Weather Satellite Imaging

[SV Someday Came]

I don't care -- I am soooooo stoked!! But.... I will control my enthusiasm to make a factual post. The attached images were imaged on my boat tonight. It is my first attempt. I caught NOAA 17 for about 11 minutes tonight. Closest pass was 499 miles. Say this is silly and not really about sailing. Say I don't know the theory. Say WhatEVer.

But using this software: WXtoImg: software to decode APT and WEFAX signals from weather satellites

And my mac laptop (and all running on DC power!!!)

And this receiver: Weather Satellite Station - Wettersatelliten NOAA Receiver and Antenna

And this antenna: http://www.cruisersforum.com/forums/...icture696.html

I imaged my first ever weather satellite image in real time at 0516 UTC Dec 18 2008. From MY boat. From a DC system I helped rewire. Using knowledge about amps and grounding I learned here!!!

Ayways, I have no life, so I am sharing my joy here. I have the complete set up documented in my albums on my profile.

Damn! I am excited!

BTW: The cross is where my boat is!!


Yippeeee!!!


Michael

[Christian Van H]

Two things; first THAT IS FREAKIN' COOL!, and second, the satellite sends down an image that has a map already imposed on it? HUH? I take it that these images were processed and uploaded to the satellite you downloaded from...

[Paul Elliott]

I hope Michael replies (and yes, this is way cool), but it looks like the WXtoIMG software can overlay a map on the received WXSAT image.

[SV Someday Came]

I don't know how the political boundaries were drawn. WYSIWIG. What you see is what I got. As the raw image comes in --- and it appears high resolution, like a very high resolution B&W photo, there are no political boundaries. As I am typing this, the computer is imaging NOAA 17 again. I will post the raw image.

The version of WXtoImg I use last is the free version. The next step up at 60USD does even more filtering and can create 3D images you can use special glasses with.

The program is (nearly) fully automatic. It will even auto-update Keplerian elements! The unprocessed image has a weird visual quality to it. But once the satellite passes and the signal is lost, the program goes to work (automatically) and starts running filters of gamma, contrast, and all sorts of Photoshoppian terms and you get some damn pretty images.

I sent the initial NOAA 17 image to Volker in Germany whose company (or maybe he is a clerk, I dont know) makes the APT-06 and he said the image was very good -- which means that I installed and shaped the antenna correctly. Maybe he was just humoring me.

I have included the image that came in during this post.

The first image shows both channels. That is the raw image -- channel A and B.

The image to the right is a "MSA Multispectral Analysis" "MSA Multispectral analysis (NOAA-# 2-4) Multispectral analysis. Uses a NOAA channel 2-4 image and determines which regions are most likely to be cloud, land, or sea based on an analysis of the two images."

The image directly below the raw dual image is a "MCIR map color IR" image. "MCIR map colour IR (NOAA) Colours the NOAA sensor 4 IR image using a map to colour the sea blue and land green. High clouds appear white, lower clouds gray or land/sea coloured, clouds generally appear lighter, but distinguishing between land/sea and low cloud may be difficult. Darker colours indicate warmer regions.

To the right is the "Daylight Sea Surface Temp" image. "Daylight sea surface temp (NOAA) Creates a false colour image from NOAA APT images based on sea surface temperature. Uses the sea surface temperature derived from just the sensor 4 image to colour the image. This is less accurate than the sea surface temperature derived from sensor 3-4 sea enhancement, but is available when the 3-4 image is not available. No attempt is made to distinguish cloud or land from sea. The sea surface temperature may be incorrect due to the presence of thin or small clouds in the pixel evaluated, or from noise in the signal."

The final image is a "NO colour IR enhancement (GOES/NOAA) NOAA colour IR contrast enhancement option. Greatly increases contrast in the darker
land/sea regions and colours the cold cloud tops. Allows fine detail in land and sea to be seen and provides a very readable indication of cloud top temperatures. This enhancement option is temperature normalised" That image is from NOAA 15


There are so many different filters and combinations of channels you can do with the software -- infrared, sea temp, veg temp, contrast, multispectral analysis, false color enhancement and more. And all this is just on the free version!

Anyways, mods, I won't post anymore images here -- I suspect I may be violating bandwidth rules. And I get this sense that I am a little afield of sailing! But.... the path led here for me.



Michael

[bene505]

This is really great. How much does the whole setup cost if you already have a laptop?

[SV Someday Came]

Originally Posted by bene505

This is really great. How much does the whole setup cost if you already have a laptop?

Costs can be minimal. First, you can build the antenna. There are several links to PDF docs on the net that can help you. Antena QHA para satélites polares. (30STV) is one link. That actually shows you the wiring inside the antenna. If you buy an antenna, the costs will range from about 180USD from National RF to about 300USD to a maufacturer in New Zealand. But alot of folks do make their own.

The receiver can be anything from a scanner to a dedicated receiver. Craig at WXtoImg has a list of hardware: WXtoImg: software to decode APT and WEFAX signals from weather satellites.

The software is free. What I posted above was imaged with free software. But this AM I upgraded and corresponded with Craig and the upgraded software is even more amazing. I constructed 3d images and the upgrade added access to more of the satellite's sensors and added alot of photoshop type commands. And I now can make composite images of multiple satellites effectively giving me a much larger image of the earth's surface. And I can make movies.

My set up was 180 for antenna, 270 for the receiver, 15 for odds and ends from Radio Shack. And I have read of people doing it much less -- the key is in doing your own antenna. Bob at National RF makes his elements from stainless steel and the plans on the net usually call for copper tubing. But I have bent copper tubing before, and if ever there was an antenna that is sensitive to inner and outer radii of its elements, it seems to be this puppy


There is a lot of information on the net and Craig's site is a good jumping off spot.

Michael

[Pelagic]

That is great Michael and what could be more pertinent to a sailor than weather monitoring!

In the past on Superyachts, I have been spoiled with HSD on Satcom to download weather, but now with my own saiboat, things will change.

For those using various systems like Grib files and ???, what do you think about Michael’s solution?

[SV Someday Came]

When I was growing up I wanted the stars more than a fist full of diamonds; I wanted them so bad it ached -- constantly. And to know I can do this somehow gives me a little taste of the heavens!

[Sandero]

Michael,

How often are these images updated?

Does the software have the ability to zoom in for a close look than continent size?

Have you done animation to show how things are moving?

[SV Someday Came]

Originally Posted by defjef

Michael,

How often are these images updated?

Does the software have the ability to zoom in for a close look than continent size?

Have you done animation to show how things are moving?

These images are not updated -- you just get new ones. Everytime an NOAA satellite -- or the Russian Meteor series -- pass overhead as along as they are transmitting on a frequency the APT 06 can receive, you get new images. Those were real time images I posted. Using a program like MacDoppler tracks all the satellites for me. Some of the NOAA sats broadcast all the time, others are off. This is all very new to me still, so I am not the best source of info. There is an awful lot going on upstairs. Right now, I am tracking NOAA 12, 14, 15, 16, 17, and 18. And so far, I have been able to image 15, 17, and 18. NOAA 17 is due in 2 hrs and the software is tracking and waiting to lock the signal and record. A good pass will give you 11+ minutes of telemetry. The quality of your image is clearly dependent on how the sat is and how long it is in view.

I am not good at explaining this, but depending on where you are on the planet will depends on how high a satellite will be in the sky. Since the orbits change, sometimes a pass will only be a few minutes and the satellite will only raise a few degrees above the horizon. That is why I like MacDoppler -- it gives good information on max elevation for my location, and it gives a nice visual "event horizon" for each satellite. But you really do not need MacDopper with WXtoImg, since the program automatically tracks like 50 bazzilion satellites and updates all the orbital variations (Keplerian elements) via CelesTrak. The images I posted were from NOAA 17 -- I think it was about 60 degrees elevation and was in view for about 12 mins.


I zoomed in on my location, but that was pretty useless. It was NOT like Google Earth (LOL!). You can enlarge and zoom images, but so I have not figured how to do so and maintain image integrity.

I have done one animation, but it does not seem right. I have made some adjustments to the software for RGB encoding, so I am going to see what happens when NOAA 17 comes into view.

[SV Someday Came]

Originally Posted by Pelagic

That is great Michael and what could be more pertinent to a sailor than weather monitoring!

In the past on Superyachts, I have been spoiled with HSD on Satcom to download weather, but now with my own saiboat, things will change.

For those using various systems like Grib files and ???, what do you think about Michael’s solution?

Supposedly, I can receive WEFAX as well, and I think image maps with Grib data -- but I have not figured that out yet.

[SV Someday Came]

These are my first Multispectral Analysis composite images using NOAA 18 and 17 on multiple passes. Max range is about 2100 nautical miles SSW from my X. Due west from me is about 1750NM. X marks where my boat is.

Second image is using NOAA 17. I did that composite on the Dec 22. The image is lighter than the first bcause of using more infrared (IR -- Ch B) to help build the image. Max nautical mile distance on the MC-IR image is about 2200NM.

I think Hawaii is just forever out of reach for me -- couple hundred more miles and the islands would show up!

Michael

[SV Someday Came]

I caught NOAA 15 tonight. I could not figure out why the image was "messed up" -- half was dark and half was light. I ran all sorts of filters through the images and nothing made sense.

Till I realized I was looking at twilight between night and day.

Here is only channel A (visible) from NOAA 15. No enhancement. Just visible light. Second image is the same with a map overlay.



Michael

[SV Someday Came]

Testing how an anaglyph satellite image looks on the net. The cloud structure is very detailed on the laptop -- but I am wondering if posted the intricate detail is still visible.


If you have some cheap 3d glasses please look and tell me if you can see any cloud structure.

[SV Someday Came]

NOAA 17 10:30AM PST
Really cool and unusual cloud formations off the coast of Baja.

Added an Anaglyph shot cause there are some weird cloud streaks about 200 miles off the coast of Northern California.... You will need your cheesy blue and red 3D glasses to see the Anaglyph image.