Orthophotos

The 2009 orthophotos are the same resolution as the 2008, 2006, 2004, and 2002 orthophotos (10 cm) and are very high quality.

• The imagery was captured in a way to minimize building lean problem.
• Coverage for 2009 includes less area from Richmond, Sea island (YVR) and the North Shore in comparison to 2008.

The 2008 orthophotos are the same resolution as the 2006, 2004, and 2002 orthophotos (10 cm).

• The downtown area was taken from an altitude of 8000 feet to minimize building lean. The rest of the City was taken at 6000 feet.
• Coverage for 2008 is comparable to 2006.

These orthophotos were taken at 15 cm resolution, compared to normal of 10 centimetres. The result of this difference in resolution is that the photos are not as sharp as are those from 2006, 2004, and 2002 and they appear more coarse. The other significant difference is the weather conditions at the time of the flight - these orthophotos were needed quickly to help both the damage assessment and re-forestation planning processes. As a result, it was not possible to wait for ideal weather conditions.

The orthophotos were provided to both the Vancouver Board of Parks and Recreation and VanMap by the vendor.

The 2006 orthophotos are the same resolution as the 2004 and 2002 orthophotos (10 cm). In comparing the new ones with those from 2004 and 2002, you will notice a few differences:

• Some tall buildings show a very small amount of building lean but the lean is much less than it was in 2002. In 2004 for the most part there was no lean at all and some staff complained that as a result, there was no perspective to see whether a building was tall or short.
• There are some shadows from the taller buildings in 2006, but these shadows tend to be less dark than they were in 2004 and do not block the underlying features as much as they did in 2004. There were very few shadows in 2002 because the conditions were almost ideal and it is rare for that to happen. By and large, the April 2006 weather was not very conducive to the capturing of orthophotos.
• The area included for the 2006 orthophotos is larger than it was for 2004; it includes the City, the University Endowment Lands, Sea Island (YVR) and parts of Richmond and North Vancouver. Sea Island, Richmond, and North Vancouver were not included in the 2004 version.

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The downtown area 2005 Orthophotos were taken about noon time on March 30 2005. The image resolution of the orthophotos is 10 cm per pixel and this results from the 1:6000 photographs.

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Aerial photographs taken on July 31, 2004. These photos cover the foreshore at low tide from Wreck Beach to Jericho Beach. Tide Level: Photos were taken when the tide was at - 2.67 m. (lowest normal tide is - 3.0 m)

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The 2004 orthophotos were taken between 1:20 pm and 1:48 pm on March 28, 2004 and between 10:21 am and 12:10 pm on April 1, 2004. They are the same resolution as the 2002 orthophotos (10 cm) and it is quite rare to find orthophotos with a better resolution. In comparing the new ones with those from 2002, you will notice three differences:

• The building lean problem that existed in the downtown and West End areas has been virtually eliminated. This makes it possible to see the streets and real roof lines to a greater degree than in 2002.
• There are more shadows from the taller buildings in 2004 than in 2002. This results from the weather and the time of day that the photos were taken. The conditions for the 2002 orthophotos were almost ideal; we were not quite as fortunate in April 2004.
• The 2004 Orthophotos were taken for the City of Vancouver and the University Endowment Lands and therefore exist for a smaller area than in 2002 (which also included Sea Island YVR and parts of Richmond and North Vancouver).

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You will notice that these are much clearer than those taken in 1999. In part this stems from the airplane flying at 5,000 to 6,000 feet rather than 20,000 feet as it did in 1999. The resolution is 10 cm.

In certain areas of the City, primarily Coal Harbour and the more densely populated areas of the downtown and the West End, you will find many places where there is substantial building lean. Building lean is when the roof of the building shown appears to lean over the street and obscure a portion of the street from view. This results from the photoscale (1:6000) and from the amount of forward, backward, and side overlap in the photographs. In order to get the high resolution image it was necessary to fly at the low elevation and with specific camera settings. The technicians manipulated the overlapping photographs to resolve some areas but in the densest areas this ability was restricted by the availability of suitable information.

The best option for resolving this issue would be to do a future flyover specifically in the downtown and West End areas. This flight would be at a higher elevation and would utilize greater overlap in all directions. Through this process most of the building lean problems could be resolved. The City will be looking at this and other options in Spring 2003. In the meantime, the 1999 orthophotos will remain in VanMap as a viewing option.

The new orthophotos cover Sea Island (YVR), a small amount of Richmond, UEL, and a small amount of Burnaby and the North Shore.

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The 1999 orthophotos were taken on March 19, 1999. The September 2001 release of VanMap enhanced the orthophotos to have them available continuously at any scale. 1999 was the first time orthophotos were made broadly available to staff. They were flown at a resolution of 25 cm and are not as good as those from subsequent years due to resolution, color balancing, and other technical factors.

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