We’re NOAA scientists Mitch Goldberg and Tom Wrublewski, here to answer questions about NOAA’s newest weather satellite JPSS-1, which is scheduled to launch on November 10, to capture the global weather data needed for your local, 3-7 day forecast -- and much more. Ask us anything!


Hi Reddit! We are NOAA scientists Dr. Mitch Goldberg and Tom Wrublewski with the Joint Polar Satellite System (JPSS) program. For years, we have been working with our colleagues to prepare JPSS-1, our next-generation polar-orbiting satellite, for its trip into space. Now, the big day is almost here!

NOAA’s National Weather Service relies on critical data from polar-orbiting satellites like JPSS-1, or NOAA-20, as it will be known once it reaches orbit. In fact, 85% of the data that feed weather forecast models come from polar-orbiting satellites. Orbiting 512 miles above the earth at 17,000 miles-per-hour, JPSS-1 will collect critical weather and environmental data allowing us to better predict the path of severe storms like Hurricanes Irma and Maria, and track wildfires like those those in Northern California, providing timely information for FEMA and local emergency responders.

We’re excited for the launch of JPSS-1 and its five, state-of-the-art instruments that will monitor Earth's atmosphere, land and oceans. We’re looking forward to taking your questions about the satellite’s upcoming launch and capabilities. We'll be here from 1-3 p.m. ET: Ask us anything!

P.S. You can follow us on twitter @NOAASatellites or visit our website at https://www.nesdis.noaa.gov/JPSS-1 to stay up to date on the preparations for launch

We are out of time, but we'd like to thank you for taking the time to join us for this Reddit AMA and asking your questions about NOAA's JPSS-1 satellite. We appreciate the variety of great questions, as well as the helpful responses from other participants. I think we all learned a little something this afternoon! If you’d like to learn more about JPSS satellites, visit the following sites:

NOAA Satellite and Information Service: https://www.nesdis.noaa.gov/

JPSS-1 Launch Page: https://www.nesdis.noaa.gov/JPSS-1

Joint Polar Satellite System: http://www.jpss.noaa.gov/

JPSS - FAQs: http://www.jpss.noaa.gov/faq.html

Can you discuss what kinds of instruments are aboard JPSS-1 and how they improve upon older ones? How do they contribute to weather forecasting?


Thanks for your question! We have three critical instruments for weather forecasters that will be flying aboard JPSS-1---they are VIIRS, CrIS and ATMS. These are considered essential to fulfilling “key performance parameters”---which means that without the data these instruments provide, NOAA’s National Weather Service can’t do its job in creating the forecast.

VIIRS has more channels, higher resolution, and unique “day-night” band that wasn’t available on earlier NOAA polar-orbiters. ATMS uses microwaves to “see” Earth, so it can see into, through, and below clouds, which is a tremendous advantage. It also has an improved motor-scan system that should lead to a longer life in orbit.

CrIS has over 2200 channels--each of which “sees” a different part of the atmosphere. This is a huge increase---more than a hundred times more than we had before with previous infrared sounders. This means we have significantly increased our ability to see vertically (by a factor of 6), in detail, through the atmosphere. We can see details of the atmosphere in 1-2 kms. Previous infrared sounders provided data at 3-6 kms.

Here’s a link to a quick overview of the spacecraft and instruments on our launch page: https://www.nesdis.noaa.gov/content/jpss-1-spacecraft but you can also find more in-depth information at http://www.jpss.noaa.gov/print.html


What are the coolest online resources you use that we might be able to use as amateur weather enthusiasts?


We’re not weather forecasters, but our communications team is constantly putting satellite imagery of the Earth’s weather on the NOAA Satellite and Information Service website www.nesdis.noaa.gov and on social media (follow NOAA Satellites on Facebook and Twitter!). You can also get great views of weather at:

NOAA View: https://www.nnvl.noaa.gov/view/globaldata.html

Cooperative Institute for Research in the Atmosphere: http://rammb.cira.colostate.edu/ramsdis/online/index.asp

Cooperative Institute for Meteorological Satellite Studies Blog: http://cimss.ssec.wisc.edu/goes/blog/

MetEd: https://www.meted.ucar.edu/index.php

-- Tom

What is the most important component/system on the satellite with respect to data collection that you cannot afford to get wrong?

And what is the easiest thing to get wrong on these kinds of satellites?


Everything is important or else it would not be there, but to me the microwave data is the most important due to its ability to see though and below the clouds down to the earth’s surface providing us atmospheric temperature and humidity profiles important to the NOAA NWS long range weather models. Getting a good ride from the launch vehicle is very mission critical and the power system needs to last for at least 7 years. --Tom

What area will JPSS-1 image?


The whole globe! One of the reasons JPSS-1 is so important for the longer-term forecast is that it will view developing weather all across Earth that will show us what might be coming our way. As you may know, a dust storm off the coast of Africa, for example, can create a storm off the East coast of the U.S. JPSS-1 will circle the globe from pole-to-pole 14 times a day, imaging the entire Earth at least twice daily, from 512 miles above the surface.

JPSS-1 is particularly crucial for forecasting in Alaska and the Arctic, because other satellites can’t “see” as well in that region. Near the poles, the satellite actually provides more continuous monitoring---14 observations a day. Polar weather has a significant impact on weather in the middle latitudes, including the U.S., Europe, Argentina, etc.


How does JPSS-1 differ from Goes-16/r in terms of data collection? I assume, that Goes-16 is more towards photography on different spectrums and levels, how can one imagine the way data gets collected with JPSS-1?


Good question! From its fixed location 22,400 miles above the equator, GOES-16 produces a “snapshot” of the Western Hemisphere every 15 minutes, an image of the continental United States every 5 minutes and an image of a specific area as often as 1 minute to 30-seconds. This imagery helps meteorologists watch weather as it unfolds.

The polar-orbiting JPSS-1 has an imager too, but its most critical instruments collect atmospheric temperature and moisture profiles that get incorporated into numerical weather models. These models generate the weather forecasts you look at every day, as well as forecasts up to 7 days out, which are critical for preparing for extreme weather events. For example, on September 5, 2017, the forecast for September 10 at 8 AM showed IRMA off Key West - which was spot on, This degree of accuracy allows emergency managers and the public to prepare for extreme weather with adequate time.
Also differentiating JPSS-1 from GOES-16 are the infrared and microwave sounders, which collect data from different levels of the atmosphere. JPSS-1’s microwave sounder can see through clouds -- it can observe the warm core temperature of a hurricane and detect precipitation. GOES-16 cannot. JPSS-1’s imager also has a unique channel which allows visible images using moonlight. This is very effective for monitoring ice during the Arctic winter and fires at night.

-- Mitch

What is the moment in the launch and deployment process where you both individually give a sigh of relief?

Thank you both for doing this AMA! Your work is valuable and should be highly appreciated!


For me, there are two moments in the launch process when I give a sigh of relief. The first is when the JPSS-1 solar array deploys. When the solar array deploys and unfolds we are receiving energy from the sun to fuel the batteries on the satellite and at this point we are power positive. The second critical period happens about 54 days after launch. The cooler doors for the CrIS and VIIRS instruments open and allow the infrared detectors to get down to the proper cold operating temperatures. -Tom

What CPU is JPSS-1 using? Will there be any transmissions available to hobbyists (such as APT)?


Actually, JPSS-1 is using redundant Spacecraft Control Processors based on RAD750 single board computer processors. There is no Automatic Picture Transmission capability from JPSS-1, but there is a High Rate Data Broadcast (HRD) using X-band at 15 Mbps. --Tom

Hi!! There will be some API or somthing else that the developers/amateur weather enthusiasts could work or download images quickly?


The best place to go to download images quickly is the Imagery and Data page on NOAA Satellite and Information Service website at https://www.nesdis.noaa.gov/content/imagery-and-data

To see imagery of Alaska region, check out Geographic Information Network of Alaska’s (GINA) “Puffin Feeder” website at http://feeder.gina.alaska.edu

-- Mitch

Hello, and thank you for doing this AMA!

How much was your team involved in the design of the satellite? And how do you choose the exact orbit you want it to reach?

Apart from that, what instruments are onboard? What's their use?


In terms of the design of the satellite---NOAA provides the requirements for the observations needed for our NOAA products and services, for example weather forecasting. The JPSS Program then works with Industry to develop the technology to meet those requirements. We work hand in hand with NASA, who are the experts in satellite and launch services acquisitions, to make sure that satellites like JPSS-1 meet our requirements.

On the orbit---Since 1979 NOAA has always used polar satellite observations from morning and afternoon orbits. Two orbits are important because forecast models run every 6 hours and require global data coverage. In other words, global coverage is needed every 6 hours. With one satellite global coverage is provided every 12 hours. In 2006, NOAA and EUMETSAT, the European Meteorological Satellite agency formed a partnership, where EUMETSAT provides the morning orbit and NOAA provides the afternoon. The early afternoon orbit is particularly good because we get maximum solar illumination (for ozone and vegetation) and is also a time period where we see severe weather developing most often.

For a video about JPSS-1 that offers more information about polar orbits, see https://youtu.be/yc9MlQGGt1Q


I'm finishing a geography degree. Do you have advice on how to obtain a job in the market? I am very interested in gis.


I know that more GIS systems and associated data are being used by local county governments and I expect that use of GIS and satellite data will continue to expand in the years ahead as will demand for people that can use GIS. Consider adding some remote sensing education to your degree. --Tom

Can you speak about the actual launch process? Whose rocket is used? Are NOAA scientists involved in the launch process, or do you just watch and hope it works out? Once its launched, is NOAA involved in the deployment from the rocket into orbit, or is that something handled by the rocket owner/operator?


Hah, your question made me laugh, we rarely sit back and watch as we are always busy. This will be the 99th successful launch of a Delta II rocket that is being provided by United Launch Alliance under contract to NASA Kennedy Space Center (launching from Vandenberg Air Force base in California). The Delta II will use 9 “solids” (boosters) that provide an additional 1.3 million pounds of thrust. The first stage has approximately 10,000 gallons of rocket propellant fuel. The JPSS-1 separates from the Delta II within the first hour after launch.

The satellite supplier Ball Aerospace and Technologies Corporation and the NASA Mission Operations Support Team work side by side in the initial weeks after launch to perform all the detailed activities required to check out NOAA-20 (what JPSS1 will be called when it reaches orbit) and activate all of the subsystems and instruments. NOAA-20 should be ready for handover to NOAA for 24/7 operations approximately 90 days after launch.


How much of an impact on global warming studies is thus satellite projected to have and when will that data be made public?


Since we are global and the JPSS series will provide global observations well into the late 2030’s we will have the observations needed for a variety of applications, including weather forecasting, ocean/coastal ecosystems, and long-term changes of our planet. Data availability to the public will range from approximately 90 days after launch to about 1 year. The instrument data which is referred to as Sensor Data Records (SDRs) generally will be available roughly 90 days after launch, while the derived products called Environmental Data Records (EDRs) require more validation time. -Mitch

What are some lessons learned from SNPP that have been applied to the JPSS program? Satellite hardware, software, science algorithms, etc...

Assuming my orbit information is correct. What benefits do you predict there will be by having JPSS-1 be half an orbit (~52 minutes) behind SNPP? Do you expect to put JPSS-2 half an orbit behind JPSS-1 as well?

When will the data from JPSS-1 be considered operational?

edit: Added last question


There are gradual improvements like changes to more reliable components and some operational lessons learned. Each instrument has had to deal with some degree of lessons learned and some parts no longer being available. Europe’s MetOp-A+B (EUMETSAT) demonstrated the benefits of being 50 minutes apart and NOAA-20 will be approximately 50 minutes ahead of SNPP. JPSS-1 will be deorbited into the ocean at the end of its life so this is a new propulsion system requirement that the previous NOAA Polar Orbiting Operational Environmental satellites cannot do. This is part of an effort to limit space debris. --Tom

Hi, Thanks for doing this AMA. What is the difference between JPSS-1 and Soumi NPP https://en.wikipedia.org/wiki/Suomi_NPP, or JPSS-0, launched October 28, 2011. Thanks.


The NOAA-NASA Suomi NPP satellite was originally a research mission, built by NASA. It was so successful that NOAA pressed it into service as our primary operational polar-orbiting weather satellite. Suomi NPP has served as a bridge between NOAA-19 and JPSS-1, which will become NOAA-20, and has helped us get ready for JPSS-1.

The primary instruments aboard JPSS-1 are the same as those on Suomi-NPP, but there have been some design improvements which have resulted in an expected 7 year life compared to a 5 year design life for Suomi NPP. Some other improvements include improved reaction wheels that provide low spacecraft jitter disturbances, more modern and more efficient cells on the solar array, and additional blanketing on the spacecraft to protect it from orbital debris.


If you had to make a time capsule to send up with the satellite, what would you put in it and why?


A history of the NOAA-NASA satellites and their contributions to humanity--helping to save lives and property every day--would be my pick. It’s something I’m really proud of.

While we don’t have a time capsule aboard, there is a memorial plaque recently installed on JPSS-1 providing the names of several people that are no longer with us that worked on the satellite. Some members of their families are also planning to attend the launch. I had the pleasure of working with some of these people. --Tom

What do you consider the most acacurate way to measure temperature


One of the most accurate ways to measure atmospheric temperature is to use the instruments attached to weather balloons. Doing so provides direct measurements of the ambient air temperature as the balloon ascends. The problem is that the global coverage of weather balloons is quite poor, especially over remote regions such as the open ocean and the Arctic. Effective temperature observations require contiguous observations so we can not only observe temperature at discrete locations, but also the temperature gradient. So for that we have to use satellites with instruments that provide contiguous coverage. Temperature /moisture gradients drive the development of severe weather, and are provided by JPSS. Also, balloons have a tendency to break when they travel high into the atmosphere (above 70,000 feet). Satellites are much more durable.

-- Mitch

Hi Mitch,

Can you explain a bit about how the sounding devices are able to read temperature at so many layers of the atmosphere? How do you tell the difference between IR radiance from the ground vs. a cloud? How do you get everything in between?


Our instruments measure outgoing radiation at different wavelengths. Different wavelengths will detect radiation at different layers due to the behavior of atmospheric molecules which is a function of wavelength. Because radiation can be linked to temperature, we can tell the difference between the cloud and the ground. In the tropics this is easy - if the temperature is too cold it definitely is a cloud. For more information see http://www.ssec.wisc.edu/~baum/CloudPressure/CloudPressure.html.


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