Adjectives or compound noun?

My students were asked, in an exercise in their published workbook (in which there are sometimes mistakes), to identify the noun or nouns in a sentence within a passage about carrier pigeons being used for scientific research. The book said that "Each bird carried a GPS satellite tracking receiver on its back."(Punctuation as written: i.e. no commas.) The answer book identified 'GPS', 'satellite' and 'receiver' as separate nouns within the sentence.

I am confused. To me, 'GPS', 'satellite' and 'tracking' could be regarded as adjectives describing the only noun in the sentence, being 'receiver'. Either that or all four words could be forming a compound noun: the name of the object in question is a 'GPS satellite tracking receiver', rather like a 'bedside table' being one physical object but with two words to describe it.

I am sure that the answer book is wrong and that these are not separate nouns, but I am unclear whether there are three adjectives and a single word noun in this sentence, or whether there is a four-word compound noun and no adjectives.

In the noun phrase a GPS satellite tracking receiver, the words GPS, satellite and receiver are nouns and tracking is a present participle. The head noun is receiver, and all other nouns and the participle function as adjectives. A noun functioning as an adjective is grammatically termed as Attributive Noun or Noun Adjunct

attributive noun (plural attributive nouns)

(grammar) A noun that modifies another noun attributively and that is optional (that is, it can be removed without affecting the grammar of the sentence); a noun used as an adjective. For example, in the compound noun "chicken soup", the attributive noun "chicken" modifies the noun "soup". (Wiktionary)

Theses attributive nouns can be written as open compounds (separately), hyphenated compounds or closed compounds (as single words). There’s no rule governing which become single words and which stay two.

When one noun clearly functions as an adjective modifying another noun, no hyphen is needed. However, when the two nouns are in equal standing, use a hyphen—for example, city-state, poet-novelist, closet-bathroom. (Grammarist)