topic Re: What is PhotoIndex and what does it for and how do I use it ? in Imagery and Remote Sensing Questions

What is PhotoIndex and what does it for and how do I use it ?

DEAF_PROBERT_68 — Mon, 05 Feb 2018 17:24:20 GMT

This is all new to me about learning how to use Aerial Photos. I have a very old ones that that are dated back to 1938 and I am having a really hard time to identify features there. I have them that are scanned at scale of 20,000. They are most on the mountainous areas and it lacks the features that I could find them.

My question to you what is Photo Index shapefile I have here? They are point shapefile that shows the flight that took them. How can I use it ?

I plan on to using to orthorectify them through ERDAS 2016 Imagine AutoSync.. I believe I have them about at least 3,000 all over my forest here.

I am not really familiar about them very much but I have google it around online and found some good information.

https://www.asprs.org/a/publications/proceedings/Sacramento2012/files/Ma.pdf

http://depts.washington.edu/pnwcesu/reports/J8W07110015_Final_Report.pdf

Do you have a website that discuss about them or some examples that may be helpful to me or can I look at them?

Re: What is PhotoIndex and what does it for and how do I use it ?

CodyBenkelman — Mon, 05 Feb 2018 17:43:46 GMT

Robert

If you start at http://esriurl.com/imageryworkflows and then look for this link

"Check out our ArcGIS Online Group for more tools"

in that Group you will find a workflow for Historical aerial photos (direct link http://www.arcgis.com/home/item.html?id=d1b4e3afeda7405fb34578207f0ad256 ). The photo index is a valuable input, to provide ArcGIS with an approximate position for the camera location to capture each image.

By following that workflow and inputting the metadata from the photo index into the "Frames Table" you should be able to position each image on the ground, but note the accuracy will depend on whether you have other metadata e.g. for the camera model. Quoting from the documentation of the Historical Imagery workflow:

This workflow uses the Mosaic Dataset within ArcGIS (and the Frame Camera Raster Type) to manage and rectify scanned images (on-the-fly) to approximately georeference them. The Mosaic Dataset will reference the scanned image files in their original format and apply approximate orientation parameters to perform the image georeferencing. If desired, the user has the option to refine the orientation parameters as required to achieve better accuracy, but be aware the resulting product should not be considered an orthorectified image unless full aerotriangulation is applied, and an accurate DEM is used.

Cody B

Re: What is PhotoIndex and what does it for and how do I use it ?

DEAF_PROBERT_68 — Thu, 08 Feb 2018 21:25:19 GMT

Thank you but it does not answer to my question about Photo Index. I could not find it...

Re: What is PhotoIndex and what does it for and how do I use it ?

PeterBecker — Thu, 08 Feb 2018 22:07:56 GMT

A photo index is a map that was typically created by the organization that originally flew the imagery that provided an overview of where the images were taken. You have to think back to what was available in the 1940's to create such an overview map. There were two main ways to create this. A) The navigator that flew the mission or someone else with knowledge of the area would mark on a map the approx location of each image or the first an last image of a run onto an existing map. B) A print laydown would be produced, which is really an analog mosaic of contact prints that was then photographed and some coordinates etc added. These Photo Indexes are typically kept with the films and the provider of the scanned images may be able to provide the photo index. The photo index is then typically scanned, georeferenced and digitized. The result of this process is a point feature class (or SHP file) that provide the approximate location of each photo center. These PhotoIndex files are used to initialize the creation of mosaic datasets which are the first stage in the process of georeferencing large collections of such imagery.

Note that if you want to manually georeference the images this capability is also available in ArcGIS. For some image one you have an approx location you can use the autogreoreferencing feature to automatically control points between the image to be georeferenced and an image base (such as world Imagery of other georeferenced image). Especially with old imagery finding such control can be difficult an it it advised to use the OrthoMapping capabilities available with ArcGIS desktop advanced.

Re: What is PhotoIndex and what does it for and how do I use it ?

DEAF_PROBERT_68 — Fri, 09 Feb 2018 16:39:48 GMT

Thank you. Is there an example that can I read more about this out there on the internet like an example of what a photo index looks like etc ?

I do believe they were taught in Remote Sensing course or Image Processing course , correct ?

Re: What is PhotoIndex and what does it for and how do I use it ?

PeterBecker — Fri, 09 Feb 2018 16:48:31 GMT

See Aerial Photo Mosaics | The Long Term Archive

Re: What is PhotoIndex and what does it for and how do I use it ?

DEAF_PROBERT_68 — Wed, 14 Feb 2018 15:24:15 GMT

Thank you and it is good information but still not provide me much deeper information on how one can retrieve the point shapefrile from each aerial photography ? Doesn't make any sense to me...

Re: What is PhotoIndex and what does it for and how do I use it ?

DanPatterson_Retired — Wed, 14 Feb 2018 15:35:27 GMT

You said you have the shapefiles... what is in the attribute table of them? is there some field that references a photo ID number or something? The aerial photographs wouldn't contain the shapefile information, it would be the other way around.

Re: What is PhotoIndex and what does it for and how do I use it ?

DEAF_PROBERT_68 — Wed, 14 Feb 2018 15:40:51 GMT

Give me a minute and I am going to post this point shapefile...

BTW, how do I add the zip file for this point shapefile so you all can see what it is..

It shows you the point in a UTM NAD 1983 in ArcMap but it lacks the attribute table..

Re: What is PhotoIndex and what does it for and how do I use it ?

DanPatterson_Retired — Wed, 14 Feb 2018 15:45:38 GMT

why don't you just open the table and report or screen-grab what is contained inside

Re: What is PhotoIndex and what does it for and how do I use it ?

DEAF_PROBERT_68 — Wed, 14 Feb 2018 15:51:12 GMT

Ok, sir I will do that and I will do my best to make it bigger picture HA HA

Re: What is PhotoIndex and what does it for and how do I use it ?

DEAF_PROBERT_68 — Wed, 14 Feb 2018 15:58:23 GMT

Overview of the Photo Index over the Pike and San Isabel National Forest ( See red hatch with red outline ). The points here you see is black dot color.

Zoom in smaller area and show you the attribute table.. Does not say Latitude and Longitude but How in the world did they put the point with the UTM reference ??

Here you go... and tell me i can go and find out more information..

This shapefile we have came from a contractor who does the scanning the aerial photos.

Now I select a point and use the identify tool to show me the information about that point..

Thoughts how did they do that ?

Re: What is PhotoIndex and what does it for and how do I use it ?

DanPatterson_Retired — Wed, 14 Feb 2018 16:08:22 GMT

The Shape field has the actual coordinate information just like any other shapefile. You can get the longitude and latitude and/or UTM coordinates using tools in ArcMap that I am sure you have used before.

Each point in that shapefile denotes an associated photo... therefore your photos on their associated rolls are the ones that belong with that point.

That does not however mean that you can see the image on screen other than by hyperlinking (a totally separate issue) or manually opening up the photo.

I suspect that what you want to do is use... Mosaic Datasets to somehow create the big 'picture' that you want to see. I suspect that the point location might be something like the centre or something else of the photo.

If you can open one of the photos AND it has real world coordinates (like utm or long/lat) then your photos are gis ready.

If you don't see real world coordinates for your photos... you have a big job ahead of you and some reading and strategizing to do to formulate a work plan... this is where contracting out is useful

Re: What is PhotoIndex and what does it for and how do I use it ?

DEAF_PROBERT_68 — Wed, 14 Feb 2018 16:17:09 GMT

Aww. I see. I am thinking that when the flight flew up in the air and the camera took pictures below and snapshot of each photo to denote that photo ? Correct ..

Re: What is PhotoIndex and what does it for and how do I use it ?

DanPatterson_Retired — Wed, 14 Feb 2018 16:22:46 GMT

Robert....

in 1938, to use one of your dates...

there were no digital cameras... the photos were printed on photo paper
your photos are obviously scanned from the originals
Shapefiles did not exist
and there was no gps to auto-register a digital photo (since it didn't exist) with flight coordinates...

Someone scanned the photos... made the association between the photos and plane location and produce the shapefile locations which represented the flight plan.

Re: What is PhotoIndex and what does it for and how do I use it ?

DEAF_PROBERT_68 — Thu, 22 Feb 2018 16:50:04 GMT

Well, here I am done with georegistration using ERDAS Imagine 2016 using AutoSync.. It is not that bad but here is the screenshot of what I did.. so I have a lot of raw aerial photos that I have to do..so it is fun !