Messages

1

General / Re: Converting outputs to a new coordinate system using Convert feature

« on: February 05, 2025, 10:33:57 PM »

I am not familiar with using commands in the Console window. Here I am trying some of the inputs you have in your example.

2

General / Re: Reduce distortion for trees in orthomosaic

« on: February 05, 2025, 12:23:48 AM »

You could make a DTM terrain model, where Tools > Point Cloud > Classify Ground Points, then make a new DSM using only the ground points in the point classes. It'll will "flatten" the trees in your ortho.

3

General / Re: Metashape not reading image locations

« on: February 04, 2025, 10:22:12 PM »

You can try hand selecting those images, plus a few additional already aligned images that surround it, right click in the list of images on the right hand pane and say "Align Selected Images." If that doesn't help, then I usually realign all the images but try different tie point/key point limit parameters that are less binding.

4

General / Re: Converting outputs to a new coordinate system using Convert feature

« on: February 04, 2025, 10:13:53 PM »

My benchmarks are actually Propeller AeroPoints that I'm using as check points. When they are converted to WGS84 / UTM + WGS84 EllipHT (using NOAA Vertical Datum Converter, one example attached), they are pretty matched up with my DSM exported from Agisoft in WGS84 / UTM + WGS84 EllipHT. This is the initial projection. I get only a ~7cm difference between my Aero check points and my DSM.

I think I am getting all the same DSM elevations because when I go to Export DEM after doing each Convert option, I am selecting NAD83(2011) / UTM Zone 12N + NAVD88 Geoid 12b from the drop down menu of the Export DEM window (see attached). I do the convert function just before this, but maybe me picking from the drop down menu is cancelling things out? If this is incorrect, how does one export a converted projection DEM?

5

General / Re: Converting outputs to a new coordinate system using Convert feature

« on: February 01, 2025, 01:55:57 AM »

Thanks for sharing the Epoch 2010 and 2025.1, Paulo.

So I did a convert test using 3 variations:

1. "NAD83(2011) to WGS84" in the Custom drop down menu, plus hand selecting the us_noaa_g2012b.tif from my Geoids folder (name does not stick in window, but the console window recognizes it)

2. Parameters from Epoch 2012

3. Parameters from Epoch 2025.1

I export the DSM after each convert test and view them in ArcGIS.

The elevations are all identical, as if changing the parameters did not do anything to the elevations. I guess I was expecting some slight variations?

Meanwhile, the elevations I'm getting are in the right ballpark, but are still all off 0.6 meters from my known benchmarks.

When the DSM was still in WGS84 UTM (pre convert), my elevations were only 0.05 m off from my known benchmarks.

6

General / Re: Converting outputs to a new coordinate system using Convert feature

« on: January 31, 2025, 02:14:48 AM »

@Paulo, thanks for the additional tips regarding the seven transformation parameters.

I want to go from WGS84 to NAD83(2011) NAVD88 Geoid 12B. How do I get parameters for the opposite direction, starting in WGS84?

Now I'm trying to find where I can look up the seven parameters myself. I'm searching all sorts of words on National Geodetic Survey and Google and it's not clear. Hoping there is some king of user interface it can populate these values for me as I have more projections/parameter needs.

7

General / Re: Converting outputs to a new coordinate system using Convert feature

« on: January 29, 2025, 09:47:19 PM »

I have the Geoid 12B TIF in the C: directory, we use it often and navigate to the TIF in the Datum Transformation Parameters window

In the Datum Transformation Parameters window, it only lets me select:

CUSTOM
NONE
NAD83(2011) to WGS84 (1) (EPSG::9974)

The latter seems the closest, but how do I get it to say the opposite? From WGS84 (1) (EPSG::9974) to NAD83(2011) ?

8

General / Converting outputs to a new coordinate system using Convert feature

« on: January 24, 2025, 09:52:02 PM »

Hello,

I am wanting to convert our outputs (ortho, DSM) into a new projection system using the tips on this HelpDesk page: https://agisoft.freshdesk.com/support/solutions/articles/31000151182-conversion-between-the-coordinate-systems

Our Agisoft set projection is WGS 84 / UTM Zone 12N + WGS84 Ellipsoid HT. This is LiDAR data it it captured in this projection.

However, we want our DSM and ortho - without ground control points (like we normally do) - converted into NAD83 (2011) UTM Zone 12N + NAVD88 Geoid 12B.

(Normally our GCP are in the desired projection and that is how we get our end projects in our desire projection, but this LiDAR doesn't use GCP.)

Having just discovered the Convert button in the Reference menu, I'm trying to make it work. It seems to convert the XY to the new projection, but not the Z so looks like we need to define things further if we want the Z to change too.

Can anyone point me in the right direction? Would I do this in the Console window instead? Any guidance on that would be appreciated.

9

General / Re: DEM from multiple flights - seam artifacts?

« on: September 22, 2022, 12:07:27 AM »

When we do projects where there are several flights to merge together, there has to be a ground control point in that overlapping area that is shared between FL1 and FL2. Otherwise we'll get this difference in elevations, just due to the error of the GPS on board the UAV.

Maybe you can make up a ground control point, using an available DEM and a high resolution basemap (other satellite imagery). It needs to be tied down.

10

General / Classify Ground Points - multiple orchards of different growth

« on: September 22, 2022, 12:05:23 AM »

I am trying to classify the ground between trees of an orchard. We've done it successfully on vineyards before with satisfactory results, but the entire scene was quite uniform - vines of similar ages.

This new project has orchards of different growths (young to mature).

What are the chances one set of parameters (max angle, max distance, cell size) are going to be suitable for the entire scene? I'm going through a gazillion iterations the past week and not liking any of them.

11

General / Calculating extra bands in Raster Calc then Exporting Ortho

« on: July 15, 2020, 03:33:16 AM »

I have a 6 band Altum Micasense camera. I want to tack on a bunch of extra index calculations so I don't have to do this in ArcGIS.

Bands 1-5 are the visual converted to reflectance
Band 6 is thermal converted to Celsius
Bands 7-12 are my extra calculated bands

I want a 12 band raster with all those calculated bands. I know that "Index Value" in the Export Ortho is how you activate the calculations, but the resulting image is totally grey.

Index Color is for the Palette, checking "Enable Transform" gives only 3 bands. None in Export Ortho gives the original 6 bands.

What is the trick to get all 12 bands with the calculations in the Raster Calculator performed?

I am able to export a raster with the first 6 bands in my list (the normal Altum bands), and a separate raster with the last 6 bands (my 6 bonus calculated bands) just fine, but not all of them together without being grey.

12

General / Re: Micasense Altum Thermal: conversion, resolution questions

« on: May 29, 2020, 11:09:51 PM »

Thank you Paulo! I will say to the client that the TIR has been upscaled to match the other bands.

Micasense shared a bunch of GitHub links today that have the explanation somewhere in there. I didn't know these existed until I made a help ticket with them.

https://github.com/micasense/imageprocessing

https://github.com/micasense/imageprocessing/blob/master/Alignment.ipynb

13

General / Re: Micasense Altum Thermal: conversion, resolution questions

« on: May 29, 2020, 09:46:48 PM »

Can I actually report to my client that the TIR has a 5cm pixel resolution?

It is documented that the TIR resolution/GSD is going to be much more coarse (80cm on the Altum specs sheet). Hence the confusion on what to report.

14

General / Micasense Altum Thermal: conversion, resolution questions

« on: May 27, 2020, 11:47:08 PM »

We are flying the Altum camera at 400ft AGL.

An Agisoft project was created using all 6 bands as in the instructions link:

https://agisoft.freshdesk.com/support/solutions/articles/31000148381-micasense-altum-processing-workflow-including-reflectance-calibration-in-agisoft-metashape-professi

I am experimenting with different ways to convert the thermal band into Cel, ie, Agisoft's Raster Calculator, ArcGIS's Raster Calculator.

In the 6-band Agisoft project (after the 5-band relfectance was exported),  removed the lines with B1/32768; B2/32768; B3/32768; B4/32768; B5/32768 lines, and replaced it with a single line: (B6/100) - 275.13. I've exported the ortho (Index Value selected). Then also another thermal raster where it only said B6 in one line, and did the calculation to Cel in ArcGIS Raster Calculator. Just to compare. Values were same. Good.

Both resulting thermal images from the original 6-band Agisoft project have super fine resolution of 5cm (same for the BRGNIRVRE bands). I am not sure what it's doing to the thermal, upscaling? Can anyone explain?

Then I created a new Agisoft project, but only using the Altum thermal images. This final raster had a 69cm pixel resolution, closer to the 80cm that Micasense reports for a 400ft flight. I also tried to find the difference between my 69cm thermal raster and 5cm thermal raster. While not apples to apples, or a perfect comparison, there were some bigger numbers than we were expecting.

Can anyone tell me how Agisoft is processing the thermal band when it's part of the 6-band multicamera project and why it makes the resolution much finer?

Also those with the Altum, which software do you prefer to convert your centiKelvins to Cel?

15

General / Re: Exporting large orthomosaics

« on: December 01, 2018, 12:00:36 AM »

Does checking the "Write BigTIFF file" in the Export Ortho window work for your purposes? I've exported 50GB mosaics in one piece this way, but I use ArcGIS to view the images. I've used Split in Blocks as well (you'll have to play with the pixel sizing, I've used 5000 or 10,000).