Shoran installation at Port Clarence.

Diagram of range-range navigation geometry. Hydrographic Manual

Erecting EPI (Electronic Position Indicator) antenna. EPI was a medium frequency system that was useable out to 200 miles. Invented within the Coast and Geodetic Survey

EPI antenna mast used in Bering Sea operations.

Carl Aslakson monitoring EPI receiver on HYDROGRAPHER. Field testing of EPI - first medium frequency survey navigation system. Invented within the Coast and Geodetic Survey

First field testing of Raydist on the SOSBEE. Medium frequency survey navigation system

Raydist watch on the HYDROGRAPHER. Hydrographic surveying operations

Electronic survey equipment on HYDROGRAPHER. Field testing of electronic survey equipment

Setting up a Raydist tower. Base plate with tower and cable - tower assembled from 10-foot aluminum sections . Party off of wire drag vessels WAINWRIGHT and HILGARD. Photograph #1 of sequence

Setting up a Raydist tower. Preparing the gin pole - basically a large lever arm. Party off of wire drag vessels WAINWRIGHT and HILGARD. Photograph #2 of sequence

Setting up a Raydist tower. Ready to erect tower. Party off of wire drag vessels WAINWRIGHT and HILGARD. Photograph #3 of sequence

Setting up a Raydist tower. Lifted a little. Party off of wire drag vessels WAINWRIGHT and HILGARD. Photograph #4 of sequence

Setting up a Raydist tower. About half-way up. Party off of wire drag vessels WAINWRIGHT and HILGARD. Photograph #5 of sequence

Setting up a Raydist tower. Most of the way up. Party off of wire drag vessels WAINWRIGHT and HILGARD. Photograph #6 of sequence

Setting up a Raydist tower. Tower in position and ready to transmit. Party off of wire drag vessels WAINWRIGHT and HILGARD. Photograph #7 of sequence

Erecting a 100-foot Raydist tower with a 30-foot gin pole. Party off of PATHFINDER

NOAA helicopter supporting Raydist tower installation. Party off of SURVEYOR

Electronics for loading Raydist tower.

Operational Raydist station at Kamishak Bay. Installation by party off of PATHFINDER

ARGO tower being installed. Installation by party off of FAIRWEATHER

Raydist tower at Cape San Blas. Note man at top of tower making final adjustments. Installed by party off of NOAA Launch 1257

Assembling Raydist tower sections. Party off of NOAA Launch 1257

Electronics for loading Raydist tower. Party off of NOAA Launch 1257

Erecting ARGO navigation tower. Party off of MT. MITCHELL

Erecting ARGO navigation tower. Party off of MT. MITCHELL

Erecting ARGO navigation tower. Making final adjustments - not a good job for acrophobics. Party off of MT. MITCHELL

Erecting ARGO navigation tower. Making final adjustments - not a good job for acrophobics. Party off of MT. MITCHELL

Erecting ARGO navigation tower. Making final adjustments - not a good job for acrophobics. Party off of MT. MITCHELL

Using Coast Guard light tower as base for ARGO whip antenna. Party off of PEIRCE

Hydrotrac navigation system antenna in lower Cook Inlet. Party off of PATHFINDER

ARGO shipboard electronics package. On PEIRCE

Plotting Raydist readings with Odessey protractor. Note circular arcs on boat sheet denoting range-range navigation. Launch party off of PIONEER

Raydist strip chart record used to keep track of individual navigation rates. These strip charts required continuous monitoring by a watch-stander. Used to assure navigational accuracy during hydrographic surveying operations. First tests of Raydist on SOSBEE in 1954. Used for over 40 years with various systems

ARGO strip chart record on SURVEYOR.

ARGO strip chart record on PEIRCE.

Maintaining Raydist strip chart watch.

Testing moored instrument package for GATE Project. Operations on NOAA Ship WHITING

Testing moored instrument package for GATE Project. Operations on NOAA Ship WHITING

Testing moored instrument package for GATE Project. Operations on NOAA Ship WHITING

Testing moored instrument package for GATE Project. Operations on NOAA Ship WHITING

Testing moored instrument package for GATE Project. Operations on NOAA Ship WHITING

Bringing Shoran gear up a cliff for shore camp by using strongback. Operations off of SURVEYOR

Bringing Shoran gear up a cliff for shore camp. Operations off of SURVEYOR

Geometry of first microwave navigation system tested by C&GS. Converted range readings to lines of equal angles between stations. Used for high-accuracy inshore work. After testing, determined not sufficiently accurate for large-scale surveys. Tested on SOSBEE

Microwave navigation system - shore installation on tower. Tower merely a platform and not loaded. Tested on SOSBEE

Microwave navigation system - shore installation on tower. Tower merely a platform and not loaded. A line-of-sight system -- the higher the tower, the further the reception. Tested on SOSBEE

Installing a microwave navigation system. Installing system on Georgia Coast day marker. Party off of WHITING

Erecting a 30-foot tower for a microwave transponder. Assistant Boatswain "Colonel" Sanders. Party off of WHITING

Chief Electronics Technician Slim Tittle hooking up batteries. Power source for microwave navigation system. Party off of WHITING

Carrying batteries for microwave navigation system. Party off of WHITING. Party off of WHITING