you create AOIs that are a square or rectangle, but that’s not always the ideal shape. In the new version, we’ve added some tools that give you a little more control: you can draw a polygon, take a “snapshot” your current map view, or select a state or county boundary from a list of pre-defined AOIs):

After you create an AOI, you can edit your AOI (or delete it and start again) before giving it a name and saving it to your My Areas list.

Filter Out the Noise

We’ve added several ways to filter what you see in Alerts, so that you can focus on what’s important to you. SkyTruth Alerts shows you the 100 most-recent incidents in your map view (double what’s shown in the current version), so filtering has the added benefit of showing you more of the types of alerts you want to see. You can filter alerts by:

Date Range

Type of Alert

Base Layers

Select from a couple of different map backdrops (“base layers”) so you can focus on what’s important to you. Below is a screenshot of SkyTruth Alerts using the “Minimal” base layer.

Alerts Within AOI Only

This can be useful if there are a lot of alerts in the surrounding area that are more recent than the alerts within your AOI.  

In the image below, there are only a few alerts are shown in the West Virginia AOI:

However, once alerts are limited to within the AOI, the picture changes:

New Ways to View Alerts Markers

In some places, there are many, many alerts in the same location. This can make it hard to move around the map because you end up clicking or tapping an alert marker when you wanted move around in the map view. It can also be hard to “grab” a particular alert marker from a stack of them.

In the first screenshot, clustering is turned on, making it easier to move around the map. Click on a cluster marker to zoom in on that area and see more alerts.

Once you’ve zeroed in on your area of interest, it can still be hard to see the forest for the trees in some locations. In the next image, clustering is turned off. You can see that there are a lot of alerts in this area, but how many exactly?

The image below shows the same area as the one above. If you click on one of the alert markers, it will “explode,” showing you all of the alerts in that location. Click on any of the exploded markers to view the report.

So when’s the Launch?

We’re getting ready to begin alpha testing in in mid-November. Lots of our current subscribers have volunteered to be testers and will be helping us put the finishing touches on the app. A big thank you to all of you who are helping us with that! Testing will last four weeks, and during that time we’ll be making continuous updates based on feedback we receive. We expect to go live with the new version by the end of the year.