Reading and plotting .raw file data in R

Question

I have .raw file data which contained the climate data. The data was pre-processed by other people (not me).

This is the correct image plotted by other software.

enter image description here

Now I want to plot and re-analyze the data in R.

I have tried the code below based on answers I have found here and elsewhere:

image_width=961
image_height=481

library(hexView)

raw_image <- readRaw("D:/IDL/boa/sst_20200621-GRAD_MAG.raw")
image_matrix <- matrix(raw_image$fileRaw, nrow = image_height, ncol = image_width, byrow = TRUE)
plot(as.raster(image_matrix))

And I got this.

enter image description here

So I back to check the data I read. I found that the data I import isn't numerical values. It looks like this:

> str(raw_image)
List of 10
 $ width  : NULL
 $ offset : num 0
 $ nbytes : num 1848964
 $ fileRaw: raw [1:1848964] 00 00 c0 7f ...
 $ fileNum: NULL
 $ machine: chr "hex"
 $ type   : chr "char"
 $ size   : num 1
 $ endian : chr "little"
 $ signed : logi TRUE
 - attr(*, "class")= chr "rawBlock"

I also tried to modify the code like this:

> raw_image <- readRaw("D:/IDL/boa/sst_20200621-GRAD_MAG.raw", human="real")
> str(raw_image)
List of 10
 $ width  : NULL
 $ offset : num 0
 $ nbytes : num 1848964
 $ fileRaw: raw [1:1848964] 00 00 c0 7f ...
 $ fileNum: num [1:231120] 2.25e+307 2.25e+307 2.25e+307 2.25e+307 2.25e+307 ...
 $ machine: chr "hex"
 $ type   : chr "real"
 $ size   : num 8
 $ endian : chr "little"
 $ signed : logi TRUE
 - attr(*, "class")= chr "rawBlock"

But it still not work, because the value of the data should be between 0.0 to 0.3, not 2.25e+307 or 00 00 c0 7f.

So my question is how to correctly import the .raw file data.

Thanks in advance for any help. It will be much appreciated!