It isn't much different than how the Air Force was eventually carved out of the Army Air Corps.
https://en.wikipedia.org/wiki/List_of_NRO_launches
"Air Force", "Space Force" are maybe well known to the general population, not many people outside of military/government/tech circles even know the NRO or NGIA exists or what the acronym means. The line gets a bit blurry between Air Force money spent, NRO, NSA, in some regards it's just better to think of it as buckets of how things get labeled within the larger DoD.
My personal favorite mission patch: https://en.wikipedia.org/wiki/USA-247#/media/File:NROL_39_ve...
https://en.wikipedia.org/wiki/National_Geospatial-Intelligen...
https://www.nextgov.com/people/2004/02/whats-in-a-name/21950...
Although the new title is four words long, the agency will officially use a three-letter acronym. This is by design, according to NGA officials, who feel that the new title more accurately reflects the agency's true mission, which is to provide intelligence and analysis rather than simply reproducing maps and imagery.
There is one NGIA on the Wikipedia page, in the title of a document from 2014:
https://www.governmentattic.org/11docs/NGIAoigGAMPC_2007-201...
So more like a common misspelling?
" "NGIA" intelligence mapping"
It'll turn up a ton of results where people external call it NGIA including a number of .edu sources...
In some ways I guess it's a bit of a stylistic choice, putting a letter for each of the four words of its name, much as how BBC News does not always capitalize all acronyms. Copy and pasting from their style guide:
"acronyms
Use the abbreviated form of a title without explanation only if there is no chance of any misunderstanding (eg UN, Nato, IRA, BBC). Otherwise, spell it out in full at first reference, or introduce a label (eg the public sector union Unite).
Where you would normally pronounce the abbreviation as a string of letters - an initialism - use all capitals with no full stops or spaces (eg FA, UNHCR). However, our style is to use lower case with an initial cap for acronyms where you would normally pronounce the set of letters as a word (eg Maga, Sars, Aids, Nasa, Opec, Apec).
There are a few exceptions:
The National Institute for Health and Care Excellence is capped up ie NICE
Special educational needs and disabilities becomes SEND
The UK Independence Party is capped up ie UKIP
Strategic Health Authority becomes SHA ("Sha" looks like a typo)
Seasonal Affective Disorder becomes SAD ("Sad" would be confusing)
Where a capped-down acronym risks being misunderstood as a word.
When abbreviating a phrase, rather than a name or title, use lower case (ie lbw, mph)."
The mission scope of the various intelligence agencies has evolved a lot over time as capabilities and requirements have changed. Even the histories of how these independent agencies came to exist is pretty interesting.
And yeah, that mission patch is fire.