Mapping Scale and Photo scale in Digital cameras

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Michael Younan

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Jun 17, 2016, 2:11:17 PM6/17/16
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Dear all

 

I need assistance if possible for those who are professionals in the photogrammetry profession

 

I have a question on the Digital photogrammetry specifications who want all 3 items below to be compliant to the work

 

Today we are using digital cameras and the client is insisting that the

 

1.      “ Aerial Photo scale = 7* Mapping Scale “  for 1:1000 mapping scale ,

2.      “Contour Interval of 1 meter ( Contour Interval = flying height / 1800 to 2100) “

3.      Spatial Resolution (pixel\cell size or GSD) of 10 cm (D=d*h/f, where D is pixel size on the ground, d is the pixel size of the sensor or scanner, h is the flying height and f is the focal length of the camera )“

 

The camera we are using is Phase I with 80 MP back and the lens is 52 mm, and we have another client who has Eagle 100 mm, and another that have Leica Cameras and other has an MS Eagle UltraCAM

 the height of flight above ground with GSD calculation is half the height of flight for the first 2 items

 

10 cms GSD is good for map scale of 1:600 and up to 1:1250 is this correct?

 

I am arguing with the client that the old formula of Map Scale 1:1000 with a factor of 7*altitude is not anymore valid in the digital camera world and the c-factor with contour lines is not also valid , as mentioned in ASPRS new standards. These two items 1 and 2 are valid for frame film camera but not for digital cameras of today

 

The GSD is the only factor that rules and the first 2 items are not valid for the new era of digital sensors and cameras

 

Is there a direct relationship between Map Scale and GSD in scientific formulas

 

Please send me any whitepapers on this issue or links for references and comment on this issue , or put me in connection with a person that can advise

 

 

 

Eng. Michael Younan

GSE, Good Shepherd Engineering

PalMap, Palestine Mapping Center

Tel: 00 970 202744728

Fax: 00 970 2 2751204

US Tel : 00 1 562 295 7132

Mobile: 00 972 522 632461 / 00 970 594 3333 04

Skype: palmap_org

 

www.gsecc.com  / www.palmap.org   / in...@gse.ps

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Yuri Raizman

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Jun 17, 2016, 4:11:15 PM6/17/16
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Hi Michael
I recommend you to use new mapping instruction published by Survey of Israel. There is a definition there between scale and resolution. Regards, Yuri

Sent from my iPhone

Michael Younan

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Jun 20, 2016, 4:47:59 AM6/20/16
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Thanks Yuri

 

Can you please send me the link

 

Eng. Michael Younan

GSE, Good Shepherd Engineering

PalMap, Palestine Mapping Center

Tel: 00 970 202744728

Fax: 00 970 2 2751204

US Tel : 00 1 562 295 7132

Mobile: 00 972 522 632461 / 00 970 594 3333 04

Skype: palmap_org

 

www.gsecc.com  / www.palmap.org   / in...@gse.ps

P Please do not print this email unless it is absolutely necessary. Spread environmental awareness

 

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