GPS reception ratio detecting apparatus and portable type distance/speed meter capable of indicating GPS signal receiving condition

• US 6,240,366 B1
• Filed: 04/14/2000
• Issued: 05/29/2001
• Est. Priority Date: 04/19/1999
• Status: Expired due to Term

• Current Assignee: NorthStar Systems LLC (Alpha Alpha Intellectual Partners LLC)
• Original Assignee: Seiko Instruments Incorporated (Seiko Group)
• Inventors: Nagatsuma, Hideki, Sakumoto, Kazumi, Odagiri, Hiroshi
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Hernandez, Olga
• Application Number:
  US09/549,361
• Time in Patent Office: 410 Days
• Field of Search: 701/213, 342/357.01, 342/357.05, 342/357.06, 342/357.08, 342/357.12, 455/13.2
• US Class Current: 701/213
• CPC Class Codes: G01S 19/24 Acquisition or tracking or demodulation of signals transmitted by the system synchronisation aspects of direct sequence spread spectrum modulation H04B1/7073
• CPC Class Codes: G01S 19/52 Determining velocity

Abstract

In a GPS reception ratio detecting apparatus, a reception condition of GPS electromagnetic waves in a GPS receiver is judged, and a reception ratio indicative of a ratio of “receivable condition” of GPS electromagnetic waves to a total execution time of the reception process operation thereof is indicated. The GPS reception ratio detecting apparatus is arranged by employing: a GPS (Global Positioning System) receiver for executing a reception process operation for receiving GPS electromagnetic waves transmitted from GPS satellites to acquire positioning data from the received GPS electromagnetic waves; reception judging device for judging as to whether or not the positioning data can be acquired in said GPS receiver every time the reception process operation is carried out; and reception ratio calculating device for calculating a reception ratio indicative of a ratio of a total judgment time at which the reception judging device judges that the positioning data can be acquired in the GPS receiver with respect to a total execution time of the reception process operation.

Claims

1. A GPS reception ratio detecting apparatus comprising:

a GPS (Global Positioning System) receiver for executing a reception process operation for receiving GPS electromagnetic waves transmitted from GPS satellites to acquire positioning data from the received GPS electromagnetic waves;

reception judging means for judging as to whether or not said positioning data can be acquired in said GPS receiver every time said reception process operation is carried out; and

reception ratio calculating means for calculating a reception ratio indicative of a ratio of a total judgment time at which said reception judging means judges that said positioning data can be acquired in said GPS receiver with respect to a total execution time of said reception process operation.

2. A portable type distance/speed meter comprising:

a GPS (Global Positioning System) receiver for executing a reception process operation for receiving GPS electromagnetic waves transmitted from GPS satellites to acquire positioning data from the received GPS electromagnetic waves;

travel distance calculating means for calculating a travel distance of a user based upon said positioning data;

timer means for measuring travel time of the user over said travel distance;

travel speed calculating means for calculating a travel speed of the user based upon both said travel distance calculated by said travel distance calculating means and said travel time measured by said timer means;

average speed calculating means for calculating an average travel speed of the user based upon said travel speed calculated by said travel speed calculating means;

reception judging means for judging as to whether or not said positioning data can be acquired in said GPS receiver every time said reception process operation is carried out;

reception ratio calculating means for calculating a reception ratio indicative of a ratio of a total judgment time at which said reception judging means judges that said positioning data can be acquired in said GPS receiver with respect to a total execution time of said reception process operation; and

display means for displaying thereon said reception ratio.

3. A portable type distance/speed meter as claimed in claim 2 wherein:

said display means includes;

a plurality of reception ratio display units used to display a degree of said reception ratio; and

in response to the reception ratio calculated by said reception ratio calculating means, said plurality of reception ratio display units are selectively displayed.