Perimeter Walk


New Field Map

Wednesday Hope and I took a long walk. According to the GPS unit, below, she walked 12 kilometers and I walked 29 kilometers. The ratio fits as she had cut across back to the house at about the half way point. This is a very long hike for the short legs of a six year old and I was amazed that she stuck with it so long. It was handy that we were walking a large circle so she could cut a cord when she got tired.

29 kilometers! Holly-Kowa-Bunga! That is a long ways, you say! It is. That isn’t 29 kilometers in a straight line but the total motion as the GPS measures it. I also have some concerns as to the GPS’s accuracy as I’ll discuss below. It seems that when measuring distance walked the GPS unit literally measures steps like a pedometer. I’ve not read the manual in detail but this fits with what I’ve seen when walking in straight lines. Even then the exactness is questionable. Still, it was a long ways.

Key: Pink zone is our old pasture area of our farm.
Red line is part of our land boundary.
Sugar Mountain is on the right of the image.
Sugar shack is at its base by the road.
Perimeter we walked is the connected black dots inside of the light area according to the GPS.
Light area is my estimate of real area of fields based on topo maps and ortho photos.

The perimeter is the outline of our new pastures. Except that the GPS waypoints ended up not correct according to my orthophotos or topo maps. One problem may be that different mappings distort the vertical slopes differently. We live on the side of a mountain and there is a lot more land on a hill than a flat land. The two yellow “Big Rocks” are visible in the orthophotos and easy to reference in the topo maps which is part of how I know the GPS is so far off from the other maps. There are also several small clearings, stone walls, tree lines, distinctive trees and logging trails that give clues to where the GPS should have matched but didn’t. So much for the GPS.


Garmin eTrex Venture HC GPS Unit

I had bought this GPS last year to use for mapping in our forestry work. Am I expecting too much from the GPS? It was advertised by Garmin as being high accuracy. I have a very old GPS from the mid-1990’s that was accurate to about two feet. The Garmin eTrex Venture HC claims on the display at various times that it is accurate to 3 meters (1 meter is about 3′), 6 meters, 8 meters, etc. That is awful. My old one was far better.

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GPS Around Old Farm House – Error Map Test

This is a map showing the errors of the GPS. The top image is the measurements it gave around our old farm house foundation. The bottom image is the actual foundation which is square and 100′ long. I know because I put that foundation in. It is a neat, straight bond beam of steel reinforced concrete done by yours truly and measured many times before and since. The GPS gets the angles and measurements completely off. Sad.


View North Across Valley From South of Fields – Click for Large Size

I took this shot from the upper left of the map above near where the perimeter jogs in looking north across the fields across the valley towards Knox Mountain. You can see our cottage, the new butcher shop rising, our old farm house, the red dump truck, lower marshes and then Knox Mtn and Butterfield Mtn in the background. Click the photo for a large version with more details.

Since the clear cut for the fields was just completed last fall the pastures haven’t grown to grass yet. Soon they’ll be green with forages. It is amazing how quickly they’ll transform from forest back to pastures. Ben and Will have been seeding this week now that most of the snow is gone. As of today they’ve completed about 40 acres of spreading. Since our terrain is so steep and rough we have to do this all by hand – no use of a tractor seeder.

We marked many trees to keep during the logging process such as the big one there on the left as well as many line trees along stone walls. These will provide shade, soil stabilization and forage from nuts. The rotting stumps, decaying logs and regen will also be wonderful food for the pigs and sheep. The wildlife will also bloom with the opening of the fields – deep forest is not very bio-diverse. We’ll likely also see a bumper crop of berries up in the high pastures this year. I’m working on figuring out how to manage the harvest of pork vs berries with their alternative needs. Pigs are very good at culling the old canes – the berries just need about two years to come back afterwards.


Nuts on Big Rock

Speaking of nuts, here is one of the nuts that Hope found on the northern Big Rock. She planted it. Like the Mafia plant someone. Actually, she what said was she was giving it a burial, not like a squirrel burying a nut to store it for the winter but a burial as in last rites. It is interesting how each child is unique – and here I thought we were using a cookie cutter. This is a child that likes “Addams Family Values“, “Lord of the Rings“, “Harry Potter” and other spooky stories. Bears beware.


Bear Prints

Speaking of bears, here are bear prints in the snow up in the high pasture. It is a small black bear. We also saw rabbit, moose and deer droppings. I saw Kavi’s prints up on the top of the ridge along the back edge of the new pastures. He has large feet, much bigger than the coyote and fox tracks I saw further north earlier this winter.


Tiny Nest on Blackberry Cane

This is perhaps the smallest bird’s nest I have ever seen. It was on a bramble. It was about the diameter of my thumb and forefinger making a circle. Perhaps a humming bird? We have many of those around here. Ideas?


Hope on Big Rock North

This Big Rock is visible from space. Just kidding. Not from space but it is visible from the high flying airplanes that make the orthophotos I use in mapping our forests. I imagine it hollowed out and a home to gnomes or hobbits. It is great for climbing on. Hope is sitting on the uphill side which is just a bit taller than her. The downhill side, where she jumped, is about three times her height. She lived. Good thing it was a downhill roll on impact!

Outdoors: 33째F/18째F Sunny
Tiny Cottage: 65째F/61째F

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About Walter Jeffries

Tinker, Tailor...
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12 Responses to Perimeter Walk

  1. Ryan says:

    I heard once that GPS are not accurate so that terrorists could not use them.

    Our Garmin GPS is consistently off by 1/2 a city block to the east really painful in our curvy neighborhood of streets.

  2. Teresa says:

    What an absolutely wonderful walking tour. I can almost feel my legs getting tired as you describe all the wonderful sights. I must say I am relieved I don't see bear tracks in the snow here.

  3. Hello Walter and Family,
    Sounds like Hope had a great day at school!
    I am interested on what types of seeds you chose for Ben and Will to plant.
    We do not know much about the different grasses, other then watching how that animals respond to the hay we buy from different farms.
    Perhaps seed selection and sowing is worth its own post.
    Take care
    WBF

  4. Katie says:

    What is the light green area over by sugar mountain? is that more fields? I see your red line boundary but it seems to go a long ways. Just how big is your property?

  5. Anonymous says:

    Today in NYT:
    Push to Eat Local Food Is Hampered by Shortage

    Erica Zimmerman and her husband spent months pasture-raising pigs on their farm here, but when the time came to take them to slaughter, an overbooked facility canceled their appointment.
    http://www.nytimes.com/2010/03/28/us/28slaughter.html

  6. Ryan, how unfortunate. If this is the case the GPS makers should stop advertising them as "High Accuracy". Eight meters off is useless for mapping. *huge sigh*

    WBF, that is a good idea for a whole post. The seed mix I made up is a combination of grasses I know do well, several clovers, alfalfa, some grasses I want to test and a few more plants. I'll then watch how they do over the next few years so see which do well in our climate and soils as well as figuring out what the animals like. Last year I took a lot of plot photos looking down at the ground to record what we already had for plants.

    Katie, the light green on the right is the result of the 1998 ice storm. We lost about 150 acres of timber land to that storm including the top half of our sugar bush which is what you're seeing there. It was very hard listening to the trees fall for four days as they broke and toppled under the weight of the ice. Had I been able to cut that timber over a 30 to 50 year period it would have been over a million dollars in lumber. Life happens. The area is now filled with regen and berry bushes. In another few decades it will be forest again. The moose like the browse. Most of our land is timber, some is marshes and then there is the pasture area for the farm.

  7. Nanan says:

    I absolutely love that photo of the nest. It is so perfect! I was looking at the map at the top and trying to figure out how much fields you have. I think you had said the old fields were 20 acres. What is your new total. How many pigs and sheep will that support? You talk about your pigs a lot but I know you also have sheep. Will you get cattle? It looks like a lot of land. I think it is wonderful how you are keeping the land active in forest and in fields. I remember taking a bio class where the professor talked about how it is the edges where forest and grass lands come together that support the greatest numbers and variety of plants types.

  8. I'm not exactly sure how many acres it is because the GPS didn't get very good readings. Fortunately the exact number isn't important – it is definitely enough pasture to support the number of animals we plan and in time we'll do some of it as hay fields. The top area is very flat.

    Currently we don't actually have any sheep but I plan to get more and restart our herd. They co-graze very well with the pigs. Someday we would also like to get cattle and we've talked about goats. For this year our big focus is seeding the fields, fencing and building the butcher shop – our big project.

  9. I thought I might chime in with a thought about your GPS unit. I have found in my own GPS-use experience that motion – too fast or too slow – can affect the accuracy. So can the weather, the number of satellites you're connected to at any given time (i.e., tree cover affects your connection) as well as curves/bends in the trail. It's a bummer that your reading was off but I do wonder if the speed of the walking affected things. If you stop a lot and don't keep a steady pace, you're unlikely to get a solid reading. I don't fully understand all aspects of this technology, but I've done some GPS "drawing" with my kids (http://raisingmaine.mainetoday.com/blogentry.html?id=10221) and learned a few lessons from that smaller scale experiment re: accuracy. But steady speed, that's a key piece of things when looking for accuracy. I think it has to do with the earth being in constant motion and you needing to do the same with your unit to make everything agreeable. How's that for a scientific explanation? Not. ;)

  10. Interesting. Our speed was definitely not consistent. What I did do was stop at every waypoint for a full minute and hold the GPS unit level to try to let it get a good reading. I also picked a day with fairly clear skies – it was sunny blue skies when we started, light clouds later. We're up high and there were no trees since we were measuring on a new clear cut on top of a mountain ridge. I had hoped that would give accurate readings. I think Ryan may be onto something since my old GPS did so well but that was back before all the 9/11 nonsense. *sigh*

  11. Nick says:

    I remembered reading a while ago about how inaccurate your gps was and thought that it might be because of the altitude but probably the mountain. Here is a link that should explain what I’m trying to say. http://gpsinformation.net/main/altitude.htm so if you are still having problems with GPS accuracy you might want to try a GPS unit with a barometric altimeter. Obviously no promises but if you can borrow one from someone and try it out…..good luck.

    • Thanks, Nick. I have essentially given up on the GPS. During the 1990’s and early 2000’s I had a GPS from Delorme that connected to my laptop. It was extremely accurate. The modern GPS that I now have from Garmin which is advertised as high precision is awful. It is so bad I simply gave up on it. We have excellent reception with lots of strong satellite signals and we’re on top of cleared mountain fields with no obstructions. Yet the Garmin GPS gives bad numbers. After working with them and reading elsewhere on it I came to the conclusion that part of the problem is the government changed how the GPS signals work. After 9/11 they made GPS less accurate as a “homeland security” issue. Sad. It means that I can’t use it for mapping our farm and forests. I have to rely on old surveying techniques which give far better results than the modern technology.

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