help regarding Photogrammetry

hi all

Happy new year

Having this problem statement

"we have plenty of aerial photographs taken from directly below
airplane .we know the height of the airplane for the point directly
below the plane ,suppose it is the middle point of the picture.we know
the GPS coordinates of the plane.than how can we find the GPS
coordinates of the other points in the picture. let we assume that
camera is straight , we can take images at different distance, when
distance is known, we can consider them as paired images.

now i am trying to search some latest papers and data from net.Can
anybody help me regarding this matter.

any kind of a help will be appreciated ........thanks

Hi tenveer,

If you know your:
. height above ground level; and
. the camera lens focal length
then the maths to work out the relative distance from the center of the image to
any point on the image is quite straight-forward -
provided all parts of the scene are the same altitude. If you also know the
image sensor/film size, working out the field of view is
also quite straight-forward.

Below my sig is the code for a SYLK file you can save to a text file (eg named
optics.slk) and open with Excel. It's something I've
put together for photography purposes, and there's stuff in there that may not
interest you. However, if you input the camera's
sensor/film dimensions (with as much accuracy as you can find), lens focal
length and the camera's height above ground level, the
calculator will return the corresponding field of view dimensions. If you're
working with an uncropped print of the captured image,
knowing the field of view dimensions will allow you to express the distance
between any two points on the image as a percentage of
the image width and that easily translates to a percentage of the field of view
(which you can then convert to whatever units you
prefer to work with). From there, provided you know the image's orientation, you
should be able to work out the lat/lon of any point
on the image. If you're working with very large fields of view, you'll also need
to allow for the curvature of the earth in your
calculations. Of course, all this assumes the lens doesn't distort the image in
any way - something that often isn't true.

You'll notice there's a cell named 'Smallest Detail Resolved at Subject
Distance:'. This is governed by the lens focal length,
altitude, print density and print viewing distance - not by the pixel size, per
se, of a digital camera. The Calculated Print
Viewing Distance is per Kodak research, but you can use something different if
you prefer.

--
Cheers,
macropod


ID;PWXL;N;E
P;PGeneral
P;P0
P;P0.00
P;P#,##0
P;P#,##0.00
P;P#,##0;;\-#,##0
P;P#,##0;;[Red]\-#,##0
P;P#,##0.00;;\-#,##0.00
P;P#,##0.00;;[Red]\-#,##0.00
P;P"$"#,##0;;\-"$"#,##0
P;P"$"#,##0;;[Red]\-"$"#,##0
P;P"$"#,##0.00;;\-"$"#,##0.00
P;P"$"#,##0.00;;[Red]\-"$"#,##0.00
P;P0%
P;P0.00%
P;P0.00E+00
P;P##0.0E+0
P;P#\ ?/?
P;P#\ ??/??
P;Pd/mm/yyyy
P;Pd\-mmm\-yy
P;Pd\-mmm
P;Pmmm\-yy
P;Ph:mm\ AM/PM
P;Ph:mm:ss\ AM/PM
P;Ph:mm
P;Ph:mm:ss
P;Pd/mm/yyyy\ h:mm
P;Pmm:ss
P;Pmm:ss.0
P;P@
P;P[h]:mm:ss
P;P_-"$"* #,##0_-;;\-"$"* #,##0_-;;_-"$"* "-"_-;;_-@_-
P;P_-* #,##0_-;;\-* #,##0_-;;_-* "-"_-;;_-@_-
P;P_-"$"* #,##0.00_-;;\-"$"* #,##0.00_-;;_-"$"* "-"??_-;;_-@_-
P;P_-* #,##0.00_-;;\-* #,##0.00_-;;_-* "-"??_-;;_-@_-
P;Pdd/mm/yyyy
P;Pdd\-mmm\-yy
P;Pdd\-mmm
P;Pdd/mm/yyyy\ h:mm
P;P0.000
P;P0.0000
P;P\(3#.00
P;P0.0
P;P0.00\Nk
P;P0.00000
P;FArial;M200
P;FArial;M200
P;FArial;M200
P;FArial;M200
P;EArial;M200
P;EArial;M200
P;EArial;M200;SB
P;EArial;M200;SB;L11
P;EArial;M200
P;EArial;M200
P;EArial;M200;SB
P;EArial;M200;SB
P;EArial;M200;SB;L11
P;EArial;M160
F;P0;DG0G8;SM9;M255
B;Y98;X4;D0 0 97 3
O;P;L;D;V0;K47;G100 0.001
F;W1 1 43
F;W2 2 9
F;W3 3 20
F;W4 4 4
F;P0;FG0R;SDM7;Y1;X1
F;SDM7;X2
F;SDM7;X3
F;P0;FG0C;SDM7;X4
C;K"Nominal (3-stops"
F;P0;FG0R;SDM7;Y2;X1
C;K"Film Width:"
F;SDM8;X2
C;N;K36
C;X3;K"mm"
C;X4;K0.5
F;P0;FG0R;SDM7;Y3;X1
C;K"Film Height:"
F;SDM8;X2
C;N;K24;ER2C2*2/3
C;X3;K"mm"
C;X4;K0.53
F;P0;FG0R;SDM7;Y4;X1
C;K"35mm Field of View Crop Factor:"
F;P2;FF2G;X2
C;K1;E(36^2+24^2)^0.5/(R2C2^2+R3C2^2)^0.5
F;P0;FG0L;X3
C;K"(1:1.000)";E"(1:"&TEXT(1/R4C2,"0.000)")
C;X4;K0.56
C;Y5;K0.6
F;P0;FG0R;SDM7;Y6;X1
C;K"Sensor Width:"
F;SDM13;X2
C;N;K0
C;X3;K"pixels"
C;X4;K0.63
F;P0;FG0R;SDM7;Y7;X1
C;K"Sensor Height:"
F;SDM13;X2
C;N;K0;ER6C2*R3C2/R2C2
C;X3;K"pixels"
C;X4;K0.67
F;P0;FG0R;SDM7;Y8;X1
C;K"Megapixels:"
F;P2;FF2G;X2
C;K0;ER6C2*R7C2/1000000
C;X4;K0.7
C;Y9;K0.75
F;P0;FG0R;SDM7;Y10;X1
C;K"Required Print Width:"
F;SDM8;X2
C;N;K150
C;X3;K"mm (5.91in)";E"mm ("&TEXT(R10C2/25.4,"0.00")&"in)"
C;X4;K0.8
F;P0;FG0R;SDM7;Y11;X1
C;K"Required Print Height:"
F;SDM8;X2
C;N;K100;ER10C2*R3C2/R2C2
C;X3;K"mm (3.94in)";E"mm ("&TEXT(R11C2/25.4,"0.00")&"in)"
C;X4;K0.85
F;P0;FG0R;SDM7;Y12;X1
C;K"Negative Enlargement:"
F;P40;FF3G;X2
C;K4.16666666666667;EMAX(R10C2/R2C2,R11C2/R3C2)
C;X4;K0.9
F;P0;FG0R;SDM7;Y13;X1
C;K"Print Diagonal:"
F;P1;FI0G;X2
C;K180.277563773199;E(R10C2^2+R11C2^2)^0.5
C;X3;K"mm (7.10in)";E"mm ("&TEXT(R13C2/25.4,"0.00")&"in)"
C;X4;K0.95
F;P0;FG0R;SDM7;Y14;X1
C;K"Calculated Print Viewing Distance:"
F;P1;FI0G;X2
C;K337.63166028828;E125.1*LN(R13C2)-312.2
C;X3;K"mm (13.29in)";E"mm ("&TEXT(R14C2/25.4,"0.00")&"in)"
C;X4;K1
F;P0;FG0R;SDM7;Y15;X1
C;K"Preferred Print Viewing Distance:"
F;P1;FI0G;SDM8;X2
C;N;K337.63166028828;ER14C2
C;X3;K"mm (13.29in)";E"mm ("&TEXT(R15C2/25.4,"0.00")&"in)"
C;X4;K1.05
F;SDM7;Y16;X1
C;X4;K1.1
F;P0;FG0R;SDM7;Y17;X1
C;K"Focal Length:"
F;SDM8;X2
C;N;K50
C;X3;K"mm"
C;X4;K1.2
F;P0;FG0R;SDM7;Y18;X1
C;K"Angle of View (w):"
F;P44;FF2R;X2
C;K39.5977527090499;E2*DEGREES(ATAN(R2C2/(2*R17C2)))
C;X4;K1.25
F;P0;FG0R;SDM7;Y19;X1
C;K"Angle of View (h):"
F;P44;FF2R;X2
C;K26.9914665615916;E2*DEGREES(ATAN(R3C2/(2*R17C2)))
C;X4;K1.3
F;P0;FG0R;SDM7;Y20;X1
C;K"Subject Distance:"
F;SDM8;X2
C;N;K4
C;X3;K"m (13.12ft)";E"m
C;X4;K1.4
F;P0;FG0R;SDM7;Y21;X1
C;K"Field Of View (w):"
F;P40;FF3G;X2
C;K2.844;EMAX(0,(R20C2*1000/R17C2-1)*R2C2/1000)
C;X3;K"m (9.33ft)";E"m
C;X4;K1.5
F;P0;FG0R;SDM7;Y22;X1
C;K"Field Of View (h):"
F;P40;FF3G;X2
C;K1.896;ER21C2*R3C2/R2C2
C;X3;K"m (6.22ft)";E"m
C;X4;K1.6
F;P0;FG0R;SDM7;Y23;X1
C;K"Image Magnification:"
F;P40;FF3R;X2
C;K0.0126582278481013;ER17C2/(R20C2*1000-R17C2)
F;P0;FG0L;X3
C;K"(1:79.000)";E"(1:"&TEXT(1/R23C2,"0.000)")
C;X4;K1.7
F;P0;FG0R;SDM7;Y24;X1
C;K"Smallest Detail Resolved at Subject Distance:"
F;P40;FF3G;X2
C;K2.79317972241176;ER33C2*R21C2*1000/R10C2
C;X3;K"mm (0.110in) diameter";E"mm ("&TEXT(R24C2/25.4,"0.000")&"in) diameter"
C;X4;K1.8
F;SDM7;Y25;X1
C;X4;K1.9
F;P0;FG0R;SDM7;Y26;X1
C;K"Nominal Aperture Ratio:"
F;P42;FF2R;SDM8;X2
C;N;K4
C;X3;K"(Actually (3:4.000)";E"(Actually
(3:"&TEXT((2^(1/12)^((MATCH(R26C2,C4)-14))),"0.000")&")"
C;X4;K2
F;P0;FG0R;SDM7;Y27;X1
C;K"Actual Aperture Diameter:"
F;P2;FF2R;X2
C;K12.5;ER17C2/(2^(1/12)^((MATCH(R26C2,C4)-14)))
C;X3;K"mm (0.492in)";E"mm ("&TEXT(R27C2/25.4,"0.000")&"in)"
C;X4;K2.1
F;P0;FG0R;SDM7;Y28;X1
C;K"Actual Aperture Area:"
F;P2;FF2R;X2
C;K122.718463030851;ER27C2^2/4*PI()
C;X3;K"mm (4.831in)";E"mm ("&TEXT(R28C2/25.4,"0.000")&"in)"
C;X4;K2.25
F;SDM7;Y29;X1
F;SDM7;X2
F;SDM7;X3
C;X4;K2.4
F;P0;FG0R;SDM7;Y30;X1
C;K"Required Print Resolution:"
F;P2;FF2G;SDM8;X2
C;N;K1.5;E90/60
C;X3;K"arcminutes (1'30'')";E"arcminutes
("&INT(R30C2)&"'"&MOD(INT(R30C2*60),60)&"'')"
C;X4;K2.5
F;P0;FG0R;SDM11;Y31;X1
C;K"Diffraction Limit Aperture Ratio:"
F;P2;FF2G;SM10;X2
C;K25;EINDEX(R1C4:R98C4,MATCH(R32C2/0.0013538337,R1C4:R98C4))
C;X3;K"(Actually (3:25.398)";E"(Actually
(3:"&TEXT((2^(1/12)^((MATCH(R31C2,C4)-14))),"0.000")&")"
C;X4;K2.7
F;P0;FG0R;SDM7;Y32;X1
C;K"Circle of Confusion Diameter:"
F;P41;FF4G;X2
C;K0.0353567053469843;ETAN(RADIANS(R30C2/120))*2*IF(R15C2=0,R14C2,R15C2)/MAX(R10C2/R2C2,R11C2/R3C2)
C;X3;K"mm (0.00139in)";E"mm ("&TEXT(R32C2/25.4,"0.00000")&"in)"
C;X4;K2.8
F;P0;FG0R;SDM7;Y33;X1
C;K"Printed Blur Circle Diameter:"
F;P41;FF4G;X2
C;K0.147319605612435;ER32C2*R12C2
C;X3;K"mm (0.0058in)";E"mm ("&TEXT(R33C2/25.4,"0.0000")&"in)"
C;X4;K3
F;P0;FG0R;SDM7;Y34;X1
F;P41;FF4G;X2
C;X4;K3.2
F;P0;FG0R;SDM7;Y35;X1
C;K"Hyperfocal Distance:"
F;P40;FF3G;X2
C;K17.7269864122339;E(R17C2^2/(R17C2/R27C2*R32C2)+R17C2)/1000
C;X3;K"m (58.16ft)";E"m
C;X4;K3.3
F;P0;FG0R;SDM7;Y36;X1
C;K"Nearest Point In Focus:"
F;P2;FF2G;X2
C;K3.26943126985726;E(R35C2-R17C2/1000)*R20C2/(R35C2+R20C2-R17C2*2/1000)
C;X3;K"m (10.73ft)";E"m
C;X4;K3.5
F;P0;FG0R;SDM7;Y37;X1
C;K"Furthest Point In Focus:"
F;P2;FF2G;X2
C;K5.1510173846984;EIF(R35C2<=R20C2,"Infinity",(R35C2-R17C2/1000)*R20C2/(R35C2-R20C2))
C;X3;K"m (16.90ft)";EIF(R37C2="Infinity","","m
C;X4;K3.8
F;P0;FG0R;SDM7;Y38;X1
C;K"Depth of Field:"
F;P2;FF2G;X2
C;K1.88158611484114;EIF(R35C2<=R20C2,"Infinite",R37C2-R36C2)
C;X3;K"m (6.17ft)";EIF(R38C2="Infinite","","m
C;X4;K4
F;P0;FG0R;SDM7;Y39;X1
C;X4;K4.25
F;P0;FG0R;SDM7;Y40;X1
C;K"Minimum Print Density:"
F;P2;FF2G;X2
C;K13.5759255645956;E2/R32C2/R12C2
C;X3;K"lines/mm (345ppi)";E"lines/mm ("&TEXT(R40C2*25.4,"0")&"ppi)"
C;X4;K4.5
F;P0;FG0R;SDM7;Y41;X1
C;K"Equivalent Megapixels:"
F;P2;FF2G;X2
C;K2.76458632403162;E(R2C2*R3C2*(R12C2*R40C2)^2)/10^6
C;X4;K4.75
C;Y42;K5
F;P0;FG0C;SDM12;Y43;X2
C;K"Maximum Print Size @ 13.58 lines/mm (345ppi)";E"Maximum Print Size @
"&TEXT(R[-3]C,"0.00 ")&R[-3]C[+1]
C;X4;K5.3
F;P0;FG0R;SDM7;Y44;X1
C;K"Width:"
F;P43;FF1G;X2
C;K150;EIF(R6C2=0,R2C2*R12C2,R6C2/R40C2)
C;X3;K"mm (5.91in)";E"mm ("&TEXT(R44C2/25.4,"0.00")&"in)"
C;X4;K5.6
F;P0;FG0R;SDM7;Y45;X1
C;K"Height:"
F;P43;FF1G;X2
C;K100;EIF(R7C2=0,R3C2*R12C2,R7C2/R40C2)
C;X3;K"mm (3.94in)";E"mm ("&TEXT(R45C2/25.4,"0.00")&"in)"
C;X4;K6
C;Y46;K6.3
C;Y47;K6.7
C;Y48;K7
C;Y49;K7.5
C;Y50;K8
C;Y51;K8.5
C;Y52;K9
C;Y53;K9.5
C;Y54;K10
C;Y55;K10.5
C;Y56;K11
C;Y57;K12
C;Y58;K12.7
C;Y59;K13.5
C;Y60;K14
C;Y61;K15
C;Y62;K16
C;Y63;K17
C;Y64;K18
C;Y65;K19
C;Y66;K20
C;Y67;K21
C;Y68;K22
C;Y69;K24
C;Y70;K25
C;Y71;K27
C;Y72;K28
C;Y73;K30
C;Y74;K32
C;Y75;K34
C;Y76;K36
C;Y77;K38
C;Y78;K40
C;Y79;K42
C;Y80;K45
C;Y81;K48
C;Y82;K50
C;Y83;K54
C;Y84;K57
C;Y85;K60
C;Y86;K64
C;Y87;K68
C;Y88;K72
C;Y89;K76
C;Y90;K80
C;Y91;K85
C;Y92;K90
C;Y93;K96
C;Y94;K100
C;Y95;K108
C;Y96;K114
C;Y97;K120
C;Y98;K128
E

wrote:



I suggest you consult any up-to-date textbook on photogrammetry. This
is a perfectly standard setup for photogrammetry; it isn't a research
topic. Most modern photogrammetric software will handle this scenario;
we do it routinely in the group I work in.

You will require a few ground control points; because you have not
measured the orientation of the camera, you need GCPs to orient the
photogrammetric model in space.

Paul

yah paul you r right .........this is jst a ordinary standard
case ...but its just the begning point and good setup to start with to
understand the concepts ......than i have to go for the oblique
photogrammetry .......but remember i am new comer

paul please can you explain the following paragraph in more
detail ...........

"You will require a few ground control points; because you have not
measured the orientation of the camera, you need GCPs to orient the
photogrammetric model in space. "

because i have already explained that i already have large set of
images,and info described earlier in the problem statement
.....

thanks and regards

wrote:



With the information you have, you can create a photgrammetric model
using the camera centres and tie points that most packages with
generate automatically; YMMV! But without additional information, the
model is not fixed in space; you don't have the orientation of the
camera with respect to vertical. And the orientation need to be
determined pretty accurately; I can't give you exact numbers, but it
is in milliradians; far less than the control of orientation that an
aircraft has. We don't either, but if you have surveyed locations on
the ground - only a few, if they're well distributed and accurately
determined and located on the photos, 4 or 5 will do - these will
ensure that the photgrammetric model is correctly oriented in space.
Without them you will have residual systematic errors.

The GCPs need not be determined at the same time as the photography,
as long as the surface is invariant.

Oblique photography is not a problem; the photogrammetric methodology
is exactly the same. It was a problem in the days of mechanical
stereoplotters, because of limits on the movement of the various parts
of the equipment. But with soft-copy photogrammetry it shouldn't be a
problem. You will lose accuracy in the distance of the photos, but
that's pretty obvious.

We use Leica Photogrammetric Suite, and there is nothing in the
problem as posed that it couldn't handle.