The phrase "in-depth survey" is correct and usable in written English.
You can use it when referring to a comprehensive study or investigation. For example, "Researchers conducted an in-depth survey of the local community to determine their needs."
A large in-depth survey of older Americans has yielded a mixed appraisal of the new Medicare prescription drug benefit.
One room offers an in-depth survey of American stamps; another space provides a broad international sampling.
The first in-depth survey of Chagall's art since 1985, the show costs an extra $5 on top of the usual $10 admission.
In 2013, an in-depth survey by Ipsos MORI revealed that Britons vastly overestimate the number of British immigrants, Muslims and benefit fraudsters.
"It's an in-depth survey, and we felt a vacation day would be a good incentive to get workers to complete it".
An in-depth survey of the experiences of British Muslims targeted because of their faith found that many are left feeling trapped after suffering verbal or physical abuse.
The study, being published Monday in the journal Pediatrics, analyzed an in-depth survey conducted in 2004 by the Centers for Disease Control and Prevention that asked people how they got health care.
In a more serious vein, I try to keep up with The Economist, and, in particular, its in-depth survey pieces, which are a good way to monitor what's going on around the world.
They conducted an in-depth survey with current account executives, and identified a situation in which our sales people were duplicating efforts by entering the same data into two different systems.
Group homes for teenage foster children in New York City have long had a rough reputation, but an in-depth survey of adolescents who have graduated from the homes and of judges, lawyers and caseworkers who have worked with them shows just how dangerous such institutional care can be.
This first formal critical conference at the Village Vanguard, 178 Seventh Avenue South, between 11th Street and Waverly Place, will deal with gay jazz musicians, an in-depth survey of jazz musicians commissioned by the National Endowment for the Arts, and the aesthetic of jazz as perceived in the language of critics and academicians.
