Extending USB 3 to Your Imaging Platform, Back to Lac qui Parle, and Amazon Vine Reviewing

I have only the vaguest sense of how USB 2 and 3 differ, but I do know how upgrades can mess up things you have running smoothly. Between mosquitoes and equipment upgrades here is what my relationship with USB has been...

The Shaky Start

In my pre-CCD days I imaged with a DSLR and used PHD for guiding via USB 2 (remember Shoestring Canon-to-USB cables?). The USB 2 sockets on my laptop were so poor that losing connection was a frequent occurrence. Getting Com port numbers sorted was not fun, and I had serious doubts about the technology. 

USB 2: True Love at Last

Everything became USB 2: Mount, imaging camera, guide camera, and eventually electronic focuser. The old laptop was replaced with a new one that had better connection hardware and it all worked wonderfully together. After the 2019 Nebraska Star Party I purchased a portable screened shelter to keep away the bugs, the plan being to use one of the ubiquitous USB 2-over-Ethernet extenders to pass from the shelter to the imaging platform, and it worked. Happiness and bliss were mine!

Coleman 10x10 Skylodge Shelter. It's also useful at night.

Upgrading Woes

Time doesn't stand still; things change. In my case I upgraded imager, guider, and focuser; they all became USB 3. And surprise! The USB 2 extender would no longer be adequate. 

I needed to reach about 15 feet from the shelter to the imaging platform. A USB 3 cable that long is well beyond the suggested length limit, so I needed another solution. There wasn't much to choose from: expensive wireless hubs (ASI Air+ and beyond), DIY-ing together a minicomputer and wifi unit, or a USB 3-over-Ethernet extender hardware solution. I didn't care to spend the $300 or more for wifi and I really didn't want to wade into the issues around adding a minicomputer. And I could not find an Ethernet extender for USB 3. But there was another option...

Active USB 3 Cables to the rescue

Active USB 3 cables use signal amplification to provide greater cable lengths, with the determination of "greater" left to the cable maker. The performance of these seems to be something of a mixed bag. Some people have reported that active cables don't play well with the gear I have from Pegasus and ASI, but I suspect that comes from not supplying power at the imaging (female) end of the cable. The one I bought is 16 feet long, and provides the option for a power input at the imaging end of the cable. 

Active USB 3 cable

The power input posed a wrinkle. Like most active cables the input uses 5V input through a 3.5x1.35mm plug. The source for this power is usually an AC adapter of some sort. This isn't handy in the field unless you have AC--which will not be the case for me. 

My power box is all 12V automotive sockets or Anderson Powerpole connectors, so there's no built-in 5V output. The solution was to use an old 12VDC USB device charger that I had lying around. It's designed to plug into the same automotive sockets that I have on my battery box. Because the charger and active cable combined uses maybe one watt it won't affect my battery's energy budget much at all.

Typical Automotive plug USB charger

What I didn't have is a USB 2 power cable with a 3.5x1.35 plug on it, but Amazon had that, too.

The short cable between charger and active cable

The end of the active cable can be strapped to a tripod leg and then a short USB3 cable runs from it up to my Pegasus Powerbox for distribution.

An indoor test of this with everything running under the guidance of NINA was perfect. The powered cable had no issues with any of my things, Pegasus electronic focuser, ASI 2600 CCD, or ASI120 guide camera. The mount was happy with the USB 2 carried on the cable, too. NINA collected 57 images, and downloaded them all plus continuous PHD2 frames without a single fault. A test under the stars is needed, though, since that will add guiding instructions to the data flow.

This is a timely fix for my upgrades, because at the end of July it's time to go

Back to Lac qui Parle

Yes, despite the storms of my first night there, I've reserved 3 more nights at Lac qui Parle near the end of July.

I can't decide on the imaging target for this jaunt. I should probably finish my Veil mosaic, but I'd rather do that from Eagle Lake. How about a two-panel mosaic of the Lagoon and Trifid Nebulae? Both transit around the time it gets sufficiently dark for imaging, so I can avoid the dreaded meridian flip and the minor glow of Montevideo in the southeast. Given the limited altitude of these targets it will be one one panel per night. 

Do you think I can get two clear nights out of three? Me neither.

Speaking of Amazon....

I've been a regular reviewer of the things we've purchased from Amazon and apparently that tripped their AI into thinking I should be a Vine reviewer. Vine reviewers are the ones who get their reviews tagged with "Vine Customer Review of Free Product." Basically we get products for free in exchange for a timely review. The catch is that the value of the product (as given by its possibly inflated retail price) is treated as taxable income. In my wimpy tax bracket this means almost everything I review is mine at a crazy large discount.

Thank goodness Vine allows me to choose what I will review. Most of the products offered on Vine are things that I probably would never need nor want. For example right now there are 75,468 items available for review. An awful lot of them are odd-looking cases for cell phone models I don't own, silicone ice cube molds, and other things of doubtful value, so a wise reviewer must hunt a little. 

It also helps to not play Amazon's game of trying to be a Gold Tier Vine Reviewer. The gold tier requires one to make a lot of reviews in exchange for being offered items over $100 in value. As one Redditor commented, his obsession with maintaining gold tier status was filling his house with shipping boxes and the stuff that came in them. I'm quite happy to remain a peasant in the silver tier. Actually, if there was a tin tier I'd be cozier in that.

But Vine can be useful because every now and then something of interest gets listed, and if you can grab it before someone else it's yours.

My lust for lithium is leading me to glom onto small LiFePo4 batteries that are great for camping. I've now collected four batteries, and will probably add more. A couple of them will be dedicated to augmenting my laptop's battery. Another will power my camp fan for those hot, breathless days and nights. Depending on how many more of these I score I may bring some up to Northern Nights Star Fest as swap meet fodder. Oops, no. Vine rules say that items must remain mine for six months.

Another Vine offering I may use for astronomy is one of their large table covers. These are waterproof, silvered on one side, and have tie-downs. Does that sound like a tarp for covering an imaging platform? It sure does and for a cost to me of about $10. I'll let you know how it works out.

Table cover fabric (note silver interior lining)

Table cover black side out in conventional use

Getting Out of Town, but to Where?

This post is going to be an exercise in overthinking a simple task like combining imaging and camping, much like the many posts I've made about batteries and such. Wander in at your own risk. 

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Last time I said this post would be about some parks I visited in the hope of finding a nice dark place at which to image and camp. Here are the results of that little jaunt and the realization it forced upon me. 

• Cedar Hanson County Park near Trimont: Very nice for campers, but too many trees
• Sands Country Cove campground southwest of St. James: High density, packed even in April, which is not the nicest month to tour Minnesota. Reservations will be tight, just like how it packs the RVs together. It looks like it caters to families with big RVs. On the other hand, no trees.
• Eagle's Nest County Park east of St. James: Needs a variance to park away from trees in an open pasture that's probably dedicated to horse riders. I've written to the county parks person about that variance, but this is a "light green" light pollution area so not much darker than a local site.
• Voss Park, Butterfield: A large area of trees was removed and sites added since my last visit. It's also not much darker than a non-camping site I use now.
• Lake Hanska County Park, north of La Salle: Too many trees.

Yes, that's correct, none of these were suitable.

Related: An article by the Dyrt.com reports on a poll of 7000 campers. One result was

"In 2023, 45.5% of campers reported difficulty booking a site because a campground was sold out. It was four-times harder to find an available campsite to book than it was in 2019, when just 10.6% of campers reported difficulty."

Here is the realization: Campground reservations are a necessity. Sure, some campgrounds say they are first-come, first-serve. Theoretically you can see a good forecast in the morning, hop in the car and drive three hours to one of those campgrounds hoping there's an available spot for the night. But the chances are that spot will be gone by the time you get there, meaning you have to turn around and drive three hours back home. Not good. Minnesota state parks do allow same-day reservations, but your chance of that working in your favor seems particularly small if you want more than one consecutive night.

 

The problem with advance reservations is the same as that with multi-day star parties: the weather. You can't know what you're going to get.  But unlike star parties with registration fees and associated travel expenses, camping reservations do give you an out. You can cancel the reservation and get some (or most) of your money back, and then complain about the clouds from the comfort of your own home.

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The Hunt for Darkness

Let's say you enjoy camping and want to combine that with dark-sky imaging as an alternative to attending distant star parties.

Choosing when to camp is easy, just mesh your personal schedule with any time the moon isn't a bother. Then match that to campground availability. 

Deciding Where to camp is a little tougher. If you live in a light-polluted city you'll probably need to drive one to three hours to find dark sky.  That means you should think about what your daily safe driving range is. That's the amount of time you can stay alert and your back won't punish you the next day. For me, old and decrepit as I am, that range is about six hours. For the rest of this post I'll assume a driving range of half that -- three hours -- because that permits turning around and returning home if a crucial item was forgotten ("OMG I forgot the counterweight!"). 

With your driving range decided you can start your hunt for campsites that are reasonably dark, accept reservations, and have open sky. And I do mean hunt because campgrounds satisfying all three conditions seem to be rather rare. Some camp sites may be dark enough overhead but have troublesome horizon light domes from nearby cities in the direction you want to image. Many camps are full of shade trees that block the sky. Some like to maximize land usage by packing large RVs so tightly together that they obstruct the sky. Some are near major highways and almost impossible to book. Some are rather primitive. Will you need power and water? Flush toilets? A shower? Everyone has a particular set of requirements.  If you need to run a generator after 10 P.M. you may have issues with a campground's quiet time. And some smaller parks are just sort of unkempt or creepy, making you wonder if they're a "party park" for locals (see for example, Pine Ridge Park north of Herman). Your hunt is for a camp where you can securely image and enjoy yourself while doing so.

It's almost May now and places are taking reservations: it's time to get site hunting. For this post I used Google search, Google Earth, Google Maps, and Light Pollution Atlas 2006 (selecting the 2022 overlay). Google Earth showed me if the locations are infested with trees, Google Maps provided directions and drive times, and the Light Pollution Atlas was great for figuring out how dark a site is and what the horizon situation might be.

Other online resources that were helpful included Minnesota's state park finder and a map of Minnesota's counties. Googling a county name will point you to the county's home page, and from there you can see what it has for parks. A few counties structure their web sites as if they don't want anyone to know they have parks, so be ready to dig.

There are a lot of campground finders on the internet, two that seemed useful are Hipcamp for smaller private camps and The Dyrt for pretty much everything else.

My personal site hunt was limited to the south and west of the Twin Cities because I enjoy that part of the state and it's less tree-infested than elsewhere. You're free to hunt wherever you want. But first we should think about just how dark we want it to be.

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What is Dark Enough, and What is Too Dark?

I know, I know, there's no such thing as "too dark."  But there can be a dark so dark that it can't be reached within your driving time limit.

My very subjective take on "dark enough" is based mainly on my past imaging at different sites. 

First a bit of terminology: the Light Pollution Ratio, or LPR. LPR is the ratio of light pollution to natural sky brightness; an LPR of 1.0 means that the light pollution is equal to the natural sky brightness. The smaller the LPR the darker the sky. (The Light Pollution Atlas gives you the LPR when you click on its map.)

The diagram below shows an LPR diagram from the Light Pollution Atlas 2022 overlay. The area covered is from near the South Dakota border at left to a bit past Eau Claire WI at right, and just south of Duluth at top to Albert Lea at bottom. Color indicates LPR value with light green being between 0.6 and 1.0; dark green is 0.33 to 0.6. I've changed all areas with LPR greater than 3 to black.

Light pollution map of southern Minnesota. Click to enlarge! 

My back yard has an LPR of 24.5 (!), which is emphatically awful. If I want to image emission nebulae it's narrowband filter time. LRGB imaging (my preference) works well from Eagle Lake (LPR 2.34, EL on the diagram) and Starhome (a friend's back yard, LPR 2.9, SH on the diagram). They're both on the fringe of the Metro and suffer from its huge light dome. Cherry Grove (LPR 1.08, CG on the diagram) is located south of the cities and is very good overhead but less so northward and to the southeast. A person I corresponded with during my Astronomical League Bright Nebula imaging years was using LRGB from a Missouri site with an LPR of 0.6 and his images were nothing less than excellent. I've also imaged from locations where the LPR is under 0.2 and can attest to their excellence.

My take is that an LPR > 7 or so will push you to use narrowband or at least multiband filters. An LPR < 7 is probably dark enough for LRGB imaging of most targets, and an LPR < 0.6 is great for almost any DSO. If you're planning to go super deep, like imaging IFN, then you probably want it as dark as possible to reduce your total exposure time.

My hunting goal will be to find locations where the LPR is 0.6 or less; my motto will be "Go Dark Green or Stay Home." You may be willing to accept something brighter, or demand even darker based on your imaging gear and targets.

Once I determined my personal "dark enough" I could perform my hunt. What follows is the result. See the summary at the end of this post for campground LPR values, links to the individual parks/campgrounds, and other comments.

Minnesota State Parks

Minnesota state parks are widely regarded as some of the nicest in the country. The facilities are well maintained and staffed by knowledgeable outdoor enthusiasts. And lucky for us there are two parks that may be particularly suitable for imagers!

Not suitable -- either too bright or blocked sky: Big Stone Lake, Blue Mounds, Camden, Flandrau, Fort Ridgely, Glacial Lakes, Kilen Woods (probably), Lake Maria, Minneopa, Minnesota Valley, Monson Lake, Myre Big Island, Sakatah Lake, Sibley, Split Rock Creek

 

Suitable: Lac qui Parle and Lake Shetek.

Lac qui Parle is a little darker than Lake Shetek but Montevideo to the southeast maye put up a light dome. One person who has been there said he did not note any problem with the horizon. The positions of these parks are indicated on the diagram above. Both parks can be found in its lower left corner.

All state parks require reservations.

Minnesota County Parks

County parks operate on generally lower budgets and their facilities vary widely. Even so, they will likely be packed full of campers during summer. An additional factor for these parks are monthly and seasonal campers who will fill spaces semi-permanently. A brief look at County parks shows a few promising locations:

Jackson County: Sandy Point (reservation required, choose site carefully to avoid trees, needs a visit to verify horizons)  

Murray County: Sundquist, Lime, and Swenson (no reservations)

Lincoln County: Picnic Point  and Norwegian Creek (reservations required)

Lyon County: Twin Lakes (reservations required)

Yellow Medicine County: Timm Park. Needs a visit to see which if any sites are suitable. (reservations required)

Counties that have no suitable county parks are Blue Earth, Brown, Chippewa, Cottonwood, Faribault, Freeborn, Kandiyohi, Martin, McLeod, Meeker, Mower, Nicollet, Nobles, Pipestone, Redwood, Renville, Rock, Sibley, Swift, Watonwan 

Minnesota City and Town Parks

Many small cities and towns have parks that offer camping. These are generally near the population center and so will have considerable light pollution. I found none that were satisfactory for imaging. 

Private Campgrounds

I am omitting campgrounds that pack RVs tight together; giant RVs are as opaque as trees. 

All of the following locations need to be visited to assess their suitability.

Camping on Private Lake. This was found on Hipcamp. It has an LPR of only 0.3! You would need to talk to the owner about being able to set up away from the trees. If you don't need AC power siting might be easier. Reservations required.

Camp Summit in Hadley. Seven sites, accepts reservations, but also allows space-available. LPR = 0.45

Talking Waters in Gary, SD. Many sites, requires reservations. LPR = 0.51

Niemackl Lake near Herman, MN. Accepts reservations by phone. LPR = 0.26. I visited this a few years ago and found maybe 3 or four of the 10 sites were decent. Neimackl has the distinction of being the darkest campground in my survey!

There are a few places in northern Iowa that look very good, but they are generally about 3 hours distant and will be very busy.

There are probably other suitable private campgrounds. If you know of some please let me know.

Summary: The Too-Short List of Suitable Campgrounds In SW Minnesota

This omits campgrounds that need a visit to judge suitability. (Trees look bigger in person than on Google Earth!) 

Reservations required:

Lake Shetek S.P., LPR = 0.52, use only the Sunrise Campground

Lac qui Parle S.P., LPR = 0.37, use only the Upper Campground

Twin Lakes C.P., LPR = 0.43, only north portion can be reserved at this time

Picnic Point C.P., LPR = 0.42

Norwegian Creek C.P., LPR  = 0.51

Reservations not accepted:

Sundquist C.P. , LPR = 0.35

Lime C.P., LPR = 0.43

Swenson C.P., LPR = 0.41

If you have experience imaging at these or others, let me know how you liked the location!