# How to perform Radiometric Calibration with Reflectance Plate without using Camera and Sun Irradiance information?

**URL:** <https://community.pix4d.com/t/how-to-perform-radiometric-calibration-with-reflectance-plate-without-using-camera-and-sun-irradiance-information/19130>\
**Category:** PIX4Dmapper\
**Created:** [July 27, 2021, 1:05pm UTC](https://community.pix4d.com/t/how-to-perform-radiometric-calibration-with-reflectance-plate-without-using-camera-and-sun-irradiance-information/19130 "2021-07-27T13:05:33Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![konlavach.mengsuwan](https://avatars.discourse-cdn.com/v4/letter/k/7c8e57/32.png) [@konlavach.mengsuwan](https://community.pix4d.com/u/konlavach.mengsuwan)\
**Post date:** [July 27, 2021, 1:05pm UTC](https://community.pix4d.com/t/how-to-perform-radiometric-calibration-with-reflectance-plate-without-using-camera-and-sun-irradiance-information/19130/1 "2021-07-27T13:05:33Z")

</div>

Dear all,

I have **DJIP4 Multispectral** datasets in the agriculture area.  
I have 3 reflectance plates (10%, 20%, 90%) on the ground while the drone was captured.  
The Camera and Sun Sensor were also on during the flight.

I would like to process the images with Pix4D, Ag Multispectral.  
However, I want to process without Camera information (ISOSpeed, ApertureValue, ExposureTime) and Sun Irradiation (Irradiance, SunSensor).

**Question 1:** : Would it be possible to select Radiometric Processing → Correction Type: No Correction, while I still want to provide the Reflectance Factor of my Reflectance plates.

**Question 2:** : If the above answer is not possible. How to delete the Camera and Sun Sensor information from Exif and XMP? I have tried with **ExifTool on Window** and here are the results:

Camera:

1. ISOSpeed: Can delete
2. Aperture: Can delete on (fnumber, ApertureValue, MaxApertureValue) but not on (Aperture)  
I am not sure which Aperture value does Pix4D uses for the process.
3. ExposureTime: Can not delete, only possible to set to 0.

Sun Sensor:  
Irradiance, SensorGain, SensorGainAdjustment, SensorIndex, SunSensor, SunSensorExposureTime, IrradianceExposureTime: Can read, but can not delete:

```auto
exiftool -xmp:Irradiance DJI_0011_2020.TIF
exiftool -xmp:Irradiance= DJI_0011_2020.TIF

```

```auto
Warning: Tag 'xmp:Irradiance' is not defined
Nothing to do. 

```

**Question 3:** : Which Reflectance Plate (10%, 20%, 90%) is the best (make the best sense) on Agriculture area for Vegetation Indices.

Very thanks in advance for your comments.  
Konlavach

---

<div class="post-metadata">

**Author:** ![Fernanda\_Bosmediano](https://sea2.discourse-cdn.com/pix4d/user_avatar/community.pix4d.com/fernanda_bosmediano/32/323_2.png) [@Fernanda\_Bosmediano](https://community.pix4d.com/u/Fernanda_Bosmediano)\
**Post date:** [August 9, 2021, 12:18pm UTC](https://community.pix4d.com/t/how-to-perform-radiometric-calibration-with-reflectance-plate-without-using-camera-and-sun-irradiance-information/19130/2 "2021-08-09T12:18:08Z")

</div>

> [@konlavach.mengsuwan](#):
>
> reflectance plates

Hi,  
Thanks for your patience. Regarding your questions:

Question 1: It is not possible. If you select the No correction option, then the option to import reflectance panel images is disabled.

Question 2: You can try using exiv2: [https://exiv2.org/](https://exiv2.org/)  
You can create a .bat file using the following info:

```auto
@echo off
for %%v in (*.TIF) do (
	echo %%v
	exiv2 "-Mreg Camera http://pix4d.com/camera/1.0" "-Mdel Xmp.Camera.IrradianceGain" "%%v

)

```

Question 3: I am not sure about the reflectance plates you have. Can you send some images? Or give me more details about them?