Yellowknife – INSAR

Another satellite in our tool box is the Canadian designed and built Radarsat. Compared to most other satellites, it does not take pretty pictures. Instead, the Radarsat satellite fires a radar beam to earth at a specific wavelength, and the beam bounces off the surface of the earth and returns back the satellite. Differential Interferometric Synthetic Aperture Radar (D-InSAR) is a technique that uses repeat synthetic aperture radar (SAR) observations, separated in time, of the same area on the Earth’s surface to detect small movements of the ground surface. Since the satellite is moving in an along a fixed orbit at constant height above earth surface, the distance between the satellite and a specific point on the earth’s surface is a constant. With a repeat observation, millimeter-scale changes in the distance between the satellite and the earth’s surface can be calculated by comparing the phase shift of the wavelength of the radar signal that was fired by the satellite. A 3D model (digital elevation model) is used to remove the phase difference resulting from topography and the remaining phase difference is converted to vertical displacement which represents the displacement of the ground surface. Although this is a simplistic explanation of the process, a more detailed discussion of these processing steps may be found in Short et al. (2011).

InSAR

Using SAR data collected during the summer of 2010, scientists at the Canada Centre for Remote Sensing, the Geological Survey of Canada, along with their northern partners, used differential interferometry techniques to map ground surface displacement in the Yellowknife area. Figure XY shows the ground displacement derived using stacked RADARSAT-2 D-InSAR from May 23 to September 20, 2012. The results are categorized in terms of the relative amount of displacement rather than focussing on the absolute values (units are in meters). Areas shown in red and yellow, are undergoing low and moderate downward displacement (subsidence) in the range of -1 to -3 cm and -3 to -6 cm per season, respectively. Ground that is considered stable, where no vertical change was calculated is shaded in blue.  Areas where the displacement is upward, due to ground surface heave or vegetation growth of up to 6 cm, are shown in pink.  At some locations, labeled ‘Incoherent’ the vertical change is presumed to be significant and is beyond the measuring capabilities of the D-InSAR process.

 

The ground surface displacements shown on the map are considered to be seasonal since they occurred during the May to September time period. Areas of downward displacement may result from seasonal subsidence caused by thawing of the active layer (seasonally-frozen ground) or permafrost (perennially-frozen ground) or soil compaction. Upward surface displacement may result from ground surface heave or, under certain circumstances, vegetation growth. The latter represents an apparent upward displacement that is not the product of ground surface displacement. Both downward and upward ground surface displacements may be from natural and human-induced processes.

Verification of the results of the InSAR displacement in areas identified as having moderate seasonal surface subsidence. We observed and measured indications of subsidence such as undulating roadways, areas that were presumed or measured to have been levelled when constructed, and noted and measured cracks and rotated sidewalks.

 

Summary:

The purpose of this study is to present and interpret D-InSAR measurements of seasonal surface displacement over discontinuous permafrost terrain in Yellowknife. We conducted field verification to support the results observed by the InSAR process by documenting areas undergoing low and moderate downward displacement and noting the impacts on private property and municipal infrastructure. Mapping of surface displacement is important to assess ground and infrastructure stability, and to monitor mitigation in problem areas, and to plan future land use. Surface displacement may be from natural or human-induced processes that cause vertical movement of the ground. In Yellowknife, and other areas in northern Canada, surface displacement may be caused by freezing and thawing of the active layer (seasonally-frozen layer) or the permafrost (perennially-frozen ground). This presents challenges that increase the cost of constructing and maintaining infrastructure (e.g. roads and buildings), especially if the displacement continues in the same direction over an extended period of time. The knowledge of where the problem areas occur and the relative magnitude of displacement provides engineers and municipal planners with key information required to reduce the cost and risk of developing and maintaining northern infrastructure.

Reference:

Wolfe, S., Short, N., Morse, P., Olthof, I., Schwarz, S., Stevens, C. (2013). Application of RADARSAT-2 D-InSAR season surface displacement to municipal land use in discontinuous permafrost terrain, Yellowknife, Northwest Territories, Canada. fCorresponding author, . ** Note: this work is not yet published

 

Short, N., Brisco, B., Couture, N., Pollard, W., Murnaghan, K. and Budkewitsch, P. 2011. A comparison of TerraSAR-X, RADARSAT-2 and ALOS-PALSAR interferometry for monitoring permafrost environments, case study from Herschel Island, Canada. Remote Sensing of Environment, 115, 3491–3506, doi:10.1016/j.rse.2011.08.012.

 

 

 

Bullocks Bistro – Yellowknife’s Best Known Fish Restaurant

Bullocks Bistro, in Old Town Yellowknife serves up the best fish in town, and is often featured on CBC Arctic Air.  Can’t think of too many restaurants that actually let you, and encourage you to leave your mark on the ceilings and walls !.

SCH_3491 Panorama-2_TM-TB Click on the image to see it bigger.
To view a 360 degree animation of this scene, Click Here. This requires the QuickTime Player. Click the icon on the upper right corner of the animation to get a full view. Depending on network speed, the image may take a moment to load.

 

Camera gear: Nikon D700 and a Peleng 8mm lens on a custom monopole. Four pictures were combined to create the panorama images on this page.

Folk on the Rocks (FOTR)

 

Folk on the Rock (FOTR) started as a small gig in 1980, and has now considered to be one of Canada’s BEST music and cultural festivals.

Highlights include artists and musicians from across the north, across Canada and international all coming together for a weekend of musical and cultural magic on six separate stages. FOTR is held on the third weekend of July, in Yellowknife.

 

A split view of the Main Stage.

 

A view of the Cultural Stage. Click on the image for a larger view.

 

To view a 360 degree animation of this scene, Click Here. This requires the QuickTime Player. Click the icon on the upper right corner of the animation to get a full view. Depending on network speed, the image may take a moment to load.

“Little Planet” view of the Kids Stage. Click on the image for a larger view. Click ‘back’ on your browser to return to this page.
View a 360 degree animation of the Main Stage, Click Here.  Click the icon on the upper right corner of the animation to get a full view.

 

“Little Planet” view of the Main Stage. Click on the image for a larger view. Click ‘back’ on your browser to return to this page.

 

 

 

To view a 360 degree animation of “And the woman said” on Stage Left. Click Here This requires the QuickTime Player. Click the icon on the upper right corner of the animation to get a full view.

Everyone’s favorite place to be on a hot sunny day….The Beer Garden

To view the 360 degree animation of “Snake People” in the Beer Gargen . Click Here This requires the QuickTime Player. Click the icon on the upper right corner of the animation to get a full view.

To view the 360 degree animation of “Hot Vibrator” in the Beer Garden. Click Here This requires the QuickTime Player. Click the icon on the upper right corner of the animation to get a full view.

 

 

 

“Little Planet” view of the Beer Garden. Click on the image for a larger view. Click ‘back’ on your browser to return to this page.

 

 

 

 

Camera gear: Nikon D700 and Samyang/Bower 8mm on a monopole. Four pictures were combined to create the panorama images on this page.

Old Town Yellowknife – from MacEvoy Rock

To celebrate May Day (May 1st) and the coming of spring, I headed up MacEvoy Rock in Yellowknife’s Old Town. Of the two hills in Old Town, Pilot’s Monument is higher and far more popular that MacEvoy Rock. For creating panoramas and a quite place to hang out, MacEvoy Rock suits me perfectly.

In this image, downtown Yellowknife is directly under the sun on the right side of the image. Pilot’s Monument is in the middle of the photo, and Back Bay is on the far left.

Click on the image for a larger view.

 

Click ‘back’ on your browser to return to this page.

To view the 360 degree animation. Click Here This requires the QuickTime Player. Click the icon on the upper right corner of the animation to get a full view.

Compare to Panorama from July 12, 2011.

Camera gear: Nikon D700 and Nikon 20mm/2.8 lens on a monopole. 12 pictures were combined to create the panorama images.

In-Action Photography*

As photographers we are on the sidelines using our cameras to capture the moment and capture the action. As an active person, naturally, we want to participate in sport activities.

However, in my experience, cameras and active sports do not seem to go together very well. I been frustrated with cameras since they were not designed for active participation in sport activities. Large SLR’s require two hands to operate, and most point-n-shoot cameras didn’t have suitable image quality. Neither camera types are rugged and waterproof. Actually, during the past 20 years, I have destroyed (and drowned) a few cameras trying to combine sport and photographing the action.

Until now.

In August 2011 I bought a GoPro camera. It is small (fits in the palm of my hand), waterproof, has an interval timer, and HD video. Additional specifics can be found on the GoPro website (http://gopro.com/). For a photographer, the GoPro has one setting – On or Off, and does not have any user adjustable exposure settings. Also, it only comes with one lens. Are these limitations ?. No, since they free the photographer to concentrate on the photo, and not be burdened with adjusting exposure or wondering if they are using the right lens for the situation. For an active person wanting to photograph sports events, the GoPro accessories are available for attaching to bicycle handlebars, seat posts, helmets, a head and chest harness, and using the stick-on brackets can be attached to almost anything. The small size of the GoPro and the variety of available (and easily customized) brackets and harness allow a full range of movement for any sport or activity.

Now, the photographer can be in the action, photograph the action, and no longer burdened by a camera*.

In-Action Photography* refers to photography where the photographer is photographing the action while in the action. This differes from Action Photography, which is photography of an action (e.g. sports event) and does not specifically refer to the photographer being part of the action.
All the photos on this page were captured by the photographer.   Downhill skiing photos captured using a GoPro on a chest harness, and kite skiing photos by a GoPro attached on the ski tip using a custom bracket. Click on the photos to make them larger.

Downhill skiing – unburdened by a camera
Check the shadow – try that with a hand held camera !

 

 

 

 

Cutting the Soft Stuff – kite skiing

 

 

Shadow at lower right corner is the GoPro

More kite skiing photos are on this link

Roy’s Audiotronic

A blustery spring afternoon seemed like the perfect time to wander through Roy’s Audiotronic shop on the lower level of the Yk Mall in Yellowknife NWT.

Click on the image for a larger view.

To view the 360 degree animation click on this image

Click the icon on the upper right corner of the animation to get a full view. Click the mouse and drag the screen to move around.

This animation requires the Quicktime Player.

Camera gear: Nikon D700 and Samyang/Bower 8mm on a 7 foot pole. Four pictures were combined to create the panorama images.

Kite Skiing: Tips for Beginners

A few weeks ago and kite skiing friend (Chris – not his real name) mentioned that he was going to sell his kite –
“Why” I asked, “kiting is an awesome sport, what’s up”

Chris, is an emergency room doctor and over the past few months had seen several patients with serious kite skiing related head injuries. For Chris, the thrill of kite skiing was gone, replaced with the fear of a head injury.

As an avid kite skier, I had to know what had caused these injuries, and why were so many people getting seriously injured. Without providing specific details, Chris mentioned that the four casualties were all relatively new to the sport of kite skiing. Thinking back to when I started kite skiing 10 years ago, yes, I did have more accidents. Some of those accidents were due to the sport being new to Yellowknife and the lack of experienced kite skiers, some accidents due to my lack of experience, and other accidents related to doing stunts (e.g. intentionally getting lifted). Also, the kite that I purchased on-line was a whopping 4.9m (square meters). At the time, this was considered ‘far too big, and I would get hurt’. Fortunately, none of my crashes were serious and I quickly gained sills and experience.

Ten years later, I am still using that same kite. The kiting scene in Yellowknife has changed dramatically; more kiters, there is a licensed kite school and the kites are now 12 to 20 meters in area. You can’t even buy a kite as small as mine anymore. Nowadays, the kites are very different in design than my now vintage kite. A suitable analogy would be, my kite as a 1950’s sports car and modern kites akin to a Ford 350; big, powerful and with extra features like cruise control and airbags. Really, those new kites are big and powerful and can actually be flown with one hand !

So, going back to why have there been four serious kite skiing head injuries during the past few months ?. I don’t think we will ever know exactly what happened, and it would not be fair of me to speculate on what happened.

Instead, I’ve created a list of 10 tips to pass on to beginner kite skiers. These are based on personal experience of 10 yeas of kite skiing, and conversations with other, experienced kite skiers.

  1. Always wear a Helmet: Wearing a helmet can reduce the risk of brain injury when your head comes down hard on the snow.
  2. Watch the Clouds: Fast moving clouds are a warning that a wind pattern is imminent.
  3. Know your Wind Limit: Know your wind comfort zone and if the wind gets too strong, then pack up and go home.
  4. Watch for Obstructions: Keep your eyes on the path in front of you and do no watch only kite. Hitting a snowbank at high speed can be very painful.
  5. Stay Away from Bare Ice: The metal edges of skis (or snowboards) are not designed for ice. In a strong wind, they will slide out from under you.
  6. Use a Safety Harness: If you suddenly are overpowered by the wind and are out of control, a safety harness, connected to your break lines gives you the ability to completely let go of your kite and it will not blow away.
  7. Learn the Rules of Kite Skiing: Although the link refers to kite surfing, the rules and concepts are the same for kite skiing.
  8. Do Not Attempt Stunts until you have mastered the basic techniques.
  9. Icy Snow, epically after a thaw and freeze cycle is unforgiving. Sharp snow can shred your kite and you, and is really fast. I usually wait until the snow has softened. Your knees will than you.
  10. Get a lesson or two from a licensed instructor.

Have fun.

 

 

Interior View Greenstone Building

The Greenstone Building (also known as Government of Canada Building) was designed as a environmentally friendly building, and was the first building north of the 60th parallel to win a LEED Gold certification. Even from a distance, the four-story Greenstone Building in downtown Yellowknife can be recognized by its unique architecture.
Environmental “Green” features are incorporated at every level of the building, starting at the rooftop with a rain water collection for site irrigation and toilet flushing, solar panels and gigantic ‘towel rack’ (sun shield) on the entire south wall, together with various energy saving devices to decrease its energy demand, such as operable windows for ventilation instead of turning on on air conditioning, triple glazed windows, and high-efficiency mechanical systems to save on energy costs and reduce greenhouse gas emissions. Materials used during construction include a many re-used materials, include by‐products from burning coal added to the concrete, and carpets created from old carpet fibres and recycled milk jugs and pop bottles.

The interior design is based on Yellowknife’s mining heritage, with stairs representing a mining shaft, and abrupt off-sets on the floor to represent geological faults.

Click on the image for a larger view.

To view the 360 degree animation click on this image

Click the icon on the upper right corner of the animation to get a full view. Click the mouse and drag the screen to move around.

This animation requires the Quicktime Player.

Camera gear: Nikon D700 and Samyang/Bower 8mm on a 7 foot pole. Four pictures were combined to create the panorama images.

The Yellowknife Dump

From the Legislative Assembly to the Yellowknife city dump.

Scroll down to see the Images

The Yellowknife city dump is probably the only dump in North America where you are allowed to salvage, meaning that what ever you see – you can take home.

On weekends during the summer months the dump can be a busy place with line-ups just to get in. Although there do seem to be ‘professional salvagers’ collecting items of monetary value e.g. aluminum beverage cans, salvagers include persons from all levels of society – the rich and the needy. On a warm sunny day, ‘dumpers’ are known to linger and chat with fellow dumpers and salvagers. The conversation may be interrupted when something catches their eye as it is tipped out of a pickup truck. As times, salvagers have even offered to remove items from your truck even before you get a chance to unbuckle your seatbelt !.

During the past few years, the Yellowknife dump has become more organized. Pay the $5 dollar tipping fee at the entrance gate, and you pass the standard Blue Box recycling bins (tin cans, paper and plastic), to where the fun begins. The paint depot (pick up a can or two of paint – perfect for finishing off that living room wall in …really, what ever color you want), then the ‘white’ appliance area (stoves, refrigerators, hot water tanks etc), the wood area (seriously depleted during the winter !), and the scrap metal area.

Following the road, it goes past the battery collection area up the hill skirting a huge pile of tires to the the main section of the dump. Until a few years ago there was one dumping area for everything else. Now, there is a rotating Three Cell System; Dump Here, Salvage Here and the third area is closed – undergoing renovation (fancy word for bulldozers are in-action making space for next week). The Dump Here area is where you can find anything, and everything; furniture, tools, clothing, musical instruments, building supplies, appliances, toys, TVs, computers, even boats.

To view a 360 degree animation of the Three Cell area click on this image.


Click the icon on the upper right corner of the animation to get a full view. Click the mouse and drag the screen to move around.

In the wreaked cars area there are piles of cars in various states of dis-assembly. Once sufficiently picked over by salvagers, the wreaks are squishied in square bales for shipping smelters in southern Canada.

To view a 360 degree animation of the car salvage area click on this image

Click the icon on the upper right corner of the animation to get a full view. Click the mouse and drag the screen to move around.

The Yellowknife dump is so popular, that there is a weekly article in the Yellowknife newspaper (Walt Humphries – Tales from the Dump), and it has been featured on several TV programs, such as CBC Wayne Rostad “On the Road Again”, and numerous magazines including UpHere (One Man’s Junk is Another Man’s Treasure), Canadian Living (Go green: Shopping at the Yellowknife dump), the Walrus (The last great city dump. Throwing it all away in Yellowknife), and the New York Times (Rush to the Garbage Dump: There’s Gold to Be Mined).

We leave you with a final image of the Yellowknife Dump, photographically distorted to resemble a planet covered with wreaked cars.

Camera gear: Nikon D700 and Samyang/Bower 8mm on a 7 foot pole. Four pictures were combined to create the panorama images.

Legislative Building of the Northwest Territories

It seemed like a perfect afternoon to wander through the Legislative Building in Yellowknife NWT.

The NWT has a unique form of government known as Consensus government. The Premier is chosen from elected Members of the Legislative Assembly (MLAs), and turn chooses the executive council (cabinet) that forms government. The remaining MLAs form the unofficial opposition.

MLAs were elected on October 3rd, 2011, and the process is underway to choose a Premier.

Click on the image for a larger view.

Main floor lobby of the Legislative Building…

Upstairs lobby…

Interior of the Legislative Assembly…

To view the 360 degree animation click on this image

Click the icon on the upper right corner of the animation to get a full view. Click the mouse and drag the screen to move around.

This animation requires the Quicktime Player.

Camera gear: Nikon D700 and Samyang/Bower 8mm on a 7 foot pole. Four pictures were combined to create the panorama images.